Pamela R. Narváez-Torres, Nicola K. Guthrie, Typhenn A. Brichieri-Colombi, Cressant P. Razafindravelo, Zachary S. Jacobson, Fredo Tera, Daniel V. Rafidimanana, Zé-Elinah Rahasivelo, Melody A. Petersen, Hasinala Ramangason, Lea Randall, Jana M. McPherson, Cynthia L. Frasier, Axel Moehrenschlager, Sheila M. Holmes, Edward E. Louis Jr., Steig E. Johnson
{"title":"失去狐猴:种群减少与土地覆盖随时间和空间的变化。","authors":"Pamela R. Narváez-Torres, Nicola K. Guthrie, Typhenn A. Brichieri-Colombi, Cressant P. Razafindravelo, Zachary S. Jacobson, Fredo Tera, Daniel V. Rafidimanana, Zé-Elinah Rahasivelo, Melody A. Petersen, Hasinala Ramangason, Lea Randall, Jana M. McPherson, Cynthia L. Frasier, Axel Moehrenschlager, Sheila M. Holmes, Edward E. Louis Jr., Steig E. Johnson","doi":"10.1002/ajp.23615","DOIUrl":null,"url":null,"abstract":"<p>Forest loss and degradation due to land cover changes imperil biodiversity worldwide. Subtropical and tropical ecosystems experience high deforestation rates, negatively affecting species like primates. Madagascar's endemic lemurs face exceptionally high risks of population declines and extirpation. We examined how short-term land cover changes within a fragmented landscape in southeastern Madagascar impacted the density of lemur species. Using line transects, we assessed density changes in nine lemur species across five forest fragments. Diurnal surveys were conducted monthly from 2015 to 2019 on 35 transects (total effort = 1268 km). Additionally, 21 transects were surveyed nocturnally in 2015 and 2016 (total effort = 107.5 km). To quantify forest cover changes, we generated land use/land cover (LULC) maps from Sentinel-2 imagery using supervised classification for each year. For the LULC maps, we overlayed species-specific buffers around all transects and calculated the proportion of land cover classes within them. We observed declines in the annual densities of four diurnal and cathemeral lemur species between 2015 and 2019, with species-specific declines of up to 80% (<i>Varecia variegata</i>). While the density of two nocturnal species decreased, one increased fivefold (<i>Cheirogaleus major</i>) between 2015 and 2016. By 2019, Grassland was the dominant land type (50%), while Paddy Fields had the smallest coverage (1.03%). Mature Agricultural Land increased the most (63.37%), while New Agricultural Land decreased the most (–66.36%). Unexpectedly, we did not find evidence that higher forest cover supported a higher lemur population density within sampled areas, but we found support for the negative impact of degraded land cover types on three lemur species. Our study underscores the urgent need to address land-use changes and their repercussions for primate populations in tropical ecosystems. The diverse responses of lemur species to modified habitats highlight the complexity of these impacts and emphasize the importance of targeted conservation efforts.</p>","PeriodicalId":7662,"journal":{"name":"American Journal of Primatology","volume":"87 1","pages":""},"PeriodicalIF":2.0000,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajp.23615","citationCount":"0","resultStr":"{\"title\":\"Losing lemurs: Declining populations and land cover changes over space and time\",\"authors\":\"Pamela R. Narváez-Torres, Nicola K. Guthrie, Typhenn A. Brichieri-Colombi, Cressant P. Razafindravelo, Zachary S. Jacobson, Fredo Tera, Daniel V. Rafidimanana, Zé-Elinah Rahasivelo, Melody A. Petersen, Hasinala Ramangason, Lea Randall, Jana M. McPherson, Cynthia L. Frasier, Axel Moehrenschlager, Sheila M. Holmes, Edward E. Louis Jr., Steig E. Johnson\",\"doi\":\"10.1002/ajp.23615\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Forest loss and degradation due to land cover changes imperil biodiversity worldwide. Subtropical and tropical ecosystems experience high deforestation rates, negatively affecting species like primates. Madagascar's endemic lemurs face exceptionally high risks of population declines and extirpation. We examined how short-term land cover changes within a fragmented landscape in southeastern Madagascar impacted the density of lemur species. Using line transects, we assessed density changes in nine lemur species across five forest fragments. Diurnal surveys were conducted monthly from 2015 to 2019 on 35 transects (total effort = 1268 km). Additionally, 21 transects were surveyed nocturnally in 2015 and 2016 (total effort = 107.5 km). To quantify forest cover changes, we generated land use/land cover (LULC) maps from Sentinel-2 imagery using supervised classification for each year. For the LULC maps, we overlayed species-specific buffers around all transects and calculated the proportion of land cover classes within them. We observed declines in the annual densities of four diurnal and cathemeral lemur species between 2015 and 2019, with species-specific declines of up to 80% (<i>Varecia variegata</i>). While the density of two nocturnal species decreased, one increased fivefold (<i>Cheirogaleus major</i>) between 2015 and 2016. By 2019, Grassland was the dominant land type (50%), while Paddy Fields had the smallest coverage (1.03%). Mature Agricultural Land increased the most (63.37%), while New Agricultural Land decreased the most (–66.36%). Unexpectedly, we did not find evidence that higher forest cover supported a higher lemur population density within sampled areas, but we found support for the negative impact of degraded land cover types on three lemur species. 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Losing lemurs: Declining populations and land cover changes over space and time
Forest loss and degradation due to land cover changes imperil biodiversity worldwide. Subtropical and tropical ecosystems experience high deforestation rates, negatively affecting species like primates. Madagascar's endemic lemurs face exceptionally high risks of population declines and extirpation. We examined how short-term land cover changes within a fragmented landscape in southeastern Madagascar impacted the density of lemur species. Using line transects, we assessed density changes in nine lemur species across five forest fragments. Diurnal surveys were conducted monthly from 2015 to 2019 on 35 transects (total effort = 1268 km). Additionally, 21 transects were surveyed nocturnally in 2015 and 2016 (total effort = 107.5 km). To quantify forest cover changes, we generated land use/land cover (LULC) maps from Sentinel-2 imagery using supervised classification for each year. For the LULC maps, we overlayed species-specific buffers around all transects and calculated the proportion of land cover classes within them. We observed declines in the annual densities of four diurnal and cathemeral lemur species between 2015 and 2019, with species-specific declines of up to 80% (Varecia variegata). While the density of two nocturnal species decreased, one increased fivefold (Cheirogaleus major) between 2015 and 2016. By 2019, Grassland was the dominant land type (50%), while Paddy Fields had the smallest coverage (1.03%). Mature Agricultural Land increased the most (63.37%), while New Agricultural Land decreased the most (–66.36%). Unexpectedly, we did not find evidence that higher forest cover supported a higher lemur population density within sampled areas, but we found support for the negative impact of degraded land cover types on three lemur species. Our study underscores the urgent need to address land-use changes and their repercussions for primate populations in tropical ecosystems. The diverse responses of lemur species to modified habitats highlight the complexity of these impacts and emphasize the importance of targeted conservation efforts.
期刊介绍:
The objective of the American Journal of Primatology is to provide a forum for the exchange of ideas and findings among primatologists and to convey our increasing understanding of this order of animals to specialists and interested readers alike.
Primatology is an unusual science in that its practitioners work in a wide variety of departments and institutions, live in countries throughout the world, and carry out a vast range of research procedures. Whether we are anthropologists, psychologists, biologists, or medical researchers, whether we live in Japan, Kenya, Brazil, or the United States, whether we conduct naturalistic observations in the field or experiments in the lab, we are united in our goal of better understanding primates. Our studies of nonhuman primates are of interest to scientists in many other disciplines ranging from entomology to sociology.