Department of Environmental Sciences, Centre for Ecosystem Studies, Wageningen University, 6708 PB Wageningen, NETHERLANDS.
Lianas (woody climbers) and trees are the most important life-forms in most tropical forests. In many of these forests lianas are abundant and diverse and their presence is often a key physiognomic feature. Lianas contribute substantially to the floristic, structural and functional diversity of tropical forests, and have both positive (providing valuable food resources, habitat, and connections among tree canopies that are used as pathways by arboreal animals) and negative (reducing tree growth, fecundity and survivorship) effects on forests.
Lianas are increasingly well studied in many areas around the world, but in southeast Asia they are relatively unknown. This PhD dissertation describes liana communities in selected but well distributed tropical forests in Xhishuangbanna, southwest China. In addition the question what makes lianas functionally different from trees is addressed. A number of structural-functional characteristics of lianas are analysed, comparative to trees. Special attention is put to growth performance and ecophysiological leaf and plant characters in a framework of adaptive ecology. The last part of the dissertation addresses adaptive behavior, both within one liana species as across a number of species differing in adult stature.
It is clear that lianas have growth strategies different from trees, as shown for some aspects in this thesis, but lianas do not always follow expected patterns. Additionally, for some characteristics lianas are far less different from trees than expected, as has been showed by a number of recent studies (Gilbert et al. 2006, Santiago and Wright 2007, Selaya 2007, this thesis). These new results shed new light on patterns of adaptive ecology of lianas versus trees in tropical forests. Together, these results force us to re-evaluate the broad generalizations that we sometimes use. This warrants further studies on the ecological differences between lianas and trees, including variations therein among forest types in different climates.