- مبلغ: ۸۶,۰۰۰ تومان
- مبلغ: ۹۱,۰۰۰ تومان
The impact of extensive changes in land use and climate on species has led to an increasing focus on large-scale conservation planning. However, these plans are often static conservation prescriptions set against a backdrop of rapidly changing environments, which suggests that large-scale information on threats can improve the functionality of planning efforts. Jaguars (Panthera onca) are the focus of a range-wide conservation strategy extending from Mexico to Argentina that consists of jaguar conservation units (JCUs) and modeled corridors. Recent deforestation is a major threat to jaguar populations, but forest loss has not been systematically assessed across the entire jaguar network. In this study, we quantified the amount and rate of deforestation in JCUs and corridors between 2000 and 2012. JCUs lost 37,780 km2 forest (0.93%) at an increasing rate of 149.2 km2 yr−2 , corridors lost 45,979 km2 (4.43%) at a decreasing rate of 40.1 km2 yr−2 , and levels of forest fragmentation increased in corridors. Protected sections of JCUs and corridors lost less forest than unprotected sections, suggesting efforts to increase protected status of jaguar conservation areas are warranted. Higher deforestation in corridors indicates difficulties in maintaining connectivity of jaguar populations, and suggests the need for increased engagement with communities within corridor landscapes. Assessment of spatial variability of anthropogenic threats within the jaguar network may improve jaguar conservation by informing network prioritization and function.
4.1. Forest change analysis Our results demonstrate that jaguar corridors are experiencing high rates of deforestation and fragmentation of forest. Numerous jaguar core areas (JCUs) also experienced substantial forest loss, and JCUs demonstrated accelerating forest loss between 2000 and 2012. These forest loss rates and increased fragmentation of forests were generally higher in Central America and the southern edge of the jaguar range, where JCUs tend to be smaller, which suggests that long-term viability of some core areas for jaguars may be threatened. Compared to JCUs, forest loss was higher in corridors for both protected and unprotected sites, suggesting that human pressure on remaining forest in corridors is high regardless of protection status. This finding is alarming, considering that maintaining connectivity of jaguar populations across the range is one of the key goals for their conservation (Rabinowitz and Zeller, 2010; Zeller et al., 2013), and that work on determining the functionality of jaguar corridors forms the backbone of much recent research (Cuyckens et al., 2014; Petracca et al., 2014; Rodríguez-Soto et al., 2013; Silveira et al., 2014; Zeller et al., 2011). Given their substantial movement capabilities, jaguars may be able to move across some types of non-forested habitat during dispersal, and therefore minor loss of forest may not always lead to reduced connectivity. However, jaguars are often absent from smaller forest patches (Thornton et al., 2011; Urquiza-Haas et al., 2009), persist better in areas of more forest cover, and are vulnerable to increased human persecution in less forested and more fragmented landscapes (De Angelo et al., 2013), strongly suggesting that forest loss in corridors will be problematic for jaguar connectivity and the persistence of jaguar residents within corridor landscapes. Therefore, these results suggest that increased engagement with communities in key corridors is needed to maintain connectivity for jaguars in the face of rapid land-use change across the jaguar's range. For example, working with communities to minimize human-wildlife conflict, reduce forest loss, or protect private