Trees, due to their large biomass, play a crucial role in many ecosystems by influencing ecosystem processes. Our understanding of the patterns of plant diversity in tropical forests and their responses to fragmentation are mostly based on tree surveys. But are these patterns and responses representative of other plant life-forms? Studies of multiple plant life-forms provide a more robust understanding of fragmentation impacts on plant communities, but they are rare.
Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) compared patterns of species composition, diversity, and density, for trees, lianas, herbs, and ferns in 48 permanent sampling plots across a fragmented forest landscape in Xishuangbanna, SW China.
They asked whether it is reasonable to rely on tree data to understand patterns of total plant diversity in tropical forests and whether tree data can be used to understand total plant community responses to forest fragmentation.
They found that once community type had been accounted for, tree species richness was a good predictor of herb and fern richness, but a poor predictor of liana richness. Tree density could not predict the density of the other life-forms.
Tree responses to fragmentation were also mostly poorly representative of responses of other life-forms to fragmentation, as only tree composition and density were related to fragmentation whereas richness of lianas and herbs were also responding to fragmentation.
Thus the effects of fragmentation on forest vegetation cannot be understood through tree responses alone.
Moreover, measuring fragmentation at the community level may be critical to detect and understand the effects of fragmentation across forest landscapes, suggesting it is first necessary to identify distinct communities within local landscapes. The study entitled “Trees represent community composition of other plant life-forms, but not their diversity, abundance or responses to fragmentation” has been published in Scientific Reports.