Outcomes from restoration projects are often difficult for policymakers and stakeholders to assess, but this information is fundamental for scaling up ecological restoration actions. We evaluated technical aspects of the interventions, results (ecological and socio-economic) and monitoring practices in 75 restoration projects in Mexico using a digital survey composed of 137 questions. We found that restoration projects in terrestrial ecosystems generally relied on actions included in minimal (97%) and maximal (86%) intervention, while in wetlands, the preferred restoration strategies were intermediate (75%) and minimal intervention (63%). Only a third of the projects (38%) relied on collective learning as a source of knowledge to generate techniques (traditional management). In most of the projects (73%), multiple criteria (>2) were considered when selecting plant species for plantings; the most frequently used criterion was that plant species were found within the restoration area, native or naturalized (i.e., a circa situm criterion; 88%). In 48% of the projects, the biological material required for restoration (e.g., seeds and seedlings) were gathered or propagated by project implementers rather than purchased commercially. Only a few projects (between 33 and 34%) reached a high level of biodiversity recovery (>75%). Most of the projects (between 69 to71%) recovered less than 50% of the ecological services. Most of the projects (82%) led to improved individual relationships. The analysis revealed a need to implement strategies that are cost-effective, the application of traditional ecological knowledge and the inclusion of indigenous people and local communities in restoration programs at all stages—from planning to implementation, through monitoring. We also identified the need to expand research to develop effective tools to assess ecosystems’ regeneration potential and develop theoretical frameworks to move beyond short-term markers to set and achieve medium- and long-term goals. Cautious and comprehensive planning of national strategies must consider the abovementioned identified gaps.
Citation: Méndez-Toribio M, Martínez-Garza C, Ceccon E (2021) Challenges during the execution, results, and monitoring phases of ecological restoration: Learning from a country-wide assessment. PLoS ONE 16(4): e0249573. https://doi.org/10.1371/journal.pone.0249573
Editor: Tunira Bhadauria, Feroze Gandhi Degree College, INDIA
Received: October 22, 2020; Accepted: March 21, 2021; Published: April 6, 2021
Copyright: © 2021 Méndez-Toribio et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper.
Funding: MMT acknowledges CIFOR and CIByC for the financial support granted during postdoctoral research at UAEM. This study was financed by the Department of International Development of the United Kingdom (DFID) through the KNOWFOR project and under the activity “La restauración de ecosistemas terrestres en México: Situación actual, tendencias, necesidades y oportunidades”. EC is thankfull to the DGAPA-PAPIIT IN300119 project.
Competing interests: The authors have declared that no competing interests exist.
Restoration intervention is implemented to restore damaged ecosystems. Minimal intervention, called also “passive restoration”  or “unassisted forest regeneration” , includes actions to remove chronic disturbance for allowing natural succession to proceed . This intervention is considered cost-effective for large-scale restoration . Fostering natural succession requires low levels of disturbance at the landscape or local level . Intermediate restoration or assisted natural regeneration (ANR) aims to accelerate the natural succession process by removing sources of disturbance (e.g., fire, grazing, or wood harvesting) or reducing impediments to natural forest succession [e.g., soil degradation, competition with weedy species, lack of seeds; 6,7]. The ANR technique is usually a simple, less expensive than maximal intervention, and effective for converting areas of degraded vegetation to more productive forests . The implementation of ANR is suggested at intermediate levels of degradation . Finally, maximal intervention involves establishing restoration plantings, including enrichment planting : establishment of valuable timber species in species poor forest . This approach is the most effective for recovering biodiversity, but it is usually an expensive technique [10,11]. Defining which level of intervention to apply is a difficult task . For instance, before plantings are established, it is frequently necessary to construct civil infrastructure for erosion control  or assess chronic disturbance by establishing an initial diagnosis of the degraded ecosystem [7,14]. In addition, although Traditional Ecological Knowledge (TEK) from local communities, such as Indigenous Peoples and Local Communities (IPLCs), has been recognized to have a valuable contribution to projects [15,16], TEK is currently almost never considered in restoration programs [17–21]. Restoration plantings involve the challenge of finding seeds with high genetic diversity  and selecting species with high performance in the context of climate change [23,24]. Criteria for selecting planting material, however, are often poorly related to restoration objectives  or even overlooked by practitioners . Tree species for assisted succession are selected for their availability in nurseries  or some desired traits (e.g., abundant foliage, good root development, resistance to pests) rather than for their role in a particular ecological process or ecosystem function . Projects that establish plantings to increase primary productivity, pollination services, or seed dispersal are indeed scarce [27–29]. In summary, the adequate selection of the level of restoration intervention depends on previous ecological knowledge, degree of disturbance, objectives, available budget, and restoration scale.
After planning and executing interventions, results, progress, and effectiveness should be evaluated . Monitoring enables assessing restoration outcomes compared to initial ecosystem conditions or to a reference ecosystem . Evaluate restoration progress allows knowing whether objectives have been achieved . In addition, collaborative and cross-scalar monitoring generates valuable information for social learning and adaptive management , which is an iterative process allowing projects to adapt to unexpected threats and to learn from the process [30,33] There is still, however, a strong debate about what variables should be monitored [34–37] given that some projects can take decades before showing results [38,39]. In practice, monitoring should include biophysical and socio-economic variables  and a multi-scalar, multi-site monitoring approach is needed . Nevertheless, projects that have a holistic vision are scarce, and the contribution that IPLCs can make to assess the progress of projects is still insufficiently studied . Evidence to date about monitoring of Latin American restoration projects indicates a lack of forecast and proper planning based on a clear conceptual framework . For example, in Colombia, 50% of projects did not include medium- or long-term variables, and only 5% included social variables . Adequate monitoring is fundamental for determining whether restoration projects are reaching their goals and for verifying their overall effectiveness and success.
Because of the magnitude of the degradation and destruction of ecosystems in Latin America and worldwide , the restoration of ecosystems and landscapes is an international priority. The Aichi Target 15 of the Convention on Biological Diversity called countries to restore 15% of degraded or deforested forests, highlighting the recovery of biodiversity . The Bonn Challenge, launched in 2011 by Germany and the IUCN, is a global effort to restore 150 million hectares of the world’s deforested and degraded land by 2020, as well as 350 million hectares by 2030 . This initiative, later supported and broadened by the New York Declaration on Forests at the 2014 UN Climate Summit, is based on a forest landscape restoration (FLR) approach . Additional initiatives include the Zero Net Land Degradation , which calls leaders to avoid degradation of productive lands and restore degraded lands and the Initiative 20x20 for Latin America , which promotes the recovery of productivity on degraded lands. In addition, in the Sustainable Development Goals , restoration is explicitly annotated in objective 15 (“Life on Earth”) to fight desertification and to stop and reverse land degradation. Finally, the United Nations General Assembly has declared 2021to 2030 the “Decade on Ecosystem Restoration” [49,50]. These global initiatives offer unparalleled political and economic opportunities for halting and reversing environmental degradation.
None of the global initiatives, however, include specific strategies for restoring ecosystems. Available international guidelines on implementation and monitoring are included in the Society for Ecological Restoration International Primer on Ecological Restoration , the International Principles and Standards for the Practice of Ecological Restoration [14,52], and the “Practitioner’s Guide” of the International Union of Forest Research Organization . To face the multiple challenges of ecosystem restoration, it is important to analyze information about the strategies implemented on the ground as well as the results and monitoring scheme used to evaluate those results. Here, we systematically analyze the information obtained from a national assessment of 75 projects performed in Mexico, including the following: (i) technical aspects and the interventions executed, (ii) ecological and socioeconomic results, and (iii) monitoring of the actions implemented, including criteria and the person responsible for carrying it out. Understanding how restoration actions are conducted allows the identification of gaps in implementation and thus the design of policies and prioritization of studies needed to improve restoration strategies . Moreover, information about the interventions performed, the results of restoration, and the variables monitored are fundamental for scaling and prioritizing actions to the landscape level .
Materials and methods
Data were collected between 2015 and 2016. Six complementary procedures were used to identify the restoration projects: (1) a Google search using the keywords restaur*, recuper*, restor*, recover* México and vegetación; (2) direct consultations with restoration practitioners and active conservation institutions; (3) review of conference abstracts available since 2000 from the meetings of the Botanical Society of Mexico, AC, the Mexican Scientific Society for Ecology, the Society for Ecological Restoration held in Mexico and the first Mexican Ecosystem Restoration Symposium in 2014; (4) search for on-line documents from institutional and academic libraries; (5) seek information on restoration projects in specialized databases; the search was performed in the Global Restoration Network, EcoIndex, and the databases of the Commission for the Knowledge and Use of Biodiversity (CONABIO), the National Institute of Ecology and Climate Change (INECC), and the Mexican Network for Environmental Restoration (REPARA) and (6) consultation of the Mexican Conservation Board to identify individuals, academic and government institutions, and civil society organizations with a mission that included ecological restoration . This allowed the identification of 293 entities involved in ecological restoration actions. Through this ample search, we identified a sample of 188 projects, which was later reduced to 150 projects after excluding projects in marine or aquatic environments and those for which only information from the diagnostic stage was available. Projects were also excluded from analysis when no technical reports were available or when we were unable to contact the project manager by email or phone. The projects were also ineligible when the survey was not completed during the dates available or when institutions did not have documents about the projects.
The information on the restoration projects was collected through a semi-structured digital survey via LimeSurvey ver. 2.65.0 (https://www.limesurvey.org) or was extracted from available technical reports. This survey was adapted to the Mexican context from the assessment protocol for restoration projects designed by Murcia and Guariguata for Colombia . The survey consisted of open and closed multiple choice questions. The survey was sent to people involved in the 150 projects mentioned above. All the participants in the survey were given an information sheet about the project and asked to provide informed consent in writing. Research was approved by the Universidad Autónoma del Estado de Morelos and the Instituto de Ecología, A.C. and in compliance with its code of research integrity. Additionally, people and institutions were contacted by phone to verify details. The survey was open for three months, after which we received information from 58 projects. For an additional 17 restoration initiatives, information was obtained from published technical reports. It was not always possible to obtain information for all the fields of the survey; thus, sample sizes varied among variables. In results, we report the number of cases containing full information at each section. The answers were accepted as bona fide as no field visits were made to corroborate the accuracy or veracity of the reported data.
The complete list of projects and the entire survey composed of 137 questions can be consulted in the following publication: La restauración de ecosistemas terrestres en México: Estado actual, necesidades y oportunidades . Here, we analyze information from questions available in S1 Appendix, which addressed the following: (i) the technical aspects of the interventions executed, (ii) ecological and socioeconomic results and (iii) monitoring actions, e.g., type of monitoring and responsible parties. The section of technical aspects compiles information on the type of intervention, source of the techniques implemented to recover flora and fauna, and the origin of biological material. The section of ecological results explores progress towards targets and goals regarding initial conditions and the reference ecosystem. The section of socio-economic results examines individuals’ perceptions of collaboration among organizations, individuals, and institutions. We also included in this section whether because of restoration there was an application or creation of economic incentives. Finally, questions in the section of monitoring actions gather information about planning, variables used, monitoring type, and the identity of the executors, as well as whether adaptive management was included. The responses from open questions were reduced to categorical variables measured in the short-, middle-, and long-term. The information of projects was organized in Excel® spreadsheets and further processed using the "plyr", "dplyr", "tibble" and "tidyr" libraries of the free access R environment .
Technical aspects of execution
Interventions carried out.
Fifty-nine of the projects (79%) were developed in terrestrial ecosystems, while only 16 (21%) were in wetland ecosystems. Of these, 12 (75%) gave information on the interventions carried out (Table 1). For 44% (N = 33) of the projects, civil infrastructure works were required before implementing restoration actions. Minimal intervention was the most frequent restoration action in 97% of terrestrial ecosystems. Disturbance exclusion (78%) to foster natural succession (77%) was the most frequent restoration strategy at this level of intervention. Maximal interventions were in second place, and plantings of species with specific ecological attributes (61%) and mixed tree plantings (47%) were the most frequent restoration strategies at this level of intervention. Intermediate interventions were mentioned in only 31% of projects, including eradication of alien and/or invasive species (61%) and nucleation, which were the preferred implemented actions in this category (44%).
In 83% of wetland ecosystems, minimal interventions were the most frequently implemented intervention (Table 1). Ninety percent of projects included promoting natural succession and in 80% the re-establishment of a hydrological regime was required. Intermediate interventions were the second most common in wetland ecosystems; 42% of projects required the transfer of sediments and/or seed banks. Finally, maximal intervention was established in 67% of the projects and included the sowing or transplanting of emerging plant species.
Source of implemented techniques.
The techniques used in restoration processes were most frequently developed for the project and executed by their creators (80%; N = 69); some were taken from previously developed projects (36%). Collective learning (through a knowledge dialogue with local people) was not a particularly frequent source of implemented techniques (38%; traditional management). To a lesser degree, techniques were adapted from national (23%) or international literature (13%), and rarely were the used, protocols given by the convener or contracting institution (12%).
Criteria used for selection of biological material and its source.
Biological material selection was most often multicriterial (Fig 1). In 88% of projects, the biological material was selected under a circa situm criterion, i.e., that species were native or naturalized to the restoration zone. Forty-eight of the projects selected multipurpose species, and 47% considered the local availability of seeds or seedlings. In 44% of the projects, species that facilitate ecological succession were selected (Fig 1). Ease of propagation or reproduction (36%), commercial availability of seeds or germplasm (14%) or species’ inclusion on lists generated from government or other institutions (6%) were not frequent criteria.
(i) circa situm: Species within to the restoration zone (natives or naturalized), (ii) multipurpose species, (iii) local availability of seeds and seedlings (extracted from reference neighborhood or nearby sites), (iv) species that facilitate succession (nursery plants or catalyzing species, for example, species producing fruits that feed local fauna, nitrogen fixers, soil fixers, etc.), (vi) ease of propagation or reproduction, (vii), commercial availability of seeds or germplasm, and (viii) listed species by convener institutions. The total number of projects analyzed was 64.
With respect to the source for acquiring the biological material used, in 48% (N = 64) of the projects, implementers propagated the material themselves, while in 40% of the projects, the material was purchased from local nurseries. Twelve percent of the projects mentioned other sources, such as the extraction of seedlings from nearby sites or rescue from sites that were slated for exploitation.
Ecological, social, and economic aspects of restoration projects
Only a few projects reached a high level of biodiversity recovery (Fig 2). For example, in 29% of the projects, recovery of biodiversity was between 1 and 25% relative to the initial conditions (Fig 2A), and only 16% of projects claimed 75 to 100% recovery. The situation was similar considering the biodiversity recovery relative to a reference ecosystem (Fig 2B).
Percentage of projects in each of four class types (inside the donuts) indicating degree of biodiversity recovery compared with (a) the initial condition of the ecosystem and (b) a reference ecosystem. The total number of projects analyzed was 55 in (a) and 50 in (b).
The recovery of provisioning ecosystem services was less than 50% in 69% of projects when using the initial ecosystem conditions as the reference point (Table 2). When recovery of services was compared with the reference ecosystem, the percentage of projects increased (71%). Most of the projects recovered less than 50% of regulating services regardless of whether the comparison was with the initial ecosystem conditions or with the reference ecosystem.
For 82% of the projects, it was perceived that relationships among individuals improved, as did collaboration among non-governmental organizations (67%) and scientific or educational institutions (65%; Fig 3).
The chart shows the percentage of projects where an improvement, a setback or a similar collaboration was perceived in ecological restoration actions among non-governmental organizations, individuals and scientific or educational institutions. The total number of projects analyzed was 57.
In most of the projects, no monetary incentives were applied or created (52%; Table 3). Moreover, only 8% requested payment for ecosystem services, and only 4% of projects applied voluntary market mechanisms such as a carbon credit. The employment of local community members for the implementation of projects was an incentive that was not included among multiple choice options but was mentioned in open responses by surveyed individuals (25%).
Monitoring practices in restoration projects
In 43 projects (57%), a monitoring plan was established a priori (N = 75). Among these, 20 (47%), indicated that there was funding set aside for monitoring actions. Only 35 (81%) projects provided information on the frequency of evaluations. Annual evaluations were the most frequent (51%; 18 cases), followed by evaluation every six months (23%; 23 cases), every three months (20%; 7 cases), monthly (17%; 6 cases) and every two months (9%; 3 cases).
Generally, variables from more than one category were used for monitoring (Table 4). Most of the projects (88%) monitored several short-term changes and one long-term variable (88%). These include plant survival and growth, changes in vegetation structure (74%), environmental and physicochemical parameters of water, such as site quality or ecosystem water quantity (28%), indicators of erosion control (23%), and vegetation cover (23%). Medium-term changes, like colonization of fauna (21%), carbon accumulation, ecosystem productivity or soil nutrients increases (14%), and secondary succession (12%) were assessed in 40% of the projects. The only long-term variable—anthropic perturbation and human settlements—was measured in 88% of projects. Social changes, i.e., community perception of social or environmental benefits of the restoration project, were monitored in only 2% of projects (Table 4).
For 69% of the projects, the scientific method was the most frequently used to measure success, progress, or effectiveness of actions. Programmatic monitoring (i.e., monitoring activities laid out a priori at specific times during the development of the project) and participatory (collaborative) monitoring were used in equal percentages (31% each). Scientific monitoring with local knowledge was the least used method to measure success (17%) (Fig 4).
The total number of projects analyzed was 36.
In most of the projects, monitoring was led by academics (54%; Table 5). Community members participated in monitoring in 32% of projects. Government institutions (32%) and academics (24%) handled the legal part (established by law) of the monitoring phase. Financial resources for monitoring were mainly provided by the government (70%) and academic sector (38%). The private sector was only rarely responsible for the technical or legal aspects of project monitoring (6 and 5%, respectively), and community members only rarely participated as funders (6%). No international institutions were the main parties responsible for the technical, legal, or financial aspects of restoration projects’ monitoring.
Information related to adaptive management was gathered from 27 projects, of which 16% reported that they had not yet analyzed results, 19% reported that they already had results showing the need to adjust but had not yet implemented the required changes, and 7% reported a diagnosis and that they were making adjustments.
Ecological restoration on the ground
Minimal intervention such as disturbance exclusion to foster natural regeneration or re-establishing natural fire regimes were the preferred implementation approaches. All of these actions involve removing disturbance from an ecosystem [1,58] to allow natural succession to begin . Favoring natural regeneration can potentially be applied to very large areas . For example, unassisted regeneration has been the main strategy implemented in large scale-restoration projects (>100,000 ha) in Latin America . Restorations methods based on natural regeneration are considerably less expensive than tree plantings, making it more cost-effective on a large scale . For instance, the restoration of more than 3000 ha in the state of Rio de Janeiro, Brazil, would have cost US $15.1 million using tree plantings . Although natural regeneration is frequently adopted because of the usually limited resources in the restoration projects [41,56], their implementation should consider the potential for natural regeneration, and the landscape and social context . Overall, the potential for natural regeneration increases in agricultural landscapes when the size, duration, and severity of disturbance [64,65], or degree of transformation is low . Natural regeneration potential is also low in climatic hardness conditions [temperature and vapor pressure deficit; 64]. At the landscape scale, the most critical factors for a high natural regeneration potential are the proximity to existing forested areas and the dispersal capacity of species . Lastly, human development is also a predictor of the potential for natural regeneration since the lowest recovery of biodiversity by natural regeneration is likely to occur in countries with an intermediate rating Human Development Index [HDI; 66]; the HDI is based on life expectancy, education, and income (http://hdr.undp.org/en/content/human-development-index-hdi). Opting for minimal intervention actions is viable when the natural regeneration potential is high. Thus, it is fundamental to evaluate natural regeneration potential a priori to deciding the level of intervention to apply.
Restoration plantings are frequently implemented in restoration projects. Although this method requires a large amount of financial resources  and prior knowledge of plant performance to be successful, its implementation removes several biotic (e.g., competition, dispersal limitation) and abiotic (e.g., environmental conditions) barriers to natural succession . Restoration plantings are generally established in small-scale projects and/or in heavily degraded landscapes . In Mexico, 67% of the projects were small in scale (< 1,000 ha, mean = 94.6 ha), and the most frequently identified threats were extensive cattle ranching and fragmentation. In addition, the majority of the projects were financed by the government [56,63]. These results from a previous analysis of the characterization of projects in Mexico suggest that most of the restoration initiatives were in highly degraded and fragmented areas, which would explain why maximal intervention was also heavily represented there. Although restoration plantings are usually expensive , their implementation in Mexico was frequently financed and promoted by government institutions such as the National Forestry Commission . A similar situation has been found in Colombia, in which most of the interventions are on an even smaller scale (< 100 ha, mean = 29 ha). The main threats are cattle ranching and agriculture in fragmented ecosystems; furthermore, the most frequently used restoration technique is the plantings of trees and shrubs, and a great proportion of projects are government financed .
An alternative to these restoration strategies is assisted natural regeneration (ANR). ANR reduces or eliminates the costs associated with propagating, raising, and planting, making it a simpler, less expensive, and usually effective technique for recovering forest productivity . Eradication of alien and/or invasive species, nucleation, herbicides application and seeding were intermediate interventions applied to a lesser extent. ANR strategies are often used to remove some of the biotic barriers to natural succession and therefore accelerate recovery . For example, alien or invasive species usually compete intensely with local species for resources, slowing down or arresting natural succession . To eliminate this barrier, competing plants can be removed manually, with tools (e.g., machetes), or by applying herbicides [71,72]. These ANR strategies are generally used in an adaptive management context in conjunction with other levels of intervention or are targeted to solve a particular problem. For example, the proliferation of climbing plants in early successional habitats is a frequent phenomenon that limits the development of plants [72,73]. In both tropical and temperate forest, ruderal climbing plants or woody lianas are favored by disturbance, and affect tree growth and forest biomass and hence arrest forest succession [74,75]. One way to facilitate forest regrowth is by removing those plants [76–78]. ANR represents an alternative way for recovering degraded ecosystems at intermediate levels of degradations at a reasonable cost.
As one might expect, minimal interventions were the preferred restoration strategy in wetlands. Changes in hydrology have been identified as one of the main causes of mangrove degradation . Therefore, to foster mangroves natural regeneration hydrological rehabilitation is implemented . Mangroves can regenerate naturally if the tidal hydrology has not been disrupted and if there are sufficient mangrove propagules nearby . Performing minimal cost-effective interventions such as hydrological rehabilitation, where degraded and destroyed channels are reconnected, can allow fast natural regeneration of mangroves [82,83]. For hydrological recovery, actions must target the same slope and elevation as the reference mangrove forest . Before deciding wetland ecosystem interventions, however, an environmental characterization and diagnosis of stressors causing its degradation are needed . The cost- effective ecological restoration of wetlands requires the recovery of hydrology and the identification of ecosystem factors stressors.
The need for transdisciplinary (not only multidisciplinary) approaches
Traditional management practices remain an undervalued source of knowledge for restoration. Our results indicate that top-down approaches are still common in restoration action and policies (decision-making). Some authors have indicated that Traditional Ecological Knowledge (TEK) is poorly applied in ecological restoration programs [17–19], including in several Latin American countries [60,85]. The participation of Indigenous Peoples and Local Communities (IPLCs) has been limited to the execution of actions (e.g., field labor) instead of co-designing restoration projects together with IPLCs that build on their TEK and experiences . It is also evident that TEK is still less considered in planning and monitoring  and that IPLCs are still absent in environmental policy forums at the country, regional and worldwide levels . In future restoration projects, incorporating TEK from IPLCs in the stages of planning, execution and monitoring will be fundamental for the recovery of ecosystems. Transdisciplinary research practices will likely be important in this context because they highlight the early involvement of non-academic actors in research projects, including ecological restoration projects. For instance, during the planning stage, IPLCs can supply reference ecosystem information. Similarly, IPLCs can inform about key species  and cultural places (e.g., food, medicine and foraging species) that make up the basis of a culture . They also might advise about particular places that are of critical importance for the flow of ecosystem services and way of life . During the execution of projects, IPLCs may contribute to (re)orienting the processes of ecosystem restoration. For instance, IPLCs have plenty of experience in the traditional management systems that can help or speed up succession [90–92]. Other TEK-based land management practices, like rotational swidden cultivation systems, agroforestry, fallow and culture improvement systems, hedgerow implementation, and living fences, have also been shown to be effective in carbon sequestration and fighting environmental degradation and desertification [93,94]. Finally, although the contribution of TEK to the progress of restoration is still insufficiently acknowledged, this source of knowledge can also be useful in designing and implementing restoration monitoring programs . Local communities often have a clear understanding of the factors that threaten their territory and cultures and thus can tell us a lot about which variables to measure . The application of TEK in ecological restoration can help inform site and species selection for restoration and provide historical information on ecosystem’s state (ecosystem reference) and land management.
Adequate planning for enhancing restoration success
Only a small fraction of projects that report ecological results (biodiversity) claimed to have achieved most of their planned goals. This result contrasts with the fact that more than 80% of the projects said to have defined their reference ecosystem . A restoration project will have better transparency, management capacity and chance of success if the ecological goals and objectives are clearly defined, can be easily measured, adequately evaluated, and planned based on a reference ecosystem . The lack of adequate planning for the accomplishment of the goals seems to be a generalized practice in Latin America [85,95], and reflects a lack of forethought about the factors that can influence the achievement of the goals, such as the depletion of funds [11,39] or socioeconomic reality. Similarly, it makes evident the deficiency in planning based on a clear theoretical framework to achieve short-, medium-, and long-term goals.
Evaluating the results of ecological restoration projects is not an easy task to achieve. This is because in some restoration projects the desired results can take several decades to become evident . In addition, post-disturbance ecosystems may have moved into alternate states . An, a priori diagnosis of the natural regeneration potential and identification of key factors that limit or determine the recovery of the ecosystem subject to intervention, however, is a fundamental step for obtaining satisfactory results [14,52], such as the recovery of biodiversity and associated ecosystem services [98,99]. These evaluations could be performed using low-cost and time-efficient indices or methodologies reported in the literature [64,100,101]. These evaluations, however, were apparently absent from the restoration projects. Scientists as well as land managers and the public might be able to assess initial ecosystems state using ecological indices in order to identify adequate restoration actions; see the Ecological Disturbance Index for tropical areas . This absence of initial evaluation, perhaps because of lack of technical capability or insufficient budgeting for developing baseline assessment as we found preciously , could explain the low levels of recovery of biodiversity and ecosystem services reported in the restoration projects. Having a clear understanding of the importance of adequate planning and initial evaluation would maximize the available funds and restoration results.
The success of restoration projects is not only a matter of ecological results. It is important to know whether projects lead to positive interactions among individuals. Despite the low levels of recovery of biodiversity and ecosystems services reported in most of the projects, positive interactions among local people were identified. This may be because individuals’ confidence in restoration activities is reinforced by the knowledge that others are also participating . This positive interaction among community members increases cooperative spirit and reduces project costs; rather than hiring people outside the restoration areas, community participation along with adequate technical training could lead to improved restoration results . Overall, social participation was adequate; however, this was limited to the field actions . Moreover, we previously found that field work, (i.e., implementation, monitoring and maintenance) is more frequently considered in the budget (74%) than desk work (50%; ). Restoration results would benefit from the inclusion of community members beginning at the decision-making and planning stages, and not just as the work force during the execution stage . Social involvement in steps other than field work is crucial for ecosystem recovery on a large scale.
In general, environmental services payments were not included in the restoration activities. This would be due to the uncertainty of the continuity of the project in the long term as a result of financial problems . For example, in the Mexican and Colombian national country-wide assessment of ecosystems restoration projects, 39 and 29 projects, respectively identified financial limitations [41,56] Moreover, environmental services payment has a limited efficacy in promoting restoration . Environmental services’ payment schemes are most efficient when efforts are directed to only one service, like carbon capture . This is usually a problem because most projects are multifunctional, and the actions are oriented toward biodiversity recovery.
An urgent need for monitoring the progress of ecological restoration
Although some monitoring protocols were established a priori, they were considered an extra cost of projects rather than a necessary investment. In Mexico, a previously analysis on the planning phase of restoration found that only 22 projects of 75, considered the monitoring in the budget . Insufficient budgeting for the monitoring phase may be due to the limited amount of money allocated to assess progress of restoration by governments that focus mostly or exclusively on implementation. Furthermore, the monitoring practices are usually not allowed in ecological restoration proposals . Monitoring is an essential component of recovery projects because of to their long-term nature . Monitoring enables the evaluation of restoration progress and informs subsequent management decisions and the adoption of corrective measures [108,109]. Information about monitoring is essential for land managers who need evidence-based evaluations to assess the achievement of restoration actions . Monitoring helps to verify whether specific endpoints have been reached, determine which restoration strategies are best suited for the recovery of a process, biodiversity, or an ecosystem service . In addition, the evaluation of restoration progress serves as a means for social learning . For example, besides of quantifying the number of hectares planted, monitoring can inform restoration practitioner about increases in forest cover [e.g., 32], or whether a recovered area is supplying the expected environmental and social benefits [113,114]. In the long term, monitoring helps to determine which species combinations can resist invasion and whether plant communities with complementary or redundant traits confer greater invasion resistance [115,116]. Monitoring protocols need to be carefully planned and be part of a project from its conception if they are to secure the long-term sustainability of restored areas.
According to our data, monitoring generally takes a top-down approach and is focused mostly on short-term ecological indicators. Local community members only rarely participated in monitoring or were the main responsible parties. National inventories of restoration in Colombia  and Peru , as well as the Latin American regional evaluation of integrated landscape initiatives , showed similar results in terms of community participation. Including IPLCs in a participatory monitoring scheme  can be useful for designing and implementing restoration monitoring programs . A recent study  showed that local people accurately collect data on forest change, drivers of change, threats to reforestation, and biophysical and socioeconomic impact. This valuable information might be difficult to obtain by other means. Several initiatives that included IPLCs in the monitoring of carbon capture are gaining importance because of the efforts of REDD + (Reducing Emissions from Deforestation and forest Degradation, +, as well as conservation and sustainable development) [e.g., 119,120]. In Mexico, through the Program for the Conservation of Species at Risk [PROCER; 121], IPLCs are involved in monitoring restored sites within natural protected areas. Although the incorporation of IPLCs in some monitoring processes is becoming more common , in most of the 75 projects that we evaluated, short-term ecological indicators were used in monitoring. Similar results are documented in Colombia, where 96% of the projects only monitored only short-term changes, such as the early survival and growth of planted seedlings, changes in plant ground cover, and erosion control . To date, 16 Latin American countries have committed to ecological restoration , but only four countries had developed national or subnational strategies by 2016 to implement their national restoration targets . Fulfilling those commitments and scaling up restoration actions will require the inclusion of IPLCs in restoration programs at all stages—from planning through implementation, through monitoring.
S1 Appendix. Survey used to collect the data.
We would like to thank Manuel Guariguata for his support during all phases of the project… We thank David Lam for constructive comments and Lynna Kiere an English native speaker, for helping revise the English version.
- 1. Zahawi RA, Reid JL, Holl KD. Hidden costs of passive restoration. Restoration Ecology. 2014;22(3):284–7.
- 2. Chazdon RL. Beyond deforestation: restoring forests and ecosystem services on degraded lands. Science. 2008;320(5882):1458. pmid:18556551
- 3. Guzmán-Luna A, Martínez-Garza C. Performance of 15 tropical tree species recruited or transplanted on restoration settings. Botanical Sciences. 2016;94(4):773.
- 4. Chazdon RL, Guariguata MR. Natural regeneration as a tool for large-scale forest restoration in the tropics: prospects and challenges. Biotropica. 2016;48(6):716–30.
- 5. Chazdon RL, Lindenmayer D, Guariguata MR, Crouzeilles R, Rey Benayas JM, Lazos Chavero E. Fostering natural forest regeneration on former agricultural land through economic and policy interventions. Environmental Research Letters. 2020;15(4):043002.
- 6. Shono K, Cadaweng EA, Durst PB. Application of assisted natural regeneration to restore degraded tropical forestlands. Restoration Ecology. 2007;15(4):620–6.
Ceccon E. Restauración en bosques tropicales: fundamentos ecológicos, prácticos y sociales. México: Ediciones Díaz de Santos/UNAM; 2013. 289 p.
Ganz D, Durst P, Dugan P, Mc Kenzie P. Assisted natural regeneration: an overview In: Dugan PC, Durst PB, Ganz DJ, McKenzie PJ, editors. Advancing assisted natural regeneration in Asia and the Pacific. Bangkok, Thailand: Food and agriculture organization of the united nations regional office for Asia and the Pacific 2003.
- 9. Paquette A, Hawryshyn J, Senikas AV, Potvin CJ. Enrichment planting in secondary forests: a promising clean development mechanism to increase terrestrial carbon sinks. Ecology and Society. 2009;14(1):31.
Martínez-Garza C, Osorio-Beristain M. Capítulo 17. Ocho años de restauración experimental en las selvas estacionales de México. In: Ceccon E, Martinez-Garza C, editors. Experiencias mexicanas en la restauración de los ecosistemas. Cuernavaca, Morelos, México: Universidad Nacional Autónoma de México, Centro Regional de Investigaciones Multidisciplinarias; Universidad Autónoma del Estado de Morelos; Ciudad de México, Comisión Nacional para el Conocimiento y Uso de la Biodiversidad; 2016. p. 385–406.
Rubens de Miranda B, Adeodato S. Economia da restauração florestal. São Paulo: The Nature Conservancy; 2017. 136 p.
- 12. Murcia C, Aronson J. Intelligent tinkering in ecological restoration. Restoration Ecology. 2014;22(3):279–83.
- 13. Clewell A, Rieger J, Munro J. Guidelines for developing and managing ecological restoration projects: Society for Ecological Restoaration; 2000. 8 p.
- 14. Gann GD, McDonald T, Walder B, Aronson J, Nelson CR, Jonson J, et al. International principles and standards for the practice of ecological restoration. Second edition. Restoration Ecology. 2019;27(S1):S1–S46.
- 15. Reyes‐García V, Fernández‐Llamazares Á, McElwee P, Molnár Z, Öllerer K, Wilson SJ, et al. The contributions of Indigenous Peoples and local communities to ecological restoration. Restoration Ecology. 2019;27:3–8.
- 16. Uprety Y, Asselin H, Bergeron Y, Doyon F, Boucher J-F. Contribution of traditional knowledge to ecological restoration: practices and applications. Ecoscience. 2012;19(3):225–37.
- 17. Robertson M, Nichols P, Horwitz P, Bradby K, MacKintosh D. Environmental narratives and the need for multiple perspectives to restore degraded landscapes in Australia. Ecosystem Health. 2000;6(2):119–33.
- 18. Mills M. Restoring the mauri of Oruarangi Creek. Water science and technology. 2003;48(7):129–37. pmid:14653643
- 19. Wehi PM, Lord JM. Importance of including cultural practices in ecological restoration. Conservation Biology. 2017;31(5):1109–18. pmid:28233353
- 20. Meli P, Herrera FF, Melo F, Pinto S, Aguirre N, Musálem K, et al. Four approaches to guide ecological restoration in Latin America. Restoration Ecology. 2017;25(2):156–63.
- 21. Lam DPM, Hinz E, Lang DJ, Tengö M, Wehrden Hv, B Martín-López. Indigenous and local knowledge in sustainability transformations research: a literature review. Ecology and Society. 2020;25(1):3.
- 22. Mijangos JL, Pacioni C, Spencer PBS, Craig MD. Contribution of genetics to ecological restoration. Molecular Ecology. 2015;24(1):22–37. pmid:25377524
- 23. Booth TH. Identifying particular areas for potential seed collections for restoration plantings under climate change. Ecological Management & Restoration. 2016;17(3):228–34.
- 24. Harrison PA, Vaillancourt RE, Harris R, Potts BM. Integrating climate change and habitat fragmentation to identify candidate seed sources for ecological restoration. Restoration Ecology. 2017;25(4):524–31.
- 25. Stanturf JA, Palik BJ, Dumroese RK. Contemporary forest restoration: a review emphasizing function. Forest Ecology and Management. 2014;331:292–323. http://dx.doi.org/10.1016/j.foreco.2014.07.029.
- 26. Vidal CY, Naves RP, Viani RA, Rodrigues RR. Assessment of the nursery species pool for restoring landscapes in southeastern Brazil. Restoration Ecology. 2020;28(2):427–34.
- 27. Laughlin DC. Applying trait-based models to achieve functional targets for theory-driven ecological restoration. Ecology Letters. 2014;17(7):771–84. pmid:24766299
- 28. M’Gonigle LK, Williams NM, Lonsdorf E, Kremen C. A tool for selecting plants when restoring habitat for pollinators. Conservation Letters. 2017;10(1):105–11.
Ceccon E, Varassin IG. Plant-pollinator interactions in ecosystems restoration. In: Benítez M, Miramontes O, Valiente-Baunet A, editors. Frontiers in ecology, evolution and complexity. México: EditoraC3, CopIt-arXives, Universidad Nacional Autónoma de México; 2014. p. 50–63.
- 30. Sinclair ARE, Pech RP, Fryxell JM, McCann K, Byrom AE, Savory CJ, et al. Predicting and assessing progress in the restoration of ecosystems. Conservation Letters. 2018;11(2):e12390.
- 31. Guariguata M, Evans K. A diagnostic for collaborative monitoring in forest landscape restoration. Restoration Ecology. 2019.
- 32. Le HD, Smith C, Herbohn J, Harrison S. More than just trees: assessing reforestation success in tropical developing countries. Journal of Rural Studies. 2012;28(1):5–19.
Murcia C, Guariguata MR, Montes E. Estado del monitoreo de la restauración ecológica en Colombia. In: M Aguilar-Garavito, Ramírez W, editors. Monitoreo a procesos de restauración ecológica aplicado a ecosistemas terrestres. Bogotá D.C., Colombia: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt (IAvH); 2015. p. 250.
- 34. Ruiz‐Jaen MC, Aide TM. Restoration success: how is it being measured? Restoration ecology. 2005;13(3):569–77.
- 35. Aronson J, Blignaut JN, Milton SJ, Le Maitre D, Esler KJ, Limouzin A, et al. Are socioeconomic benefits of restoration adequately quantified? A Meta‐analysis of recent papers (2000–2008) in Restoration Ecology and 12 other scientific journals. Restoration Ecology. 2010;18(2):143–54.
- 36. Suding KN. Toward an era of restoration in ecology: successes, failures, and opportunities ahead. Annual Review of Ecology, Evolution, and Systematics. 2011;42:465–87.
- 37. Wortley L, Hero JM, Howes M. Evaluating ecological restoration success: a review of the literature. Restoration Ecology. 2013;21(5):537–43.
- 38. Benayas J, Newton A, Diaz A, Bullock J. Enhancement of biodiversity and ecosystem services by ecological restoration: A Meta-Analysis. Science. 2009;325:1121–4. pmid:19644076
- 39. Evans K, Guariguata MR, Brancalion PH. Participatory monitoring to connect local and global priorities for forest restoration. Conservation Biology. 2018;32(3):525–34. pmid:29532979
Pela-Restauração-da-Mata-Atlântica-[PACTO]. Monitoring protocol for forest restoration programs & projects. São Paulo: LERF/ESALQ: Instituto BioAtlântica: Ministerio do Meio Ambiente; 2013. 59 p.
Murcia C, Guariguata MR. La restauración ecológica en Colombia: tendencias, necesidades y oportunidades. Documentos Ocasionales 107. Bogor, Indonesia: CIFOR; 2014. 107 p.
- 42. FAO. El estado de los bosques del mundo: las vías forestales hacia el desarrollo sostenible. Roma. Licencia: CC BY-NC-SA 3.0 IGO: Organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO); 2018.
- 43. CBD (Convention on Biological Diveristy). Aichi Biodiversity Targets 2016 [cited 2021 March 11]. Available from: https://www.cbd.int/sp/targets/.
Bonn Challenge. www.bonnchallenge.org 2020 [cited 2021 March 11]. Available from: www.bonnchallenge.org.
- 45. NYDF. New York Declaration on Forests. Progress Assessment Germany: Federal Ministry for Environment, Nature Conservation and Nuclear Safety; 2014 [cited 2021 March 11]. Available from: https://forestdeclaration.org/about.
United Nations Convention to Combat Desertification (UNCCD). Zero net land degradation. A sustainable development goal for Rio+20. Bonn, Germany: United Nations Convention to Combat Desertification; 2012. 6 p.
Initiative 20x20. 2014 [cited 2021 March 11]. Available from: http://www.wri.org/our-work/project/initiative-20x20/about-initiative-20x20#project-tabs.
- 48. United Nations (UN). Social Development Goals, Goal 15: Sustainably manage forests, combat desertification, halt and reverse land degradation, halt biodiversity loss. 2015 [Cited 2021 March 11]. Available from: https://www.un.org/sustainabledevelopment/sustainable-development-goals/.
- 49. Aronson J, Goodwin N, Orlando L, Eisenberg C, Cross AT. A world of possibilities: six restoration strategies to support the United Nation’s Decade on Ecosystem Restoration. Restoration Ecology. 2020;28(4):730–6.
- 50. United Nations (UN). UN Decade on ecosystem restoration 2021–2030: United Nations; 2020 [cited 2021 March 11]. Available from: https://www.decadeonrestoration.org/.
SER. Primer of the Society of Ecological Restoration. Tucson, Arizona, United States: Society for Ecological Restoration International Science & Policy Working Group 2004. 13 p.
McDonald T, Gann GD, Jonson J, Dixon KW. International standards for the practice of ecological restoration–including principles and key concepts. Washington, D.C.: Society for Ecological Restoration; 2016.
Stanturf J, Mansourian S, Kleine M, editors. Implementing forest landscape restoration. A Practitioner’s Guide. Vienna, Austria: International Union of Forest Research Organizations, Special Programme for Development of Capacities (IUFRO-SPDC); 2017.
- 54. Mansourian S, Vallauri D. Restoring Forest Landscapes: Important Lessons Learnt. Environmental Management. 2014;53(2):241–51. pmid:24310644
Gutiérrez MMT, Ayala BAM. Directorio mexicano de la conservación 2013. Ciudad de México: Fondo para la Comunicación y la Educación Ambiental, A.C.; 2013. 220 p.
Méndez-Toribio M, Martínez-Garza C, Ceccon E, Guariguata MR. La restauración de ecosistemas terrestres en México: Estado actual, necesidades y oportunidades. Bogor, Indonesia: Center for International Forestry Research (CIFOR); 2018. 99 p.
R-Core-Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/. 2019.
- 58. Chazdon RL. Beyond deforestation: restoring forests and ecosystem services on degraded lands. Science. 2008;320(5882):1458–60. pmid:18556551
- 59. Arroyo-Rodríguez V, Melo FPL, Martínez-Ramos M, Bongers F, Chazdon RL, Meave JA, et al. Multiple successional pathways in human-modified tropical landscapes: new insights from forest succession, forest fragmentation and landscape ecology research. Biological Reviews. 2015;92:326–40. pmid:26537849
- 60. Coppus R, Romijn E, Méndez-Toribio M, Murcia C, Thomas E, Guariguata RM, et al. What is out there? A typology of land restoration projects in Latin America and the Caribbean. Environmental Research Communications. 2019;1(4):041004.
- 61. Chazdon R, Lindenmayer D, Guariguata MR, Crouzeilles R, Benayas JMR, Chavero EL. Fostering natural forest regeneration on former agricultural land through economic and policy interventions. Environmental Research Letters. 2020;15:043002.
- 62. de Rezende CL, Uezu A, Scarano FR, Araujo DSD. Atlantic Forest spontaneous regeneration at landscape scale. Biodiversity and Conservation. 2015;24(9):2255–72.
- 63. Martínez-Garza C, Méndez-Toribio M, Ceccon E, Guariguata MR. Ecosystem restoration in Mexico: insights on the project planning phase. Botanical Sciences. 2021;99(2):242–56. https://doi.org/10.17129/botsci.2695.
- 64. Zermeño-Hernández I, Méndez-Toribio M, Siebe C, Benítez-Malvido J, Martínez-Ramos M. Ecological disturbance regimes caused by agricultural land uses and their effects on tropical forest regeneration. Applied Vegetation Science. 2015;18(3):443–55.
- 65. Guariguata MR, Ostertag R. Neotropical secondary forest succession: changes in structural and functional characteristics. Forest Ecology and Management. 2001;148(1–3):185–206. http://dx.doi.org/10.1016/S0378-1127(00)00535-1.
- 66. Latawiec AE, Crouzeilles R, Brancalion PHS, Rodrigues RR, Sansevero JB, Santos JSd, et al. Natural regeneration and biodiversity: a global meta-analysis and implications for spatial planning. Biotropica. 2016;48(6):844–55.
- 67. Crouzeilles R, Curran M, Ferreira MS, Lindenmayer DB, Grelle CEV, Rey Benayas JM. A global meta-analysis on the ecological drivers of forest restoration success. Nature Communications. 2016;7:11666 pmid:27193756
- 68. Holl KD. Restoring tropical forests from the bottom up. Science. 2017;355(6324):455–6. pmid:28154033
Initiative-20x20. Restoring 1 million hectares of degraded land in Mexico Washington, DC2020 [cited 2020 October 21]. Available from: https://initiative20x20.org/restoration-projects/restoring-1-million-hectares-degraded-land-mexico.
- 70. Vilà M, Weiner J. Are invasive plant species better competitors than native plant species?—evidence from pair-wise experiments. Oikos. 2004;105(2):229–38.
- 71. Hooper E, Condit R, Legendre P. Responses of 20 native tree species to reforestation strategies for abandoned farmland in Panama. Ecological Applications. 2002;12:1626–41.
- 72. Méndez-Toribio M, Benítez-Malvido J, Zermeño-Hernández IE, Castillo-Mandujano J. Removal of climbing plants and soil plowing as a strategy to enhance forest recovery in tropical dry forests old fields. Ecological Restoration. 2019;37(2):113–22.
Schnitzer S, Bongers F, Burnham R, J., Putz FE. Ecology of Lianas. Oxford, UK: John Wiley & Sons; 2015. 505 p.
Grime JP. Plant strategies, vegetation processes, and ecosystem properties: John Wiley & Sons Inc; 2002. 456 p.
- 75. Pierce S, Negreiros D, Cerabolini BE, Kattge J, Diaz S, Kleyer M, et al. A global method for calculating plant CSR ecological strategies applied across biomes world‐wide. Functional Ecology. 2016;31: 444–57. https://doi.org/10.1111/1365-2435.12722.
- 76. Holling CS. Resilience and stability of ecological systems. Annual Review of Ecology and Systematics. 1973;4:1–23.
- 77. Suding KN, Gross KL, Houseman GR. Alternative states and positive feedbacks in restoration ecology. Trends in Ecology & Evolution. 2004;148(1):29–42. pmid:16701225
- 78. Didham RK, Watts CH, Norton DA. Are systems with strong underlying abiotic regimes more likely to exhibit alternative stable states? Oikos. 2005;110(2):409–16.
- 79. Turner R, Lewis R. Hydrologic restoration of coastal wetlands. Wetlands Ecology and Management. 1996;4:65–72.
- 80. Pérez-Ceballos R, Zaldívar-Jiménez A, Canales-Delgadillo J, López-Adame H, López-Portillo J, Merino-Ibarra M. Determining hydrological flow paths to enhance restoration in impaired mangrove wetlands. PLoS ONE. 2020;15(1):e0227665. pmid:31999717
- 81. Ellison AM. Mangrove restoration: do we know enough? Restoration Ecology. 2000;8(3):219–29.
- 82. Brockmeyer R, Rey J, Virnstein R, Gilmore R, Earnest L. Rehabilitation of impounded estuarine wetlands by hydrologic reconnection to the Indian River Lagoon, Florida (USA). Wetlands Ecology and Management. 1996;4(2):93–109.
- 83. Teutli-Hernández C, Herrera-Silveira J, Ceccon Y, Martínez-Garza C. Estrategias de restauración de manglares de México: el caso Yucatán. Experiencias mexicanas en la restauración ecológica de ecosistemas Cuernavaca: CONABIO, CRIM-UNAM, UAEM. 2016:459–84.
- 84. Zaldívar-Jiménez MA, Herrera-Silveira JA, Teutli-Hernández C, Comín FA, Andrade JL, Molina CC, et al. Conceptual framework for mangrove restoration in the Yucatán Peninsula. Ecological Restoration. 2010;28(3):333–42.
- 85. Murcia C, Guariguata MR, Andrade Á, Andrade GI, Aronson J, Escobar EM, et al. Challenges and prospects for scaling‐up ecological restoration to meet international commitments: Colombia as a case study. Conservation Letters. 2016;9(3):213–20.
- 86. Ceccon E, Mendez-Toribio M, Martínez-Garza C, Guariguata MR. Social participation in forest restoration projects: Insights from a national assessment in Mexico. Human Ecology. 2020;48:609–17. https://doi.org/10.1007/s10745-020-00178-w.
- 87. Fremout T, Gutierrez Miranda C, Briers S, Marcelo Peña JL, Cueva Ortiz E, Linares-Palomino R, et al. The value of local ecological knowledge to guide tree species selection in tropical dry forest restoration. Restoration Ecology. 2021.
- 88. Garibaldi A, Turner N. Cultural keystone species: implications for ecological conservation and restoration. Ecology and Society. 2004;9(3).
- 89. Cuerrier A, Turner NJ, Gomes TC, Garibaldi A, Downing A. Cultural keystone places: conservation and restoration in cultural landscapes. Journal of Ethnobiology. 2015;35(3):427–49.
- 90. Anderson MK, Barbour MG. Simulated indigenous management: a new model for ecological restoration in national parks. Ecological Restoration. 2003;21(4):269–77.
- 91. Diemont SA, Martin JF. Lacandon Maya ecosystem management: Sustainable design for subsistence and environmental restoration. Ecological Applications. 2009;19(1):254–66. pmid:19323187
- 92. Douterlungne D, Levy‐Tacher SI, Golicher DJ, Dañobeytia FR. Applying indigenous knowledge to the restoration of degraded tropical rain forest clearings dominated by bracken fern. Restoration Ecology. 2010;18(3):322–9.
- 93. Wangpakapattanawong P, Kavinchan N, Vaidhayakarn C, Schmidt-Vogt D, Elliott S. Fallow to forest: Applying indigenous and scientific knowledge of swidden cultivation to tropical forest restoration. Forest Ecology and Management. 2010;260(8):1399–406.
- 94. Coughlan MR. Farmers, flames, and forests: Historical ecology of pastoral fire use and landscape change in the French Western Pyrenees, 1830–2011. Forest Ecology and Management. 2014;312:55–66.
Murcia C, Guariguata MR, Peralvo M, Gálmez V. La restauración de bosques andinos tropicales: Avances, desafíos y perspectivas del futuro. Bogor, Indonesia: Center for International Forestry Research (CIFOR); 2017. 96 p.
- 96. Moreno-Mateos D, Power ME, Comín FA, Yockteng R. Structural and functional loss in restored wetland ecosystems. PLoS Biology. 2012;10(1):e1001247. pmid:22291572
- 97. Cortina J, Maestre FT, Vallejo R, Baeza MJ, Valdecantos A, Pérez-Devesa M. Ecosystem structure, function, and restoration success: are they related? Journal for Nature Conservation. 2006;14(3–4):152–60.
- 98. Pistorius T, Carodenuto S, Wathum G. Implementing forest landscape restoration in Ethiopia. Forests. 2017;8(3). WOS:000398711600010.
Chazdon RL, Guariguata MR. Decision support tools for forest landscape restoration: Current status and future outlook. Bogor, Indonesia: Center for International Forestry Research (CIFOR); 2018. 58 p.
- 100. Jansen A, Alistar R. Relationship between livestock management and ecological condition of riparian habitats along an Australian floodplain river. Journal of Applied Ecology. 2001;38:63–75.
- 101. Martorell C, Peters EM. The measurement of chronic disturbance and its effects on the threatened cactus Mammillaria pectinifera. Biological Conservation. 2005;124(2):199–207.
Bourdieu P. The forms of capital. In: Granovetter M, Swedberg R, editors. The sociology of economic life. Third edition ed. New York: Routledge; 2011. p. 241–58.
- 103. Meli P, Schweizer D, Brancalion PH, Murcia C, Guariguata MR. Multi‐dimensional training among Latin America’s restoration professionals. Restoration Ecology. 2019;27:477–84.
- 104. Bullock JM, Aronson J, Newton AC, Pywell RF, Rey-Benayas JM. Restoration of ecosystem services and biodiversity: Conflicts and opportunities. Trends in Ecology & Evolution. 2011;26(10):541–9. pmid:21782273
- 105. Pirard R, de Buren G, Lapeyre R. Do PES improve the governance of forest restoration? Forests. 2014;5(3):404–24.
- 106. Wunder S, Engel S, Pagiola S. Taking stock: A comparative analysis of payments for environmental services programs in developed and developing countries. Ecological Economics. 2008;65(4):834–52.
Holl KD, Cairns J. Monitoring and appraisal. In: Perrow MR, Davy AJ, editors. Handbook of ecological restoration. 1. New York: Cambridge University Press; 2002. p. 411–32.
Shabman LA. Making watershed restoration happen: what does economics offer? In: Cairns J Jr, editor. Rehabilitating damaged ecosystems. Boca Raton, Florida: CRC Press; 1995. p. 35–47.
Spaeth A, Horning D, Blevins B, Edwards SR. Understanding social processes in planning ecological restorations. In: Allison SK, editor. Routledge handbook of ecological and environmental restoration: Routledge; 2017. p. 49–65.
- 110. Palmer MA, Filoso S. Restoration of ecosystem services for environmental markets. Science. 2009;325(5940):575–6. pmid:19644112
- 111. Dey DC, Schweitzer CJ. Restoration for the future: endpoints, targets, and indicators of progress and success. Journal of Sustainable Forestry. 2014;33(sup1):S43–S65.
- 112. DellaSala D, Martin A, Spivak R, Schulke T, Bird B, Criley M, et al. A citizen’s call for ecological forest restoration: Forest restoration principles and criteria. Ecological Restoration. 2003;21(1):15.
Moreno-Calles AI, Casas A, Toledo VM, Vallejo-Ramos M. Etnoagroforestería en México. México, Distrito Federal: Universidad Nacional Autónoma de México, Escuela Nacional de Estudios Superiores Unidad Morelia, Instituto de Investigaciones en Ecosistemas y Sustentabilidad; 2016. 349 p.
- 114. Mansourian S, Dudley N, Vallauri D. Forest landscape restoration: Progress in the last decade and remaining challenges. Ecological Restoration. 2017;35(4):281–8.
- 115. Ostertag R, Cordell S, Michaud J, Cole TC, Schulten JR, Publico KM, et al. Ecosystem and restoration consequences of invasive woody species removal in Hawaiian lowland wet forest. Ecosystems. 2009;12(3):503–15.
- 116. Ostertag R, Warman L, Cordell S, Vitousek PM. Using plant functional traits to restore Hawaiian rainforest. Journal of Applied Ecology. 2015;52(4):805–9.
Cerrón J, Castillo Jd, Mathez-Stiefel S-L, Thomas E. Lecciones aprendidas de experiencias de restauración en el Perú. Bioversity International; World Agroforestry Centre (ICRAF); SERFOR; 2017.
- 118. Estrada-Carmona N, Hart AK, DeClerck FAJ, Harvey CA, Milder JC. Integrated landscape management for agriculture, rural livelihoods, and ecosystem conservation: An assessment of experience from Latin America and the Caribbean. Landscape and Urban Planning. 2014;129:1–11. https://doi.org/10.1016/j.landurbplan.2014.05.001.
- 119. Hartoyo APP, Siregar IZ, Prasetyo LB, Thelaide I. Biodiversity, carbon stocks and community monitoring in traditional agroforestry practices: Preliminary results from two investigated villages in Berau, East Kalimantan. Procedia Environmental Sciences. 2016;33:376–85.
- 120. McCall MK, Chutz N, Skutsch M. Moving from measuring, reporting, verification (MRV) of forest carbon to community mapping, measuring, monitoring (MMM): perspectives from Mexico. PloS one. 2016;11(6):e0146038. pmid:27300439
PROCER. Términos de referencia de los conceptos de apoyo de la Convocatoria para solicitar apoyos ejecución de actividades del programa de recuperación y repoblación de especies en riesgo (PROCER). Ciudad de México: Comisión Nacional de Áreas Naturales Protegidas (CONANP); 2019.
- 122. Méndez-Toribio M, Martínez-Garza C, Ceccon E, Guariguata MR. Planes actuales de restauración ecológica en Latinoamérica: avances y omisiones. Current ecological restoration plans in Latin America: progress and omissions. Revista de Ciencias Ambientales (Trop J Environ Sci). 2017;51(2):1–30.