Serengeti–Masai Mara ecosystem dynamics inferred from rainfall extremes

The Serengeti–Masai Mara Ecosystem (SMME) is an iconic ecological and biodiversity resource in East Africa with a spectacular great animal migration feature. Environmental shocks like droughts, floods, and land degradation threaten the SMME’s ecological functioning. However, the spatiotemporal ecosy...

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Main Authors: Zacharia Florence Mtewele, Gensuo Jia, Xiyan Xu
Format: Article
Language:English
Published: IOP Publishing 2023-01-01
Series:Environmental Research Letters
Subjects:
Online Access:https://doi.org/10.1088/1748-9326/ad01cb
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author Zacharia Florence Mtewele
Gensuo Jia
Xiyan Xu
author_facet Zacharia Florence Mtewele
Gensuo Jia
Xiyan Xu
author_sort Zacharia Florence Mtewele
collection DOAJ
description The Serengeti–Masai Mara Ecosystem (SMME) is an iconic ecological and biodiversity resource in East Africa with a spectacular great animal migration feature. Environmental shocks like droughts, floods, and land degradation threaten the SMME’s ecological functioning. However, the spatiotemporal ecosystem dynamics during climate extremes are inadequately examined. Here we quantified water availability and vegetation changes during extreme wet (EWE) and dry (EDE) events over the SMME for wet and dry seasons in 1982–2020. We derived extreme events from seasonal mean precipitation anomaly exceeding standard deviation and applied composite and correlation techniques to assess their dynamics with animal populations and migration prospects. Wet season EWE increases vegetative and moist conditions over southern SMME, suggesting elongating migrants’ occupancy compared to normal periods and delayed northward migration. Wet season EDE significantly suppresses these features, heightening ecosystem competition and survival threats, proposing an earlier northward migration. Dry season EWE increases vegetation and water availability over northern SMME, prompting the late southward migration. Dry season EDE significantly reduces vegetation and water availability over northern SMME, suggesting an early southward migration towards regions with more vegetation and increased water availability. The SMME also experiences multiple EDE occurring in consecutive seasons, prolonging dry conditions that aggregate wildlife survival threats. Notably, two EDE prevailed consecutively from the 1993 dry season to the 1994 wet season, coupled with a population decline of wildebeest (1.2–0.9 million), buffalo (40–20 thousand), and lion (1.3–0.9 thousand). We also note a reversal from more EDE to EWE during the study period. Prevalent EWE can lessen wet and vegetative conditions distribution gradient, which is imperative for the functioning of the SMME migratory ecosystem. Our study unveiled hotspot areas of extremes-driven ecosystem changes for the sustainable SMME migratory functioning essential for framing meaningful conservation management policies under climate change.
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spelling doaj.art-982b806702b94df2bc176c7675b302412023-10-17T08:14:23ZengIOP PublishingEnvironmental Research Letters1748-93262023-01-01181111402610.1088/1748-9326/ad01cbSerengeti–Masai Mara ecosystem dynamics inferred from rainfall extremesZacharia Florence Mtewele0https://orcid.org/0000-0003-3559-3486Gensuo Jia1https://orcid.org/0000-0001-5950-9555Xiyan Xu2https://orcid.org/0000-0003-2732-1325Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, People’s Republic of China; University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of China; Physics Department, College of Natural and Applied Sciences, University of Dar es Salaam , Dar es Salaam 35063, TanzaniaKey Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, People’s Republic of China; University of Chinese Academy of Sciences , Beijing 100049, People’s Republic of ChinaKey Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing 100029, People’s Republic of ChinaThe Serengeti–Masai Mara Ecosystem (SMME) is an iconic ecological and biodiversity resource in East Africa with a spectacular great animal migration feature. Environmental shocks like droughts, floods, and land degradation threaten the SMME’s ecological functioning. However, the spatiotemporal ecosystem dynamics during climate extremes are inadequately examined. Here we quantified water availability and vegetation changes during extreme wet (EWE) and dry (EDE) events over the SMME for wet and dry seasons in 1982–2020. We derived extreme events from seasonal mean precipitation anomaly exceeding standard deviation and applied composite and correlation techniques to assess their dynamics with animal populations and migration prospects. Wet season EWE increases vegetative and moist conditions over southern SMME, suggesting elongating migrants’ occupancy compared to normal periods and delayed northward migration. Wet season EDE significantly suppresses these features, heightening ecosystem competition and survival threats, proposing an earlier northward migration. Dry season EWE increases vegetation and water availability over northern SMME, prompting the late southward migration. Dry season EDE significantly reduces vegetation and water availability over northern SMME, suggesting an early southward migration towards regions with more vegetation and increased water availability. The SMME also experiences multiple EDE occurring in consecutive seasons, prolonging dry conditions that aggregate wildlife survival threats. Notably, two EDE prevailed consecutively from the 1993 dry season to the 1994 wet season, coupled with a population decline of wildebeest (1.2–0.9 million), buffalo (40–20 thousand), and lion (1.3–0.9 thousand). We also note a reversal from more EDE to EWE during the study period. Prevalent EWE can lessen wet and vegetative conditions distribution gradient, which is imperative for the functioning of the SMME migratory ecosystem. Our study unveiled hotspot areas of extremes-driven ecosystem changes for the sustainable SMME migratory functioning essential for framing meaningful conservation management policies under climate change.https://doi.org/10.1088/1748-9326/ad01cbclimate extremesecosystem dynamicsgreat animal migrationSerengeti–Masai Mara ecosystemEast Africa
spellingShingle Zacharia Florence Mtewele
Gensuo Jia
Xiyan Xu
Serengeti–Masai Mara ecosystem dynamics inferred from rainfall extremes
Environmental Research Letters
climate extremes
ecosystem dynamics
great animal migration
Serengeti–Masai Mara ecosystem
East Africa
title Serengeti–Masai Mara ecosystem dynamics inferred from rainfall extremes
title_full Serengeti–Masai Mara ecosystem dynamics inferred from rainfall extremes
title_fullStr Serengeti–Masai Mara ecosystem dynamics inferred from rainfall extremes
title_full_unstemmed Serengeti–Masai Mara ecosystem dynamics inferred from rainfall extremes
title_short Serengeti–Masai Mara ecosystem dynamics inferred from rainfall extremes
title_sort serengeti masai mara ecosystem dynamics inferred from rainfall extremes
topic climate extremes
ecosystem dynamics
great animal migration
Serengeti–Masai Mara ecosystem
East Africa
url https://doi.org/10.1088/1748-9326/ad01cb
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AT xiyanxu serengetimasaimaraecosystemdynamicsinferredfromrainfallextremes