Liana: the stalking strangler?
MetadataShow full item record
CTA. 2002. Liana: the stalking strangler?. Spore 101. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/47707
Internet URL: http://spore.cta.int/images/stories/pdf/old/spore101.pdf
Best known as Tarzan s preferred means of transport, the twine-like liana may have a negative impact on its rainforest habitat. The role of lianas in forest ecologies has long been underestimated, and these climbing jungle weeds were for long...
Best known as Tarzan s preferred means of transport, the twine-like liana may have a negative impact on its rainforest habitat. The role of lianas in forest ecologies has long been underestimated, and these climbing jungle weeds were for long regarded literally as loose ends. Wrongly so, since they constitute about 25% of the wood density and plant diversity in tropical forests. In the past decade, researchers worldwide have swung to liana as a research topic: universities in Basel, Leeds and Wageningen in Europe, and in the states of Massachusetts and Minnesota in the USA are among those to have launched research programmes. Their findings are not entirely in lianas favour. Liana are useful as a source of wood, as medicinal plants and for providing canopy-to-canopy access for forest animals by physically linking trees. They also affect tree regeneration, however competing with trees and affecting how trees compete among themselves for light, water and nutrients. In that respect, they behave like weeds in agriculture and can be considered pioneer plants. In forests where loggers are active, the density of lianas can be twice as much as in unlogged pristine forests. In recent years, in the western Amazon region, the density of lianas has nearly doubled, damaging and killing established trees and blocking out the sunlight. In the gaps left behind, thinner foliage has shot up, leaving the forest with far less biomass than before the lianas explosive growth. The researchers have evidence that lianas are growing faster in today s carbon dioxide (CO2) levels than the lower levels a century ago. The fact that rainforests are regarded as carbon sinks, absorbing CO2 from the air and transforming it into wood, might give rise to a fierce debate if it means that forests are being killed by the same lianas they host. Like so many others faced with the environmental impact of their mode of transport, even poor old Tarzan may have to get on his bike. [caption to illustration] Mother Nature s network to some, but a damn nuisance to nature