Evaluation of ecosystem functioning in the Sierra Nevada National Park with the aid of remote sensing: basis for a monitoring system.
María del Pilar Águila Carricondo.
The monitoring of the ecosystem functioning of the Sierra Nevada Protected Area is a key aspect to know how its ecosystems function and vary both temporally and spatially and to be able to act according to the results. In this work, we describe the seasonal dynamics of the functioning of eight ecosystems in the Sierra Nevada (holm oak forest, high mountain scrubland, mid-mountain scrubland, grassland, pine forests on dolomites and Pinus sylvestris, coniferous reforestations and oak forests) and their spatio-temporal trends in the period 2001-2013. In order to carry out this analysis work, we used MODIS satellite images that contained information on the Enhanced Vegetation Index (EVI), a linear estimator of the photosynthetically active fraction absorbed by radiation, an excellent indicator of carbon gains. The most productive ecosystems are the oak forest and coniferous reforestation, and the least productive was the grassland. This ecosystem was the one with the highest sCv were oak groves and coniferous reforestations, and the least productive was pastureland. All the ecosystems underwent changes during the study period, but the ones that underwent the greatest changes were those located at higher elevations: grassland, high mountain scrubland and high and the coniferous reforestations. In addition, we found a regional pattern in the EVI trends experienced by the ecosystems. Thus, while in the western part of the park there were mostly negative trends, in the eastern part of the park, these were positive. The work carried out allowed us to detect changes in the ecosystems of the Sierra Nevada in the context of global change dependent on climatic factors (precipitation, temperatures, and presence of snow) and geographical factors, such as altitude and latitude.
Keywords: Regional Analysis, Global Change, Reference Conditions, Ecosystem Functioning, Enhanced Vegetation Index (EVI), Net Primary Productivity (NPP), Sierra Nevada, EVI Trends