Two of the most rapidly increasing threats to our planet’s biodiversity are land use change and climate change. The rapid shift to large-scale agricultural practices, urbanization, deforestation, and other land use practices are destroying wildlife habitat and fragmenting remaining populations. Climate change is having profound and growing impacts on temperature, rainfall, vegetation, soils, and water flow.
These rapid changes also bring a corresponding increase in the risk of disease. WCS is in the forefront of studies related to land use and climate change and the complex but growing evidence that these impacts are increasing the likelihood that disease will grow as a threat to wildlife and to humans. Land use change is leading to clear increases in pathogen movement and transmission. Shifts in temperature enable infectious agents to move northward and upward into mountains, while shifts in temperature and precipitation can cause previously benign agents to become pathogenic. An example of the latter is the bacterium Pasteurella multocida, which normally lives in saiga antelope tonsils but became pathogenic in 2015 after unusual weather events, and killed off over half the global saiga population in just a few weeks.
Ecological degradation and land-use change are considered major drivers of zoonotic pathogen emergence. Empirical evidence is still too scarce to allow a mechanistic understanding of causal relationships between land-use change and disease emergence and WCS is working to elevate the science. WCS is leading activities on the ground in Bolivia and Colombia for the transdisciplinary SIMPEL project, led by the Leibniz Institute for Zoo and Wildlife Research (IZW) and funded by the Volkswagen Foundation, to acquire a deeper understanding of the socio-economic, cultural, and ecological impacts of land-use change, and the consequences on the health and livelihoods of vulnerable populations living in these altered landscapes. Spillovers of deadly zoonotic pathogens have already occurred in these changing Latin American landscapes, including hemorrhagic fevers and the first cases of Hantavirus in the La Paz department of Bolivia, in sugar mill workers during the conversion of lowland forest to sugar cane. Human-vector contact in newly created forest edges has increased risks of malaria in Peru, leishmaniasis in Costa Rica, and hantavirus in Panama.
The LACANET project, of which WCS was a key partner, looked at the impacts of deforestation on emerging diseases in Cambodia, where forest cover has decreased dramatically in the past decade.
Photo Credit: Julie Larsen Maher, WCS