Modeling impacts of climate change on the geographic distribution and abundances of Tamarindus indica in Tigray region, Ethiopia

Yirga Gufi; Ashenafi Manaye; Berihu Tesfamariam; Haftu Abrha; Musse Tesfaye; Sibhatleab Hintsa

doi:10.1016/j.heliyon.2023.e17471

Modeling impacts of climate change on the geographic distribution and abundances of Tamarindus indica in Tigray region, Ethiopia

Heliyon. 2023 Jun 27;9(7):e17471. doi: 10.1016/j.heliyon.2023.e17471. eCollection 2023 Jul.

Authors

Yirga Gufi¹, Ashenafi Manaye², Berihu Tesfamariam¹, Haftu Abrha^{3

4

5}, Musse Tesfaye⁶, Sibhatleab Hintsa⁷

Affiliations

¹ Ethiopian Forest Development, Mekelle Centre, Mekelle, Ethiopia.
² Tigray Institute of Policy Studies, Mekelle, Ethiopia.
³ Institutes of Climate and Society, Mekelle University, Mekelle, Ethiopia.
⁴ University Felix Houphouet-Boigny, Abidjan, Cote d'Ivoire.
⁵ Mohammed VI Polytechnic University, Lot 660, Hay Moulay Rachid, Ben Guerir, 43150, Morocco.
⁶ Institute of International Forestry and Forest Products, Technical University of Dresden, 01737, Tharandt, Germany.
⁷ Tigray Agricultural Research Institute, Abergelle Agricultural Research Center, Ethiopia.

Abstract

Tamarindus indica is a multipurpose dry land species in sub-Saharan that is traditionally used to build resilience into the farming system. The species is highly threatened and listed on the IUCN Red List. However, information on how climatic condition locally influences its ecological distribution is limited. This study investigates the current and future suitable habitat for the species in the Tigray region, in northern Ethiopia. A total of 220 species presence points and the number of T. indica within a 50 m × 50 m plot were collected. In addition, 19 bioclimatic variables, 3 topographic variables and soil data were used to model the impact of future climate conditions under two Representative Concentration Path Ways (RCP4.5 and RCP 8.5). MaxEnt-v-3.3.3 k, Diva-GIS-7.5, and GIS10.6 were used to model the current and future distribution. SPSSv-26 was also utilized to analyze the relationship between the species' abundance and environmental variables. Results showed that the environmental variables determining most for the distribution of T. indica were mean diurnal range (Bio2 (56.9%)); temperature seasonality (Bio4 (10.3%)) and temperature annual range (Bio7 (9.2%)). The model suggested that the current distribution of T. indica covers an area of 9209 km² (14.04%). This would have increased to 29,363 km² (44.78%) and 11,046 km² (16.85%) by 2070 under RCP4.5 and RCP8.5, respectively. Compared to the high-impact areas, new gains of suitable areas (net 25,081 km²) for the future distribution of the species were predicted in 2070-RCP4.5. Altitude, rainfall, temperature, silt contents of soils and soil pH have significant contributions (P-value<0.05) to the abundance of T. indica. However, altitude has a negative relationship with the abundance of T. indica. Additional studies to understand population trends and other threats are recommended.

Keywords: Abundance; Climate change; Future distribution; Maximum entropy (MaxEnt); Tamarindus indica.