Epiphytes in human settlements in rural Panama

Abstract

<p><b><i>Background</i>:</b> An ever-increasing proportion of tropical ecosystems are affected by on-going land-use changes, stressing the importance of understanding how organisms cope with biotic and abiotic challenges outside their natural habitat. An important group in the tropics are vascular epiphytes, whose response to human disturbance is poorly understood.</p> <p><b><i>Aims</i>:</b> Creating a baseline data set of epiphyte diversity in human settlements and assessing differences with assemblages of less disturbed habitats.</p> <p><b><i>Methods</i>:</b> We surveyed the vascular epiphyte assemblages in 25 settlements of south-west Panama along a rainfall gradient. We tested how epiphyte assemblages were affected by human disturbance and climate by comparing our data to that of pastures and forest.</p> <p><b><i>Results</i>:</b> Almost half (238 of 499) of all studied trees hosted at least one epiphyte. Altogether, 10,700 epiphytes of 56 species were found. Rainfall strongly affected both composition and diversity of epiphyte assemblages, whereas geographic proximity did not. In settlements, the species pool was considerably smaller than in pastures and undisturbed forest; however, settlements’ diversity was only significantly lower compared to pastures.</p> <p><b><i>Conclusions</i>:</b> Epiphyte assemblages in settlements had a diminished species pool but diversity per tree was comparable to less disturbed habitats. Unsurprisingly, rainfall seems to be the main determinant of epiphyte diversity in rural settlements.</p