Climate Action 2010-2011

Redd, Sustainable Forest Management and Agriculture
pesticides. In Costa Rica, plantation owners and farmers
have paid for the conservation of neighbouring forest for
the natural pest control they provide.
In addition, up to 35 per cent of the world’s agricultural
crops rely on pollinators for production, including forest
species of bats and honey bees. For example, coffee
cultivated in the fields furthest away from forested areas
has been shown to have lower yields due to reduced
pollination services. In addition, forests support the
conservation of soil and water needed for sustainable
agriculture, as trees can provide nutrients from leaf litter
and also reduce the erosion of nutrient-rich top soil.
Maintenance of natural forest cover can help control
erosion which reduces water quality and the lifespan of
irrigation infrastructure.
At broader scales, forests are often central to
maintaining water security. Forested catchments are a
vital source of freshwater for human use, supplying an
estimated 75 per cent of usable water globally. Recent
studies show that the conversion of forests to pastures in
Brazil may affect rainfall levels at the regional scale due to
reduced evapotranspiration with significant implications
for agricultural production.
The risks posed by deforestation and
degradation
Unfortunately, these flows of forest goods and services are
undermined or lost altogether when forests are converted
to other uses or degraded through unsustainable use.
According to the UN Food and Agriculture Organization
(FAO), the world’s area of tropical forests has continued
to shrink by 13 million hectares per year over the last
decade. The conversion of forested land to agricultural
crops, pasture, and plantations is the principle driver of
forest loss, aided by the intrusion of transport, mining
and other infrastructure.
Competition for land to produce food, fibre and
bioenergy has increased the pressure to convert natural
forests to other uses. Even when already-deforested land
is available for such purposes, governance failures drive
smallholders and commercial-scale investors alike to open
up relatively undisturbed forest land instead. Perverse
incentives may be created by conflicting ownership
claims on lands that have already been cleared, poor
law enforcement in remote areas and/or windfall profits
available from clearing standing timber on forested land
prior to replanting with another commercial crop.
Keeping forests as forests is the best way to maintain
their biodiversity. Even logged-over forests are much better
for conserving biodiversity than the land-uses that often
replace them, especially when they are adjacent to intact or
old-growth forests. And there are many practical steps that
can be taken to minimise the impact of timber extraction on
forest ecosystems. For example, the most important impacts
of logging on wildlife are often due to the increased hunting
pressure and habitat fragmentation caused by associated
road-building. Better regulation of hunting, reducing the
width of roads and maintaining biological corridors can go
a long way towards mitigating such impacts.
In addition, a switch to reduced impact logging
(RIL) could significantly decrease the impacts of timber
extraction on both wildlife and carbon emissions.
Inefficient and wasteful logging practices leave some 20
per cent of the volume of harvestable timber on the forest
floor to rot or fuel forest fires.
What we risk by depleting wildlife
One form of forest degradation – the depletion of wildlife
or ‘defaunation’ through hunting – is a particularly
insidious threat to the sustainability of forest goods and
services. When logging and mining are poorly regulated,
increased access to the forest can transform what was
formerly a sustainable subsistence activity into an
unsustainable commercial one. As a result, forests can be
depleted of their wildlife, with important implications for
both human livelihoods and ecological sustainability. Wild
meat is an important component of the diets of many
rural communities in terms of both nutritional needs and
cultural preference. The extirpation (local extinction) of
species can thus threaten human health and culture.
But survival of the forest itself also depends on
maintaining biodiversity. Individual species and
combinations of species play complex roles in sustaining
others. Forest fauna may also play key roles in the
pollination or seed dispersal necessary for the regeneration
of trees and other plants. For example, ungulates such
as wild pigs and antelopes are active seed dispersers and
predators, and their absence can have a significant impact
on forest regeneration and other ecosystem dynamics.
Wildlife grazing on plants or preying on other
species is often necessary to maintain species diversity,
maintain food chains and control pests. For example,
large herbivores such as elephants have a huge impact
on forest vegetation structure, influencing the relative
abundance of plant and other animal species. The loss of
such ‘keystone species’ can have a disproportionate impact
on the structure and composition of the ecosystem. Large
animals and top predators, such as large cats or crocodiles,
tend to be both keystone species and the preferred target
of hunters. Local extinction of such species caused by
uncontrolled hunting can thus result in significant loss of
forest function, even if the trees are left standing.
Forests are vulnerable to climate change
Forests have an important role to play in helping societies
adapt to climate change. Natural forests can help maintain
the quantity and quality of surface water flows for drinking
water and agricultural uses, even as rainfall patterns change.
They can also increase the resilience of rural communities
by providing a back-up source of food and income when
climate change induces crop failure or other loss of
livelihood. Diverse forest ecosystems are especially valuable
in the context of a changing climate because they provide
a variety of goods and services that reduce vulnerability to
disruption in any particular source of income.
It is also critical to recognise that forest ecosystems
themselves are threatened by climate change. Forests
are vulnerable to many of the predicted effects of global
warming. For example, increased average temperatures
and longer dry seasons are likely to combine to increase
the incidence and severity of forest fires such as those
experienced in Russia in mid-2010.
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