Rains are back, and we hardly remember how dry it was a couple of weeks ago. Usually, we do not associate moist tropical forests with drought, but during the ‘verano' it gets astonishingly dry in most Panamanian lowland forests, just as in many tropical forests worldwide: Plants suffer from drought, they grow slower, wilt and even die.

credit: STRI

Droughts are predicted to increase in intensity and frequency in the tropics. Understanding their importance is essential for projecting consequences of global climate change for tropical forests.

Panama is an ideal site to study the importance of drought for plant populations and communities because the forests across the Isthmus span an extreme rainfall gradient from the dry Pacific side to the wet Carribean side, and deep data sets are available on tree distribution and long-term rainfall patterns from CTFS and the Panama Canal Authority.

Bettina Engelbrecht, STRI research associate from the University of Kaiserslautern and collaborators have recently shown that drought shapes tree species distributions in tropical forests at the local and regional scale.

Funded by the German Science Foundation (DFG) she conducts seedling transplant experiments across the Isthmus to investigate in more detail how seedling regeneration translates into species distribution patterns, and if indeed seedling performance is higher in areas were a species occurs than outside its distribution …and that work does not stop with the rains.

Source: STRI