Land-cover change, people and jaguars – remote sensing or close sensing?

Posted 09/15/10

Biosphere reserves are important natural refuges many think of as pristine, untouched places, but this may be idyllic and often not the case. Humans are part of the ecosystems and in this particular Biosphere Reserve (Sierra de Manantlan) local communities depend on natural resources and are important decision makers. However, important key-stone species, like the jaguar (Panthera onca), are sensitive and need careful attention. Using remote sensing and GIS techniques, Oscar is monitoring the habitat conditions and changes that affect the jaguar's habitat and how this is linked to human presence. Re-zoning the biosphere reserve is one of the proposed management tools to overcome this delicate situation.

Oscar is a Mexican researcher born in Guadalajara, Jalisco, Mexico with a Biology degree from the University of Guadalajara (Mexico), a Master in Conservation Biology and Sustainable Development from the University of Wisconsin – Madison obtained in 1998, and a PhD in Environment and Resources (2008) also from UW-Madison.He is been doing research since then and in 2003 he became a full-time Professor and researcher. Now, in 2010, he had the opportunity to have a sabbatical year and his mind came immediately to Madison again. Why? Well, he knows the city, he likes it and also because his University in Guadalajara and the UW-Madison have common research projects and this was a good way to create even stronger relationships and also to learn from the SILVIS lab experience in Remote Sensing and its conservation applications in order to be able to apply the knowledge in his very own biosphere reserve management project.Oscar and his wife, Sarahy Contreras, are familiar with Madison since they spent three years back in 1996 here, when they did their Master and PhD. When the opportunity to take a sabbatical year and come to Madison as invited scientist came up, Oscar didn’t hesitate. He and his wife along with their 8 year old quadruplets drove to Madison for a week-long trip where they made many stops and organized games to keep their kids entertained. They will stay at UW Madison for one year. They like Madison and its people. They feel everybody is friendly and that it is an open-minded city.

Oscar Cardenas and his lovely family

He is here as an invited scientist from the University of Guadalajara, Mexico, and besides looking forward to learn, he wants to write a textbook on remote sensing application in environmental studies. Strengthening the relationships and links between his home university and the UW Madison is also a goal as well as doing some collaborative research with Volker Radeloff and other SILVIS lab members. He has some projects on land use changes and how it affects jaguar habitat. He hopes that one or two papers come out of his sabbatical in Madison.His main research interests are land-cover use change and its causes and consequences; to better understand ecological processes and biodiversity; help landscape planners and managers; and address in all its social issues. In his previous work he assessed land-cover change in Western Mexico and the impacts on biodiversity using remote-sensing and GIS tools to investigate the causes and consequences of deforestation and land-cover change. This is an important topic in Mexico because forests have decreased rapidly, although there’s no accurate estimate of deforestation rate in Mexico. The main changes in the land-cover are from forest to pasture and agriculture, and such deforestation has strong ramnifications for biodiversity, the loss of genetic variability, vectors of diseases and the decline of environmental services.The study area of Oscar’s research is the Sierra de Manantlan Biosphere Reserve and its area of influence. The assessment of jaguar habitat conditions the Biosphere Reserve is a part of his research interests and it is strongly connected to what he is investigating and teaching at the Universidad of Guadalajara.

Sierra de Manantlan biosphere reserve, Mexico

The assessment of jaguar habitat in the Sierra de Manantlan Biosphere Reserve and its influence zone caught Oscar’s attention because the jaguar is a key-stone species and consequently an indicator of the habitat ‘health’ since jaguars are associated with dense vegetation, but they are somewhat generalists, i.e., jaguars use a variety of habitats (forest, riparian areas, dense shrubs and cloud forests). This is important when one of your goals is to zone the biosphere accordingly to different final uses, since while jaguar is an adaptable species, it needs a healthy habitat to guarantee its presence in the long term.The main goals of this research project are: assess changes in potential jaguar habitat in the sierra over the last 30 years; evaluate potential jaguar movements in the region to habitat changes; and identify priority areas for jaguar conservation in region.The variables that are correlated to the jaguar’s habitat are water, vegetation, terrain and human activities and the available information is satellite imagery, cartographic information and different sources of information regarding the jaguar biology and habits (tracks, feces, photographs). Having all these materials available will lead to the creation of models and Oscar’s concerns for the moment are: Are these models useful and reliable? Are models ‘touching ground’? Are the models created to quantify biodiversity distribution or hot spots close to reality? What happens when one has to apply a habitat model to an area where hundreds or thousands of people live and suddenly those models are not effective because the area you propose to conserve is already inhabited? Should all the people be removed out of the area, or should we incorporate them into the model so we can propose something more real? Are protected areas really helping to conserve biodiversity and natural resources if they keep leaving humans out? Once again, the human factor caught Oscar’s attention since land owners and local communities are very important in landscape planning because they are the ones who make decisions and who need the resources to subsist and so they should be included in the model as well.The current research and project is a work in progress and for now the main conclusions are that this kind of studies might lead to changes in the conservation policies and strategies that ultimately could result in a proposal for rezoning the Sierra de Manantlan Biosphere Reserve and get the government involved in the region’s natural resources conservation.”

Story by Patricia Alexandre