Use of Descriptors of Ecosystem Functioning for Monitoring a National Park Network: A Remote Sensing Approach

Abstract

Baseline assessments and monitoring of protected areas are essential for making management decisions, evaluating the effectiveness of management practices, and tracking the effects of global changes. For these purposes, the analysis of functional attributes of ecosystems (i.e., different aspects of the exchange of matter and energy) has advantages over the traditional use of structural attributes, like a quicker response to disturbances and the fact that they are easily monitored through remote sensing. In this study, we described the spatiotemporal patterns of different aspects of the ecosystem functioning of the Spanish national parks and their response to environmental changes between 1982 and 2006. To do so, we used the NOAA/AVHRR-GIMMS dataset of the Normalized Difference Vegetation Index (NDVI), a linear estimator of the fraction of photosynthetic active radiation intercepted by vegetation, which is the main control of carbon gains. Nearly all parks have significantly changed during the last 25 years: The radiation interception has increased, the contrast between the growing and nongrowing seasons has diminished, and the dates of maximum and minimum interception have advanced. Some parks concentrated more changes than others and the degree of change varied depending on their different environmental conditions, management, and conservation histories. Our approach identified reference conditions and temporal changes for different aspects of ecosystem functioning, which can be used for management purposes of protected areas in response to global changes.

The Normalized Difference Vegetation Index (NDVI): unforeseen successes in animal ecology

“…These may be useful in conjunction with current studies of habitat selection and distribution to help understand future range requirements and restrictions for many species. This is particularly important to protected area planning and reserve design (Alcaraz-Segura et al 2009). For species currently in protected areas at the edges of their ranges, range shift predictions are fundamental to assessing whether they will be able to migrate and adapt.…”

Analysis of vegetation and land cover dynamics in north-western Morocco during the last decade using MODIS NDVI time series data

“…The Normalized Differenced Vegetation Index (NDVI; Sellers, 1985) as an indicator of vivid green vegetation and as a descriptor of ecosystem functions has proved to be very valuable for assessing ecological responses to environmental changes (Alcaraz-Segura et al, 2009;Pettorelli et al, 2005). NDVI-based approaches are widely used for monitoring vegetation activity using time series data sets (TSD) acquired by sensors aboard satellites with short revisit periods (Goward and Prince, 1995;Beck et al, 2006).…”

Satellite-Based Monitoring of Ecosystem Functioning in Protected Areas: Recent Trends in the Oak Forests (Quercus pyrenaica Willd.) of Sierra Nevada (Spain)

“…To explore the existence of inter-annual trends of ecosystem functioning during the 2001-2009 period in the oak forests of Sierra Nevada, we followed the methodology suggested by Alcaraz-Segura et al (2009b). In addition to the evaluation of long-term trends of the EVI_mean, we also evaluated the existence of significant trends within each of the 23 images (16-day periods) of the year by means of the Mann-Kendall trend test, a non-parametric trend test robust against non-normality, heterocedasticity, outliers, and serial dependence.…”

“…The use of satellitederived information allows for tracking the integrity of key ecological processes and their spatial and temporal variability with the advantage of using common protocols throughout the Earth (Dale & Beyeler, 2001). In this sense, several works have shown the ability of timeseries of satellite images to assess the existence of long-term ecosystem functional changes both at the regional (Baldi et al, 2008;Alcaraz-Segura et al, 2010b) and local (AlcarazSegura et al, 2008a;Alcaraz-Segura et al, 2008b;Alcaraz-Segura et al, 2009b;Cabello et al, Accepted) scales.…”