8/4/2019 PS_SahelianSavannaDisturbanceExp_20100211

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Project Summa

Sahelian Savanna Disturbance Experimen

Overview

avannas are ecosystems characterized by the simultaneous

esence of trees (or woody shrubs) and grasses in seasonally

y areas of the tropics and sub-tropics. This “coexistence”f very different types of plants is important in terms of the

nctioning of the ecosystem (e.g., vegetation growth, water 

e, carbon sequestration), but also in terms of how humans

net from and manage these unique systems (e.g., grazing

ttle or fuel-wood harvest). In Africa, the savannas are key

eas of biotic, economic and cultural diversity.

he Sahel-Sudan zone of West Africa is a savanna that is crucial

the rural economy of Africa north of the equator and for the

velihoods of the region’s pastoral and agricultural peoples. The

avannas are dened by the simultaneous presence of trees (or woody shrubs) and grasses in seasonally dry areas of the trop

nd sub-tropics. The region is subject to frequent drought, and resulting problems of food security, environmental degradation,

esertication. By understanding how human management practices impact ecological processes, scientists can help promote

ound management in the face of future changing climate.

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region is subject to frequent drought, with attendant proble

of food security, environmental degradation, and perceived

 problems of desertication. Understanding of how humanmanagement practices, especially grazing and re, impact

ecological processes will help scientists develop best pract

for sound land management and help the region’s people ad

to climate change looming on the horizon.

Collaborators from Colorado State University and universi

in Mali have designed a comprehensive eld experiment to

examine the interactive effects of re and large herbivores

savanna vegetation across the West African rainfall gradien

from dry Sahel in the north to wetter savannas in the south

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ving problems at the interface of livestock production and science-based environmental management.

www.livestockandenvironment.info

herd of cattle moves through the savanna in Mali. Understanding the role of re, grazing, and vegetation will help cattle herde

nd rural communities adapt to climate change (Photo: Niall Hanan).

More Information

Niall Hanan Phone/Email

Research Scientist 970-491-4112Natural Resource Ecology niall.hanan@colostate.eduLaboratory (NREL)Colorado State University

LinksInstitute for Livestock & the Environment:www.livestockandenvironment.info

NREL Program for African Ecosystems:www.nrel.colostate.edu/african-program.html

Objectives

1. Examine how grazing by domestic animals, and ground-

affect vegetation dynamics in West African savannas.

2. Explore cascading impacts of re and herbivory on micr

invertebrate, and vertebrate species and impacts on ecosyst

functions such as carbon, water and nutrient cycles.

3. Assess the role of alternative land use options available t

rural populations in West Africa for their contrasting econoand ecological impacts and long-term social-ecological

sustainability.

t each site fences and re-breaks exclude domestic livestock,

res, and combined res and livestock, from experimental

ots. The team will monitor vegetation growth to examine how

sturbances impact survival and growth of trees and grasses,

etermine the role of disturbance in changing vegetation

ructure, and how these patterns change across the rainfall

adient.

he experiment will provide much needed empirical data

n tree-grass interactions in West African savannas and

omplement research elsewhere in Africa, Australia and Southmerica. This work contributes to ecological theory for 

vannas and the role of disturbance in species coexistence.

addition, this project will build long-term collaborative and

ientic links between two research and teaching institutions

Mali (University of Bamako and the Institute Polytechnique

ural) and researchers and students at Colorado State

niversity.

his project will provide unique research experiences, and

ternational scientic/cultural exposure, to U.S. students, and

cilitate development of a collaborating nucleus of Africannd U.S. researchers that will endure well into the future.

he project provides U.S. researchers and students signicant

pportunities to work in Africa, and African researchers and

udents opportunities to develop long-term research interests in

ollaboration with U.S. counterparts.