Fig 1.
Mean species accumulation of four taxon groups by 0.5-h survey intervals in Estonian swamp forests.
Data for the 2-ha plots in 10 old stands and 10 post-clearcut stands are shown separately; the whiskers are 95% CI. Note the overlapping curves of vascular plants and bryophytes in forests, but their opposite responses to clear-cutting (right).
Table 1.
Overview of the material collected using the fixed-area-fixed-effort survey method in Europe and South America: taxon groups, field designs, and published reports.
Fig 2.
Species accumulation during 4-hour polypore surveys in 2-ha plots in different ecosystems.
(A) Highly productive old growth forests in two biomes; (B) pre-harvest vs. post-harvest mixedwood stands in Estonian production forests (same site types as the hemiboreal old-growth in A); (C) Scots pine dominated mature stands on Podzols (dry boreal sites) vs. drained mixotrophic peat in Estonia. The points show arithmetic means (±SD); numbers in parentheses are sample sizes. S1 Fig illustrates the ecosystems.
Fig 3.
Track records of three observers using the survey protocol for four taxon groups based on >110 surveys each.
(A–B) Polypores (two different observers); (C–D) lichens and bryophytes (the same observer). Linear regression (±95 CI) between the survey order and recorded species richness (y-axis, standardized by forest type) indicates a ‘learning effect’ and is statistically significant only in (A): slope 0.029 ± 0.011, P < 0.01.
Fig 4.
Polypore species accumulation in 2-ha plots in two repeatedly surveyed old-growth forests in East Estonia: along with survey time (A) and in subsequent surveys, 2005–2016 (B). The horizontal lines denote numbers of species found in the plots during many casual mycological surveys between the 1930s and 2004 [53]. In (A), the symbols denote arithmetic means (±S.D.); in the rarefaction analysis (B), the symbols are expected numbers, S(est) ±95% CI, in the pooled sample.
Fig 5.
Survey-based rarefaction curves for polypore species richness in old (N= 97) and clear-cut (N=46) Estonian forests compared with the known national species pool in the surveyed forest types (black area; increasing due to 13 species added by these surveys).
The curve lines denote expected numbers of species in pooled samples (S(est)) ± 95% CI; the grey area depicts a similar rarefaction for forests and clear-cuts pooled.
Fig 6.
Time to detection of the polypore Rigidoporus crocatus in relation to its total number of records.
The data are from 53 2-ha plots in Estonia where the species was detected during the 4-h surveys; no. of records refers to fallen trunks with fruit bodies found during the 4 h. The line depicts linear regression (± 95% CI; P < 0.001).
Fig 7.
Polypore surveys in nine Neotropical terra firma forest sites in French Guiana over a gradient of human disturbance.
(A) Location of the nine sample plots; (B) their mean species accumulation curves; (C) non-metric multidimensional scaling ordination of the assemblages (% variance explained on axis). (Right panel) The ecosystems studied: a, old growth (4 plots) and, b, selectively logged forests (2 plots); naturally regenerated slash-and-burn agriculture sites with (c) partial retention of forest legacies (2 plots) and, d, after soil scarification (1 plot). Note that (B) suggests impoverishment of treatment (d) only, but assemblage composition reveals opposite shifts after logging vs. slash-and-burn.