Disrupted Ecosystems XXI: Monte Verde Cloud Forest, Costa Rica, 2006

Monteverde Reserve: photographed April 2006.

Per its vulnerability to the climate change, the following is from the IPCC: “The tropical cloud forests in mountainous regions will be threatened if temperatures increase by 1°C to 2°C during the next 50 years due to changes in the altitude of the cloud-base during the dry season, which would be rising by 2 m/yr.  In places with low elevation and isolated mountains, some plants will become locally extinct because the elevation range would not permit natural adaptation to temperature increase (FAO, 2002).  The change in temperature and cloud-base in these forests could have substantial effects on the diversity and composition of species.  For example, in the cloud forest of Monteverde Costa Rica, these changes are already happening.  Declines in the frequency of mist days have been strongly associated with a decrease in population of amphibians (20 of 50 species) and probably also bird and reptile populations (Pounds et al., 1999)” (IPCC, AR4 WGII, Chapter 13 p.596).  Note that the role climate in the extinction of the golden toad has been questioned by a 2010 study.

Per the impact that warming in the cloud forest may have on the climate by way of feedbacks:  Data gathered by Drs. Deborah and David Clark over the past 20 years in a Costa Rican rain forest indicates that rising temperatures are causing tropical forests to grow more slowly and if temperatures cross a certain yet unknown threshold, could start to decay.  (As temperatures rise, land plants release, rather than absorb, CO2 as their metabolism slows photosynthesis, which reduces their growth and increases respiration.)  This process could cause tropical forests to become sources of atmospheric CO2 rather than net reducers, significantly impacting the world’s climate.