Forest holds high rodent diversity than other habitats under a rapidly changing and fragmenting landscape in Quirimbas National Park, Mozambique

Abstract

Habitat loss and fragmentation have widely recognised as the major challenge for biodiversity conservation across the world. This is particularly true in Quirimbas National Park (QNP) where holds unique fauna, and anthropogenic factors have been intensifying leading to a significant loss of biodiversity, especially rodents which play a vital role for the functioning of ecosystems. However, studies assessing rodent diversity, and deeply analysing spatiotemporal dynamics of this vulnerable landscape are still lacking although they are decisive for successful wildlife management and monitoring. This study aimed to assess the rodent diversity, change intensity and its driving forces, and fragmentation of different habitat types in QNP. Multi-temporal satellite images and field data were used to analyse the habitat fragmentation and change intensities at three levels (time interval, category, and transition) from 1990 to 2020. The stratified sampling and capture-recapture approaches were used to survey rodents in three habitats: forest, grassland and cropland. Ecological metrics were employed to measure rodent diversity, distribution and composition. Statistical tests were applied to check differences in rodent abundance and diversity among habitats. The findings revealed an increase in fragmentation of all habitats, and forest experienced the highest losses (107.3 km2) during 1990–2020. The annual rate change intensity was fast from 2010 to 2020. Cropland and built-up land experienced greater intensively gains and losses, while the annual change intensity of forest was dormant over time. Cropland and built-up land expanded at the expense of forest from 2010 to 2020, whereas from 2000 to 2010, cropland's gain targeted intensively grassland, built-up land and water body, and avoided forest. We recorded four rodent species: Acomys spinosissimus, Mastomys verreauxii, Dasymys incomtus and Aethomys chrysophilus; the last three species are new records for the park. Forest revealed the highest rodent diversity (Shannon entropy = 3.0), and the total species richness was comparable to previous studies in eastern Africa. We found significant differences in rodent abundance among habitats. Turnover and nestedness were the main cause of the overall beta diversity. This study can provide vital information for wildlife managers to better understand the process of habitat loss and fragmentation and its implication to biodiversity, which is crucial for applying appropriate conservation management.