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: Effects of interannual climate variability on tropical tree cover

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

Ranchers benefit from long-term grazing data

23 minutes ago

Scientists studying changes in the Earth's surface rely on 40 years of Landsat satellite imaging, but South Dakota ranchers making decisions about grazing their livestock can benefit from 70 years of data ...

Diverse gene pool critical for tigers' survival

1 hour ago

(Phys.org) —New research by Stanford scholars shows that increasing genetic diversity among the 3,000 or so tigers left on the planet is the key to their survival as a species.

User comments : 0

More news stories

Ranchers benefit from long-term grazing data

Scientists studying changes in the Earth's surface rely on 40 years of Landsat satellite imaging, but South Dakota ranchers making decisions about grazing their livestock can benefit from 70 years of data ...

Melting during cooling period

(Phys.org) —A University of Maine research team says stratification of the North Atlantic Ocean contributed to summer warming and glacial melting in Scotland during the period recognized for abrupt cooling ...