A 40-year evaluation of drivers of African rainforest change

Forest Ecosystems

卷:8

Urs Kalbitzer¹  Colin A. Chapman²  Dipto Sarkar³  Carmen Galán-Acedo⁴  Patrick A. Omeja⁵  Anna Sugiyama⁶  Michael J. Lawes⁷  Rong Hou⁸  Jan F. Gogarten⁹ 

[1] Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior;

[2] Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University;

[3] Department of Geography and Environmental Studies, Carleton University;

[4] Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México;

[5] Makerere University Biological Field Station;

[6] School of Life Sciences, Harold L. Lyon Arboretum, University of Hawai‘i at Mānoa;

[7] School of Life Sciences, University of KwaZulu-Natal;

[8] Shaanxi Key Laboratory for Animal Conservation, Northwest University;

[9] Viral Evolution and Epidemiology of Highly Pathogenic Microorganisms, Robert Koch Institute;

关键词: Climate change;    Elephants;    Succession;    Primates;    Disturbance;    Forest regeneration;   

DOI  :  10.1186/s40663-021-00343-7

来源: DOAJ

【 摘 要 】

Abstract Background Tropical forests are repositories of much of the world’s biodiversity and are critical for mitigation of climate change. Yet, the drivers of forest dynamics are poorly understood. This is in large part due to the lack of long-term data on forest change and changes in drivers. Methodology We quantify changes in tree abundance, diversity, and stand structure along transects first enumerated in 1978 and resampled 2019 in Kibale National Park, Uganda. We tested five predictions. First, based on the purported role of seed dispersal and herbivory and our quantification of changes in the abundance of frugivores and herbivores, we tested two predictions of how faunal change could have influenced forest composition. Second, based on an evaluation of life history strategies, we tested two predictions concerning how the forest could have changed following disturbance that happened prior to written history. Finally, based on a 50-year climate record, we evaluate the possible influence of climate change on forest dynamics. Results More trees were present on the assessed transects in 2019 (508) than in 1978 (436), species richness remained similar, but diversity declined as the number of dominant species increased. Rainfall increased by only 3 mm over the 50 years but this had not significant effect on forest changes measured here. Annual average monthly maximum temperature increased significantly by 1.05 °C over 50 years. The abundance of frugivorous and folivorous primates and elephants increased over the 50 years of monitoring. Neither the prediction that an increase in abundance of seed dispersing frugivores increases the abundance of their preferred fruiting tree species, nor that as an increase in folivore abundance causes a decline in their preferred species were supported. As predicted, light-demanding species decreased in abundance while shade-tolerant species increased as expected from Kibale being disturbed prior to historical records. Finally, while temperature increased over the 50 years, we found no means to predict a priori how individual species would respond. Conclusions Our study revealed subtle changes in the tree community over 40 years, sizable increases in primate numbers, a substantial increase in the elephant population and an increase in local temperature. Yet, a clear picture of what set of interactions impact the change in the tree community remains elusive. Our data on tree life-history strategies and frugivore/herbivore foraging preferences suggest that trees species are under opposing pressures.

【 授权许可】

Unknown