Figure 1.
Current (observed) biome map (A) based on the Andean Ecological Systems Map [27], modelled potential biome map for the present 2000 (B) and an example of future biome map (C) using climatic variables of model gfdl_cm2_0 for A1B 2040–2069 scenario.
Table 1.
Tropical Andean biomes, characteristic plant life-form and ordinal ranking based on humidity levels (from less humid to more humid) for each biome.
Table 2.
Accuracy assessment of the modelled potential biome map for the present (thousands of pixels).
Figure 2.
Elevational range changes for A1B 2040–2069.
Glaciers and cryoturbated areas, paramo, humid puna and evergreen montane forest show upward displacement of the lower boundary. This can be observed in the left hand side of the accumulation curves, where curves of all models for the future (in grey) are higher than the curves for the present (dotted line). Seasonally dry tropical montane forest, montane shrubland and xeric pre-puna show downslope expansion in the lower boundary where future curves are lower than the present one. Upper boundary show upward displacement for almost all biomes, observed at the right hand side of the accumulation curves. The x-values were scaled from 0 to 1 to compare landscapes of different size.
Figure 3.
Median change in the area of potential biomes versus remnant biomes for A1B scenario period 2010–2039 and 2040–2069.
In dark grey the lost areas (the biome will be replaced by another biome), in grey stable areas (areas that remained unchanged) and in light grey new or emerging areas (the biome is projected to occur in the future but not in the present). Black lines represent the minimum and maximum values of all models. The sum of the stable and lost areas represent the present area, while the sum of the stable and emerging areas represent the future projected area.
Table 3.
Conversion matrix of biomes from present to future.
Figure 4.
Agreement on the direction of the projected change between biome models using different climatic models.
Calculations were made for scenario A1B 2010–2039 (A), A2 2010–2039 (B), A1B 2040–2069 (C) and A2 2040–2069 (D) based on physiognomy (desert, grassland, shrubland, forest) or humidity level. +++ Increasing vertical structure, ++ Either increasing vertical structure or humidity level, + Increasing humidity level, stable physiognomy, - Decreasing humidity level, stable physiognomy, -- Either decreasing vertical structure or humidity level, --- Decreasing vertical structure. Areas where less than 7 models agree on the direction of change are considered under the class “disagreement”.
Table 4.
Percentage of the present Andean area where more than 80% of the models (at least 7) agree on the direction of the change in physiognomy (desert, shrubland, grassland, forest) and/or humidity levels.