I am currently finishing my undergraduate degree and have developed my Course Conclusion Work aiming to understand how dispersal patterns are affected by supra-annual seed fragmentation and reproduction in an area of semideciduous tropical forest in the state of Quintana Roo, Mexico. Using data collected by Melo et al., 2010 I analyzed the effective diversity of the region and built GLM’s to indicate the relationship between the independent (fragment area and year) and dependent variables (Hills diversity in its three exponents). The results found demonstrate that only dispersed seeds were influenced by supra-annual seed fragmentation and reproduction, and that this influence was positive for abiotic dispersion syndromes in Medium and Small fragments (<30 Ha and <3 Ha) as well as for the syndrome zoochoric in the Medium-sized fragments (see Figure 1 below). Our results, together with those previously discovered for this area, demonstrate and exemplify the current discussion on the effects of fragmentation (see Fletcher et al., 2019 and Fahrig et al., 2019 to get the point), where for the same region and dataset, we can see a negative effect of fragmentation mainly on the size of dispersed seeds, with larger seeds having a negative effect on the size of the fragments, while our results highlight a positive effect on the diversity in general of dispersed seeds. Indicating that the effects of fragmentation are indeed complex and need ample care to be generalized (see Rybicki et al., 2020 para ter outros exemplos disso)
Fig 1 It can be seen the relationship of each exponent of Hills with the origin (Local or Dispersed), dispersion syndrome (Abiotic or Zoochoric), fragmentation (Size of fragments) and seed overproduction (Year), with the medium and small fragment influencing positively the diversity of dispersed seeds.
With the guidance of Felipe Melo and Lucas Alencar, I am building my pre master’s project to be submitted to the postgraduate program in Ethnobiology and Conservation at the Federal Rural University of Pernambuco - UFRPE. The focus of the project is the construction of the Forest Security Index (ISF) for the Caatinga as the first chapter and, later, its application in the identification of spatial correlations between forest security and socioeconomic factors, mainly poverty for the region. Therefore, we are trying to understand how this index should be built. So far, we have identified that the main variables are within three axes: Forest, Access and Benefits, which measure, respectively, the existence and quantity of the forest in the region, the people’s access to the benefits of the forest and the continuity of the security status or insecurity from the amount of benefits that are removed from the location (see figure 2 for better understanding). With them in hand, the ISF will be built from the analysis of principal components and we will identify the spatial correlations using the cluster clustering method. We hope that with the result, we can reaffirm the need to look at the Caatinga not only aiming to identify chronic disturbances but also identifying where the population, highly dependent on forest resources for survival, is more vulnerable to inhuman conditions.
Fig 2 - Illustrative image of the main variables and interactions between the availability of forest resources (exemplified in the image by the forest in the center), the population’s access to that resource, thereby obtaining a benefit (the arrows) and the population that receives the benefit and is actively responsible by changes in the amount of benefits withdrawn (people).
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- January 1, 0001
- 3 minute read, 582 words
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