Modelling the impact of climate change on Tanzanian forests

• Published in: Diversity & distributions Vol. 26; no. 12; pp. 1663 - 1686
• Main Authors: John, Elikana, Bunting, Pete, Hardy, Andy, Roberts, Osian, Giliba, Richard, Silayo, Dos Santos
• Format: Journal Article
• Language: English
• Published: Oxford Wiley 01.12.2020; John Wiley & Sons, Inc
• Subjects: Biodiversity; Biodiversity conservation; Biodiversity hot spots; BIODIVERSITY RESEARCH; Biofuels; Climate change; Climate models; Climate prediction; Conservation; conservation areas; conservation planning; Emission; Emissions; Entropy; Environmental impact; fauna; Flora; Forest communities; forest damage; Forest degradation; Forest ecosystems; forest habitats; forest inventory; Forests; habitat destruction; Habitat fragmentation; Habitat loss; habitat suitability modelling; Habitats; land; Land degradation; Land reclamation; land restoration; Land use; Land use management; Land use planning; lowland forests; Mangroves; MaxEnt modelling; Maximum entropy; Microenvironments; Microhabitats; Montane environments; montane forests; Mountain forests; Mountains; National forests; pressing; probability; Protected areas; Tanzania; Terrestrial ecosystems; Woodlands; Indian Ocean; Africa; Tanzania
• DOI: 10.1111/ddi.13152
• ISSN: 1366-9516

Aim Climate change is pressing extra strain on the already degraded forest ecosystem in Tanzania. However, it is mostly unknown how climate change will affect the distribution of forests in the future. We aimed to model the impacts of climate change on natural forests to help inform national‐level conservation and mitigation strategies. Location Tanzania. Methods We conducted maximum entropy (MaxEnt) modelling to simulate forest habitat suitability using the Tanzanian national forest inventory survey (1,307 occurrences) and environmental data. Changes in forest habitats were simulated under two Representative Concentration Pathways (RCPs) emission scenarios RCP 4.5 and RCP 8.5 for 2055 and 2085. Results The results indicate that climate change will threaten forest communities, especially fragmented strips of montane forests. Even under optimistic emission scenario, the extent of montane forest is projected to almost halve by 2085, intersecting many biodiversity hotspots across the Eastern Arc Mountains. Similarly, climate change is predicted to threaten microhabitat forests (i.e. thickets), with losses exceeding 70% by 2085 (RCP8.5). Other forest habitats are predicted to decrease (lowland forest and woodland) representing essential ecological networks, whereas suitable habitats for carbon‐rich mangroves are predicted to expand by more than 40% at both scenarios. Conclusions Climate change will impact forests by accelerating habitat loss, and fragmentation and the remaining land suitable for forests will also be subject to pressures associated with rising demand for food and biofuels. These changes are likely to increase the probability of adverse impacts to the country's indigenous flora and fauna. Our findings, therefore, call for a shift in conservation efforts, focusing on (i) the enhanced management of existing protected areas that can absorb the impacts of future climate change, and (ii) expanding conservation efforts into newly suitable regions through effective land use planning and land reclamation, helping to preserve and enhance forest connectivity between fragmented patches.