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Opuntia in México: identifying priority areas for conserving biodiversity in a multi-use landscape.

Illoldi-Rangel P, Ciarleglio M, Sheinvar L, Linaje M, Sánchez-Cordero V, Sarkar S - PLoS ONE (2012)

Bottom Line: Opuntia conservation in México require the management of large areas of land for multiple uses.The multi-criteria analyses identified priority areas and organized them in large contiguous blocks that can be effectively managed.A high level of connectivity was established among the prioritized areas resulting in the enhancement of possible modes of plant dispersal as well as only a small number of blocks that would be recommended for conservation management.

View Article: PubMed Central - PubMed

Affiliation: Biodiversity and Biocultural Conservation Laboratory, Section of Integrative Biology, University of Texas, Austin, Texas, United States of America. patz30@gmail.com

ABSTRACT

Background: México is one of the world's centers of species diversity (richness) for Opuntia cacti. Yet, in spite of their economic and ecological importance, Opuntia species remain poorly studied and protected in México. Many of the species are sparsely but widely distributed across the landscape and are subject to a variety of human uses, so devising implementable conservation plans for them presents formidable difficulties. Multi-criteria analysis can be used to design a spatially coherent conservation area network while permitting sustainable human usage.

Methods and findings: Species distribution models were created for 60 Opuntia species using MaxEnt. Targets of representation within conservation area networks were assigned at 100% for the geographically rarest species and 10% for the most common ones. Three different conservation plans were developed to represent the species within these networks using total area, shape, and connectivity as relevant criteria. Multi-criteria analysis and a metaheuristic adaptive tabu search algorithm were used to search for optimal solutions. The plans were built on the existing protected areas of México and prioritized additional areas for management for the persistence of Opuntia species. All plans required around one-third of México's total area to be prioritized for attention for Opuntia conservation, underscoring the implausibility of Opuntia conservation through traditional land reservation. Tabu search turned out to be both computationally tractable and easily implementable for search problems of this kind.

Conclusions: Opuntia conservation in México require the management of large areas of land for multiple uses. The multi-criteria analyses identified priority areas and organized them in large contiguous blocks that can be effectively managed. A high level of connectivity was established among the prioritized areas resulting in the enhancement of possible modes of plant dispersal as well as only a small number of blocks that would be recommended for conservation management.

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Plan A. The existing protected areas are shown in black.The additional selected areas are in gray.
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pone-0036650-g004: Plan A. The existing protected areas are shown in black.The additional selected areas are in gray.

Mentions: If no spatial criteria were used (the “” solution in the discussion below), all targets of representation for all species can be achieved in 133 570 new cells, that is, cells outside the existing protected areas. Such a solution has 10 221 clusters (or connected components). When spatial criteria were used, three separate nominal conservation plans were formulated. Plan A incorporated the minimization of area and maximization of compactness with equal weights. Plan B gave a three-fold preference to the former. Plan C included these criteria with equal weights but also incorporated achieving connectivity with a relative weight of one-half compared to the other two criteria. For each plan, two different solutions (labeled“1” and “2”) were obtained using different starting points for the search. Figure 4 shows the solution or conservation area network selected under Plan A with the least area; Figure 5 is the corresponding map for Plan B. Figure 6 is the map with highest connectivity for Plan C. Table 2 gives the number of cells, shape value (the perimeter–to–area ratio), and the number of clusters. Finally, all plans require about one-third of México's total area to be put under conservation. Table 3 shows the extent to which the major vegetation types of México were included in the different plans. It did not come as a surprise that the dominant vegetation type, under all plans, was xeric scrubland since these are assemblages typically dominated by Opuntia species. More pertinent to this study was the result that the next most common vegetation type consisted of agricultural and forestry lands. Since these are subject to intensive human use, their prevalence underscores the point being emphasized here, that Opuntia conservation areas should not be conceptualized as regions of strict human exclosure. Rather, both strictly protected areas for the conservation of microendemics, and management programs admitting human use for widely distributed species should be devised and should focus only on the long-term persistence of Opuntia species. For example, Figure 7 shows the agricultural and forestry lands incorporated into Plan C1. All plans included substantial areas of oak, pine, and deciduous forests, which were not intuitively expected until the performance of this analysis.


Opuntia in México: identifying priority areas for conserving biodiversity in a multi-use landscape.

Illoldi-Rangel P, Ciarleglio M, Sheinvar L, Linaje M, Sánchez-Cordero V, Sarkar S - PLoS ONE (2012)

Plan A. The existing protected areas are shown in black.The additional selected areas are in gray.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3351470&req=5

pone-0036650-g004: Plan A. The existing protected areas are shown in black.The additional selected areas are in gray.
Mentions: If no spatial criteria were used (the “” solution in the discussion below), all targets of representation for all species can be achieved in 133 570 new cells, that is, cells outside the existing protected areas. Such a solution has 10 221 clusters (or connected components). When spatial criteria were used, three separate nominal conservation plans were formulated. Plan A incorporated the minimization of area and maximization of compactness with equal weights. Plan B gave a three-fold preference to the former. Plan C included these criteria with equal weights but also incorporated achieving connectivity with a relative weight of one-half compared to the other two criteria. For each plan, two different solutions (labeled“1” and “2”) were obtained using different starting points for the search. Figure 4 shows the solution or conservation area network selected under Plan A with the least area; Figure 5 is the corresponding map for Plan B. Figure 6 is the map with highest connectivity for Plan C. Table 2 gives the number of cells, shape value (the perimeter–to–area ratio), and the number of clusters. Finally, all plans require about one-third of México's total area to be put under conservation. Table 3 shows the extent to which the major vegetation types of México were included in the different plans. It did not come as a surprise that the dominant vegetation type, under all plans, was xeric scrubland since these are assemblages typically dominated by Opuntia species. More pertinent to this study was the result that the next most common vegetation type consisted of agricultural and forestry lands. Since these are subject to intensive human use, their prevalence underscores the point being emphasized here, that Opuntia conservation areas should not be conceptualized as regions of strict human exclosure. Rather, both strictly protected areas for the conservation of microendemics, and management programs admitting human use for widely distributed species should be devised and should focus only on the long-term persistence of Opuntia species. For example, Figure 7 shows the agricultural and forestry lands incorporated into Plan C1. All plans included substantial areas of oak, pine, and deciduous forests, which were not intuitively expected until the performance of this analysis.

Bottom Line: Opuntia conservation in México require the management of large areas of land for multiple uses.The multi-criteria analyses identified priority areas and organized them in large contiguous blocks that can be effectively managed.A high level of connectivity was established among the prioritized areas resulting in the enhancement of possible modes of plant dispersal as well as only a small number of blocks that would be recommended for conservation management.

View Article: PubMed Central - PubMed

Affiliation: Biodiversity and Biocultural Conservation Laboratory, Section of Integrative Biology, University of Texas, Austin, Texas, United States of America. patz30@gmail.com

ABSTRACT

Background: México is one of the world's centers of species diversity (richness) for Opuntia cacti. Yet, in spite of their economic and ecological importance, Opuntia species remain poorly studied and protected in México. Many of the species are sparsely but widely distributed across the landscape and are subject to a variety of human uses, so devising implementable conservation plans for them presents formidable difficulties. Multi-criteria analysis can be used to design a spatially coherent conservation area network while permitting sustainable human usage.

Methods and findings: Species distribution models were created for 60 Opuntia species using MaxEnt. Targets of representation within conservation area networks were assigned at 100% for the geographically rarest species and 10% for the most common ones. Three different conservation plans were developed to represent the species within these networks using total area, shape, and connectivity as relevant criteria. Multi-criteria analysis and a metaheuristic adaptive tabu search algorithm were used to search for optimal solutions. The plans were built on the existing protected areas of México and prioritized additional areas for management for the persistence of Opuntia species. All plans required around one-third of México's total area to be prioritized for attention for Opuntia conservation, underscoring the implausibility of Opuntia conservation through traditional land reservation. Tabu search turned out to be both computationally tractable and easily implementable for search problems of this kind.

Conclusions: Opuntia conservation in México require the management of large areas of land for multiple uses. The multi-criteria analyses identified priority areas and organized them in large contiguous blocks that can be effectively managed. A high level of connectivity was established among the prioritized areas resulting in the enhancement of possible modes of plant dispersal as well as only a small number of blocks that would be recommended for conservation management.

Show MeSH