Outlook on climate change adaptation in the Tropical Andes mountains

predicts a reduction of evergreen forests, in favour of more seasonally dry forests. However, the predicted rate of warming requires forests to migrate by more than 9m in altitude per year (Feeley and Silman, 2010). This is much lower than observed migration rates and it is likely that most species will lose substantial proportions of their population. Variance in ability to migrate partly determines the implications of climate change on species and ecosystems. Cloud forests, for example, have been unable to migrate into the high grasslands while being diminished in lower elevations (Rehm and Feeley, 2015). Features of both species themselves and their environment can limit migration. For instance, insurmountable peaks and steep valleys represent migration borders. Land use can also reduce the ability for tropical mountain forests to migrate. Studies show faster upward migration in protected than in non-protected areas (Lutz et al., 2013). However, the rate of migration is still too slow to match the predicted changes in climate. Lakes and rivers The aquatic ecosystems of the Tropical Andes include a great number of lakes, rivers and wetlands occupied by fish, microinvertebrates, plankton, algae and plants. The diversity of fish species declines with altitude, while algae and aquatic plants show the greatest diversity above 3,000 m (Maldonado et al., 2011). Lake Titicaca, with its numerous endemic species of fish, plants and algae, is an exception.The highly vulnerable aquatic ecosystems could be an early indicator of climate change in the region. However, few studies exist on the topic. Studies from Europe suggest a substantial decrease of cold-water species in favour of more warm-water species. Rivers and lakes depending on water from vulnerable areas such as páramos and glaciers could experience the largest impact.

Lake Titicaca

Lake Titicaca – Cooler as it becomes drier?

Tropical mountain forests With warmer temperatures, ecosystems often respond by moving upslope to colder climates (Feeley and Silman, 2010). This trend has been observed for Adaptation policies must be designed to acknowledge the local variation in both hazards from climate change, and the vulnerabilities of local people and ecosystems. Lake Titicaca is the largest lake in South America in terms of volume. Due to its size and depth, it has a substantial effect on the local climate. The immediate areas around the lake today are about 4-5°C warmer and are also wetter than comparable areas at the same altitude. Palaeological records have shown that as water levels of the lake lowered during warm, dry, interglacial periods, a regional cooling effect took place and even reversed the trend

towards warming. In a warming world, species are generally expected to migrate upward in order to stay within their optimal temperature range. This has already been observed on tropical mountains (Feeley et al., 2011). However, Lake Titicaca may be an example where such general assumptions do not apply and where the upward migration of forests will be halted abruptly (Bush et al., 2010). However, a reduced Lake Titicaca would have a huge impact on irrigation and agriculture downstream and Lake Titicaca has an impact on the whole endorreic (closed drainage system) Titicaca-Desaguadero-Poopó-Salares watershed. decades as some species of trees are attempting to out- climb the heat (Feeley et al., 2011).The aforementioned biome-based model predicts that areas currently covered by páramos will become suited to tropical mountain forests (Tovar et al., 2013). The model also

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