Drough threatens forests

 

 

Forests worldwide threatened by drought

Date:
February 21, 2017
Source:
University of Stirling
Summary:
Forests around the world are at risk of death due to widespread drought, researchers have found. An analysis suggests that forests are at risk globally from the increased frequency and severity of droughts.

An analysis, published in the journal Ecology Letters, suggests that forests are at risk globally from the increased frequency and severity of droughts.

The study found a similar response in trees across the world, where death increases consistently with increases in drought severity.

Dr Sarah Greenwood, Postdoctoral Researcher in Stirling’s Faculty of Natural Sciences, said: “We can see that the death of trees caused by drought is consistent across different environments around the world. So, a thirsty tree growing in a tropical forest and one in a temperate forest, such as those we find throughout Europe, will have largely the same response to drought and will inevitably suffer as a result of rising temperatures and changes in rainfall patterns on Earth.”

The biological and environmental scientists did find specific, varying features in different tree types can alter their resistance to drought. Species with denser wood and smaller, thicker leaves tend to fare better during prolonged, unusually-dry periods.

Read the full article: Science Daily

Trees overlooked as a source of income for farmers

 

Photo credit: Science Daily

Farms near forests tend to have more trees, which provide income and other benefits for local people, such as these farmers in the buffer zone of W National Park, Benin.
Credit: Daniel Miller

Trees supplement income for rural farmers in Africa

Date:
January 23, 2017
Source:
University of Illinois College of Agricultural, Consumer and Environmental Sciences
Summary:
Trees may be easy to spot on the plains of Africa but they are often overlooked as a source of income for farmers. A new study shows trees on farms may help reduce rural poverty and maintain biodiversity. The study used satellite images showing forest cover and nationally representative household-level data gathered from in-person interviews in Ethiopia, Malawi, Nigeria, Tanzania, and Uganda.

 

Read the full article: Science Daily

Deforestation and economy

 

 

Poor nations’ economies grow with rising deforestation

by Baraka Rateng’

Speed read

  • Researchers assessed the link between economic growth and deforestation
  • They found that in poor countries, increased deforestation leads to growth
  • An expert says the study is useful for formulating policies

Poor countries’ economic growth increases with deforestation rates but the effect disappears in wealthier economies, a study says.

According to researchers, climatic factors and inadequate data make it difficult to establish the link between economic development and overexploitation of natural resources.

But using satellite data, researchers were able to assess the link between deforestation rates and economic factors across countries.

“Our results quantify the potential costs that such policies could potentially have in terms of forest cover loss.”

Jesús Crespo Cuaresma, Vienna University of Economics and Business

The study published this month (16 January) in the journal Scientific Reports found that as developing countries become richer, a decrease in forest cover occurs, but such a relationship disappears at higher levels of income per capita.

“This implies that increases in deforestation, in particular in Sub-Saharan Africa, are expected as poorer economies converge in income per capita to that of developed countries,” says Jesús Crespo Cuaresma, a research scholar and professor of economics at the Vienna University of Economics and Business, who led the study.

Read the full article: SciDevNet

Patterns of tree death during extreme drought

 

Photo credit: Science Daily

How much drought can a forest take?

Aerial tree mortality surveys show patterns of tree death during extreme drought

Date:
January 19, 2017
Source:
University of California – Davis
Summary:
Why do some trees die in a drought and others don’t? And how can we predict where trees are most likely to die in future droughts? Scientists have examined those questions in a new study.

Scientists from the University of California, Davis, and colleagues examined those questions in a study published in the journal Ecology Letters.

Using climate data and aerial tree mortality surveys conducted by the U.S. Forest Service during four years (2012-2015) of extreme drought in California, they found that when a drought hits the region, trees growing in areas that are already dry are most susceptible.

The research also showed that the effects of drought on forests can take years to surface, suggesting that such effects may linger even after the drought has ended.

Southern Sierra Nevada trees are most vulnerable

The study said that trees in the driest and densest forests are the most at risk of dying in an extreme drought. In California, that makes crowded stands of trees in the Southern Sierra Nevada the most vulnerable in the state.

The concept is simple: Trees in dense forests are like multiple straws competing for the same glass of water. In wet climate conditions, that competition goes largely unnoticed. But when it’s dry, few are able to quench their thirst, setting the stage for mass mortality.

‘How much drought a tree can take’

Read the full story: Science Daily

Green manure cover crops and agroforestry

 

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COMACO Gliricidia/maize intercropping field. Photo credit: Christian Thierfelder/CIMMYT.

Addressing smallholder farmers’ needs with green manure cover crops and agroforestry in Zambia

 

Read the full story: Africa Rising

Forests store more carbon after logging due to favourable climate

 

 

Study maps carbon recovery after Amazon logging

by Rodrigo de Oliveira Andrade

Speed read

  • Selective logging improves carbon absorption by remaining trees
  • Research analysed 133 forest plots in 13 sites across Amazon rainforest
  • Forests from northern sites store more after logging due to favourable climate

Trees in the northern part of the Amazon rainforest recover their capacity to absorb carbon dioxide (CO2) from the atmosphere more quickly after selective logging compared with trees in the south where the climate is less favourable, a study reports.

Published in the journal eLife last month (December 20), the research assessed the dynamics of CO2 absorption in parts of the Amazon after they had been through selective logging — a practice where only the most valuable and biggest trees are cut down and collected.

“The low-impact, selective cutting of trees is vital to limiting damage to large, unharvested trees, which are critical for forest recovery.”

William Laurance, James Cook University

The Amazon rainforest accounts for up to 30 per cent of the total CO2stored by forests globally. But every year, selective logging contributes to the release of a big part of this stored carbon, contributing to global warming.

These emissions are cancelled out in the medium term, thanks to the carbon dynamics of the forests themselves: the remaining trees — those not harvested — and young trees — which regenerate naturally after logging— assimilate atmospheric carbon again.

Read the full article: SciDevNet

About the EU “action plan on deforestation”

 

Photo credit: CGIAR

A bird’s eye view of the stark contrast between the forest and agricultural landscapes near Rio Branco, Acre, Brazil. – Kate Evans/CIFOR

Can a deforestation driver become a forest protector?

Written by

The European Union likes to think of itself as environmentally minded and socially benevolent.  Green and sustainable.  That’s quite a long way from the truth.  For while the EU takes a global lead on climate change, it remains probably the world’s largest driver of tropical deforestation and the commercialization, centralization and globalization of agricultural systems across the developing world.

Could that be about to change? And can it help save smallholders as well as forests?

Every year millions of tonnes of soy, beef, palm oil, sugar, cocoa and other major agricultural commodities grown on former rainforest lands arrive at European ports.  An EU study in 2013 concluded that it was responsible for 36 per cent of deforestation arising from agricultural commodities.

Moreover, much of this commodity trade is in some manner illegal, the crops grown on land converted thanks to forged or bogus permits, breaches in land laws that involve grabbing land from smallholders and forest communities.

Read the full article: CGIAR