Spatial Evolution of Prosopis Invasion and its Effects on LULC and Livelihoods in Baringo, Kenya

Remote Sensing

Urs Schaffner¹  Sandra Eckert²  Wai-Tim Ng³  Maina Gichaba⁴  PurityRima Mbaabu⁴  Silas Oriaso⁴  Daniel Olago⁴  Simon Choge⁵ 

[1] Centre for Agriculture and Biosciences International (CABI), 2800 Delémont, Switzerland;Centre for Development and Environment, University of Bern, 3012 Bern, Switzerland;Earth Observation Data Centre for Water Resources Monitoring GmbH (EODC), Franz-Grill-Straße 9, 1030 Vienna, Austria;Institute for Climate Change and Adaptation (ICCA), University of Nairobi, P.O. Box 30197, Nairobi, Kenya;Kenya Forestry Research Institute (KEFRI), P.O. Box 57-30403, Marigat, Kenya;

关键词: biological invasion;    prosopis;    landsat;    random forest;    land use land cover change;    Kenya;   

DOI  :  10.3390/rs11101217

来源: DOAJ

【 摘 要 】

Woody alien plant species have been deliberately introduced globally in many arid and semi-arid regions, as they can provide services and goods to the rural poor. However, some of these alien trees and shrubs have become invasive over time, with important impacts on biodiversity, ecosystem services, and human well-being. Prosopis was introduced in Baringo County, Kenya, in the 1980s, but since then, it has spread rapidly from the original plantations to new areas. To assess land-use and land-cover (LULC) changes and dynamics in Baringo, we used a combination of dry and wet season Landsat satellite data acquired over a seven-year time interval between 1988−2016, and performed a supervised Random Forest classification. For each time interval, we calculated the extent of Prosopis invasion, rates of spread, gains and losses of specific LULC classes, and the relative importance of Prosopis invasion on LULC changes. The overall accuracy and kappa coefficients of the LULC classifications ranged between 98.1−98.5% and 0.93−0.96, respectively. We found that Prosopis coverage increased from 882 ha in 1988 to 18,792 ha in 2016. The highest negative changes in LULC classes were found for grasslands (−6252 ha; −86%), irrigated cropland (−849 ha; −57%), Vachellia tortilis-dominated vegetation (−3602 ha; −42%), and rainfed cropland (−1432 ha; −37%). Prosopis invasion alone directly accounted for over 30% of these negative changes, suggesting that Prosopis invasion is a key driver of the observed LULC changes in Baringo County. Although the management of Prosopis by utilization has been promoted in Baringo for 10−15 years, the spread of Prosopis has not stopped or slowed down. This suggests that Prosopis management in Baringo and other invaded areas in East Africa needs to be based on a more integrated approach.

【 授权许可】

Unknown