Eric A. Graham, Mark H. Hansen, William J. Kaiser, Yeung Lam, Philip W. Rundel, Michael J. Stealey, and Eric M. Yuen. University of California, Los Angeles
Landscapes are becoming increasingly fragmented due to human activities and research into how edges affect vegetation has become more important. Many descriptive studies of microclimate changing across sharp transition zones exist in the literature and much attention has been focused on modeling edge dynamics. Fine-scale temporal dynamics of microclimate have been mostly ignored, however, in favor of larger time-scale measurements. Moving boundaries and areas of influence of microclimate pose important challenges to not only statistical research but also sampling regimes in order to capture the dynamic aspect of forest edges. We measured microclimatic variables across an old, sharp edge from a clearing into primary lowland tropical rainforest at La Selva Biological Station in Costa Rica. Each of three transects, approximately 30 m in length, was measured at every meter sequentially for 24 h with a mobile sensor platform supported by a cable infrastructure. Penetration into the forest of air temperature, relative humidity, photosynthetically active radiation, and effective surface temperature differences is modeled using piece-wise linear, logistic, and piece-wise double exponential models for comparisons.
