Chronic harvesting threatens tropical tree

Aug 05, 2013

Chronic harvesting of a tropical tree that many local communities in Western Africa depend on can alter the tree's reproduction and drastically curtail fruit and seed yields over the tree's lifetime, according to a new study.

The study, which appears today in the Journal of Ecology, is the first of its kind to use what's called "age-from-stage" mathematical modeling, a way of estimating plant age from its size, to investigate how harvesting affects a plant's life expectancy and other life history traits, such as age at maturity.

In this case, the tree Khaya senegalensis, commonly known as African mahogany, is found in many habitats in Western Africa, from forests to savanna woodland, and is considered a due to drought and logging. The tree is heavily harvested for its leaves, to feed cattle, and for its bark, which is used medicinally to treat many ailments, from to reducing malaria fevers.

Specifically analyzing harvesting effects on the tree in both dry and moist regions in Benin, the study found that plant harvesting affects life history in different ways depending on the climatic conditions. In the moist region, chronic harvest delayed reproduction and the trees lived longer, whereas in the dry region, chronic harvesting hastened reproduction and shortened the tree's life span.

"For who are harvesting these plants, knowing how long a particular species is going to persist or how soon it is going to reproduce is valuable information for planning and management, especially for plants for which fruits are harvested," said Orou Gaoue, the study's lead author and assistant professor of ecology, evolution and at the University of Hawaii at Manoa.

"As we consider how global warming may affect human livelihood and the resources we use, it is important to understand and account for the ways in which variation in climate and human behavior can change the traits or productivity of harvested ," Gaoue added. "Here we found that if you fail to account for that variability, even in harvesters' behavior, you may underestimate the effect of harvesting on population life history traits."

Explore further: Giant anteaters kill two hunters in Brazil

More information: Gaoue OG, Horvitz CC, Ticktin T, Steiner UK, Tuljapurkar S. 2013. Defoliaton and bark harvesting affect life history traits of a tropical tree. Journal of Ecology

add to favorites email to friend print save as pdf

Related Stories

The Sahara olive tree: A genetic heritage to be preserved

May 03, 2013

The Saharan cousin of Mediterranean olive trees remains largely unknown. However, this subspecies (called the Laperinne's olive tree) is of great interest for several reasons. IRD researchers and their partners ...

Recommended for you

Seeds keep vital much longer when stored without oxygen

19 hours ago

If seed breeding companies, gene banks and the Svalbard Global Seed Vault on Spitsbergen should store plant seeds under oxygen-poor conditions, it would be possible to store them for much longer while still ...

Native species may be hindering fox control efforts

19 hours ago

Native species interfering with ground distributed baits used to control red foxes in south west Western Australia may mean the baits are not available to the target species, a Murdoch University study has ...

Giant anteaters kill two hunters in Brazil

Jul 26, 2014

Giant anteaters in Brazil have killed two hunters in separate incidents, raising concerns about the animals' loss of habitat and the growing risk of dangerous encounters with people, researchers said.

User comments : 0