Download Land use change trends and Impact on Mountain

Land use change trends and Impact on
Mountain Biodiversity:
a global perspective
Eva Spehn
Global Mountain Biodiversity Assessment
of DIVERSITAS
Land use change & Mountain biodiversity
Most wide spread utilization of mountain terrain:
• Upland grazing,
• often facilitated by fire management
• often followed by erosion and enhanced risk for valley and foreland
environments.
Most land use changes reduce mountain biodiversity, especially:
• Cultivation of formerly pristine areas
• Intensification of agriculture/husbandry in montane areas
• Abandonment of formerly grazed montane & alpine grasslands
Biodiversity in the
European Alps
Intensification
Two opposite trends:
Abandonment
Stöcklin J, Bosshard A, Klaus G, RudmannRudmann-Maurer K, Fischer M (2006)
Land cover change
-> consequences for
biodiversity
© Silvia Vananderoye
Stöcklin J, Bosshard A, Klaus G, RudmannRudmann-Maurer K, Fischer M (2006)
Land use change and mountain biodiversity
Focus: (sub)tropical mountains
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2 Workshops: Moshi,Tanzania 2002 & La Paz, Bolivia 2003
Research Agenda (2005)
Synthesis book (2006)
Network of
field experiments 20052005-
Financed by
• Swiss Agency for Dev. and Cooperation SDC,
• Food and Agricultural Organisation FAO
• Swiss National Science Fondation
GMBA Moshi-La Paz Research Agenda (2005)
Providing priority research questions on land use effects on
mountain biodiversity, specifically on :
• The use of highland vegetation and husbandry systems (food)
• Fire ecology
• Highland cropping, hunting and gathering, and medicinal plants
• Regeneration and re-vegetation outside forests
• Upper montane forest and high elevation treelines (fiber and fuel)
• Cross cutting research issues: Hydrology and erosion, interactions
of land use with climate change, indigenous knowledge
Land use change & Mountain biodiversity
Synthesis book:
Studies of fire and grazing effects on mountain
biodiversity in:
Andes (Argentina, Bolivia, Colombia, Peru,
Venezuela)
African Mountains (Tanzania, Uganda,
Madagascar, South-Africa)
Alps, Caucasus, Pamir, Himalaya, Snowy
Mountains
How does fire intensity or fire frequency in mountains
affect biodiversity?
Increase of Fire frequency at Kilimadjaro:
from
Podocarpus forest
to Erica bushes:
the loss of a life form (trees)
(Hemp 2006, in Spehn, Liberman & Körner: Land use change and mountain biodiversity)
Fire effects on mountain biodiversity:
• Burnt areas are commonly poorer in species than unburnt
areas (especially in uniform plots and if unburnt control
contains forest)
• Fire leads to degradation (e.g. of Paramo tussocks) if the
regeneration takes longer than the burning frequency.
• Woody components become eliminated or very uniform (Erica
(Erica
shrub in African mountains)
• Moderate fires do not necessarily reduce plant cover and
diversity, but induce a change in ecosystem functioning (e.g.
Kilimanjaro: lost of cloud water trapping by destruction of Erica
forest)
How do changes in grazing regime in mountains
affect biodiversity?
• How does grazing and the pace of land use changes in
mountains enhance or reduce biodiversity?
Grazing effects on mountain biodiversity
• Moderate grazing increases plant species diversity at local
scale, as herbivory increases the competitive ability of other
taxa ((Intermediate
Intermediate disturbance hypothesis)
hypothesis)
• Grazing of high elevation grassland with a long history of
ungulate presence commonly has little impact on biodiversity
as long as stocking rates do not cause highly palatable species
to disappear
(Sarmiento et al; Bustamante et al; Rawat & Adhikari 2006,
in Spehn, Liberman & Körner: Land use change and mountain biodiversity)
Sustainable grazing management in subtropical highlands
Appropriate stocking rates:
• Best indicator is the abundance of lessless-palatable dominants vs.
highlyhighly-palatable subdominants (robust vs. nutritious species)
• Key role of marshmarsh-type meadows (dry parts of Inner
Inner--Himalaya;
bofedales in the Andes) during dry periods: their capacity
determines the total stocking rate of a region.
Appropriate animal selection:
• “Picky animals” (cattle, sheep, alpaca) have much stronger
impact on diversity and pasture quality than species with a
broad food selection (e.g. llama).
(Bustamante et al; Alzerreca et al., Molinillo & Monasterio 2006,
in Spehn, Liberman & Körner: Land use change and mountain biodiversity)
Interaction effects of fire and grazing on biodiversity
Joint Research Projects established on
Land use, mountain biodiversity and
ecosystem services:
services:
European Alps (Switzerland, Austria, and France)
Caucasus (Georgia)
Andes (Altiplano/Bolivia)
Himalayas (Tibet/China)
www.gmba.unibas.ch