Biodiversity and tropical forest plantations
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Transcript of Biodiversity and tropical forest plantations
Biodiversity and tropical forest plantations
German-CIFOR Workshop on “Rethinking Tropical Plantations”
Bulungan room, CIFOR, Bogor, 7-10 December 2004
What are we talking about?
Plantations are evil!
Plantations are often linked to serious risks:
Social (cheap labour, exploitation, displace local people…)Environmental (destroy forests, exotics, exhaust water…) Financial (debt, perverse incentives…)
There is no room for biodiversity in these [Pine] plantations. They are “green deserts” that have lost ecosystem multi-functionality, and the neighbours have perceived this situation, baptising them “the forests of silence” (WRM 2003)
What are really forest plantations?
Defining plantation is surprisingly complex
From monoclonal Eucalypt stands to complex Damar agroforests
From trees on farm for fuelwood to large estates for pulp and paper
For this work:
Forest stands established by planting and/or seeding in the process of afforestation or reforestation. They are either of introduced species (all planted stands) or intensively managed stands of indigenous species, which meet all the following criteria: one or two species at planting; even age class; regular spacing
Are there environmental risks linked to forest plantations?
Done at the expense of ‘primary’ ecosystems (forests or grasslands)Monocultures based on a narrow genetic baseExotic species that could become invasiveConsume large quantities of waterExhaust soils resources and increase erosion…
Are forest plantations taking pressure off natural forests?
Maybe…New Zealand being the archetypal example
Ghana, Uganda, Uruguay, Chile, Fiji
Maybe not…Not a replacement for most high value timber
Main cause of deforestation is agriculture (incl. cash crop plantations)
‘Logging off’ is more the result of awareness of acute natural forest shortage than of compensatory effects from plantations
Do we need tropical forest plantations?
Yes, for various reasonsEvidence is against the idea of ‘demand reduction’. Demand increases (as is recycling but not enough to offset the demand)By 2050 the World will need an additional 66-101 million ha of forest plantations (54-81 millions for wood energyPlantations are best suited to provide large quantity of uniform material (industrial wood, pulp wood) that is in increasing demandThe area of tropical natural forests that can be economically or legally logged is going to decline drastically
The potential for tropical forest plantations to contribute to biodiversity conservation
The big principles
Maintain connectivity of the landscape for animals
Maintain biological diversity both flora and fauna
Protect fragile or ecologically important habitats
Reduce necessary damaging principles to a minimum
Landscape level management
ConnectivityLeave native vegetation as biological legacies throughout cutting cycles (dispersed individual retention trees, aggregated clumps, linear strips)
Maintain corridors or buffer strips along rivers and streams
Maintain blocks of native forests linked to the existing corridor network or ensure that corridors are linked to existing native forest reserves outside planting areas
Where exotics are used widely, begin or increase planting of native species, increase emphasis on retaining areas of native vegetation
Spatially and temporally juxtapose exotic and native stands within a landscape
Stand level management (1)
HarvestWhen harvesting mature plantations, leave as many snags and cavity trees as possible.Delimb trees near the stump, and leave tops on site.Manage some plantations on longer rotations. Instead of clear-cutting all mature plantations, manage some via irregular shelterwood, seed–tree cuts, or selection silviculture.
Species compositionFavor native species over exotics.Retain underplant important plant species that provide mast, fruit, nectar, or cavity resources. Maintain genetic diversity. Avoid widespread use of seed from a limited number of individuals, or clones.Favor mixed species plantations either within or between stands
Stand level management (2)
Site preparationAvoid intensive site-preparation that disturbs soil nutrients, promotes leaching and soil erosion Leave some snags and downed coarse woody debris after site preparationUse controlled burning over part of the landscape to promote native understorey plants
TendingThin some plantations earlier and heavier than normal, to stimulate or maintain a diverse understorey plant community. Leave sections unthinned to create a mosaic of relatively open areas and dense thickets. Allow incomplete herbicide applications that skip some areas, or thin competing vegetation to acceptable levels instead of trying to clean stands completely.
In lieu of conclusion
Are forest plantations evil?
Not by nature, even for fast growing plantations (pulp, industrial wood)It depends essentially on the management practices applied both within stands and at the landscape levelGood management practices are neither complicated nor necessarily expensive to implementThere is however a “company cost / overall society benefit” to biodiversity friendly practices: good players should be rewarded; bad ones should be punished
Useful references
Cossalter, C. & C. Pye-Smith 2003. Fast-Wood forestry: Myths and reality. Forest Perspectives, CIFOR, Bogor, Indonesia
Hardcastle, P.D. 1999. Plantations: potential and limitations. Draft report for the World Bank Forest Policy Implementation review and Strategy.
Hartley, M.J. 2003. Rationale and methods for conserving biodiversity in plantation forests. Forest Ecology and Management 155:81–95
Poulsen, J., G. Applegate & D. Raymond 2001. Linking C&I to a code of practice for industrial forest plantations. CIFOR, Bogor, Indonesia
World Rainforest Movement 2003. Plantations are not forests. On-line http://www.wrm.org.uy/publications