Mapping current and potential distribution of non-native Prosopis juliflora in the Afar region of Ethiopia

Tewodros T Wakie; Paul H Evangelista; Catherine S Jarnevich; Melinda Laituri

doi:10.1371/journal.pone.0112854

Mapping current and potential distribution of non-native Prosopis juliflora in the Afar region of Ethiopia

PLoS One. 2014 Nov 13;9(11):e112854. doi: 10.1371/journal.pone.0112854. eCollection 2014.

Authors

Tewodros T Wakie¹, Paul H Evangelista², Catherine S Jarnevich³, Melinda Laituri⁴

Affiliations

¹ Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, United States of America; Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado, United States of America.
² Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado, United States of America.
³ US Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States of America.
⁴ Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, Colorado, United States of America.

Abstract

We used correlative models with species occurrence points, Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices, and topo-climatic predictors to map the current distribution and potential habitat of invasive Prosopis juliflora in Afar, Ethiopia. Time-series of MODIS Enhanced Vegetation Indices (EVI) and Normalized Difference Vegetation Indices (NDVI) with 250 m2 spatial resolution were selected as remote sensing predictors for mapping distributions, while WorldClim bioclimatic products and generated topographic variables from the Shuttle Radar Topography Mission product (SRTM) were used to predict potential infestations. We ran Maxent models using non-correlated variables and the 143 species- occurrence points. Maxent generated probability surfaces were converted into binary maps using the 10-percentile logistic threshold values. Performances of models were evaluated using area under the receiver-operating characteristic (ROC) curve (AUC). Our results indicate that the extent of P. juliflora invasion is approximately 3,605 km2 in the Afar region (AUC = 0.94), while the potential habitat for future infestations is 5,024 km2 (AUC = 0.95). Our analyses demonstrate that time-series of MODIS vegetation indices and species occurrence points can be used with Maxent modeling software to map the current distribution of P. juliflora, while topo-climatic variables are good predictors of potential habitat in Ethiopia. Our results can quantify current and future infestations, and inform management and policy decisions for containing P. juliflora. Our methods can also be replicated for managing invasive species in other East African countries.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Ethiopia
Introduced Species*
Prosopis / physiology*

Grants and funding

Tewodros Wakie acknowledges support from the National Needs Fellowship program of the National Institute of Food and Agriculture, U.S. Department of Agriculture (Award Number- 2010-03280). Additional funding was provided by the U.S. Forest Service International Program (http://www.fs.fed.us/global/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.