Región Terrestre Prioritaria Corredor biológico Ajusco-Chichinautzin biológica y por la gran cantidad de agua que nos proporciona, Greenpeace. This “Conservation Land” is a protected natural reserve that belongs to the “ Corredor Biológico Ajusco-Chichinautzin” one of the world’s primary nature. Área de Protección de Flora y Fauna Corredor Biológico Chichinautzin. .. Studies conducted on the Pelado Volcano (Sierra del Ajusco mountain range).
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Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the biolgcio community.
Quercus castanea is an oak species with characteristics of foundation species beyond presenting a wide geographical distribution and being a dominant element of Mexican temperate forests.
In this study, we analyzed the influence of population He and individual HL genetic diversity of Q. Specifically, we studied the composition, richness S and density of leaf-mining moths Lepidoptera: Tischeridae, Citheraniidaegall-forming wasps Hymenoptera: Cynipidaeand canopy parasitoids of Q.
In total, 22 endophagous insect species belonging to three orders Hymenoptera, Lepidoptera, and Diptera and 20 parasitoid species belonging to 13 families were identified. In general, we observed that the individual genetic diversity of the host plant HL has a significant positive effect on the S and density of the canopy endophagous insect communities.
In contrast, He has a significant negative effect on the S of endophagous insects. Additionally, indirect effects of HL were observed, affecting the S and density of parasitoid insects.
Our results suggest that genetic variation in foundation species can be one of the most important factors governing the dynamics of tritrophic interactions that involve oaks, herbivores, and parasitoids. An important question in modern ecology is how genetic variation within dominant species can be an important driver of ecological processes Whitham et al.
In this sense, an increasing number of reports have documented the effect of intra-specific genetic variation within foundation species on their associated communities. There is an emphasis on foundation species, which are a small subset of the total species in an ecosystem, because it has been suggested that they should capture most of the variation in the community structure and ecosystem processes.
Additionally, it could be nearly impossible to perform the studies of all species in the system had to be studied Whitham et al. Studies performed with this perspective suggest that the genetics of the foundation species can have strong organizational effects at the community and ecosystem levels see review Whitham et al. Canopy arthropod communities have been widely used to evaluate the influence of the genetic diversity of host plants on their associated communities Wimp et al.
In particular, endophagous insects include gall-forming wasps Cynipidae and leaf mining moths Wimp et al. This preference is probably because they are species with specific organ and tissue specialization Stone et al. To date, most the studies in the field of community genetics have analyzed the influence of genetic diversity and similarity on host plant communities. In particular, these studies have reported that species diversity increases as the genetic diversity of host plant populations increases Dungey et al.
Several studies have demonstrated that an increase in the host plant genetic diversity can generate changes in their morphology Lambert et al. These characteristics constitute a wider array of resources and conditions that can be used by their associated communities. On the other hand, similarities in host plant communities have been explained as due to genetically similar host plants expressing similar physical, chemical, and phenological characteristics Bangert and Whithamsuggesting that genetic differentiation through the geographic distribution of host plants can result in variation in the associated communities Bangert et al.
In addition, it has been suggested that the ecological relevance of host plant intra-specific genetic diversity can have a cascading effect Abrahamson ; Whitham et al.
In particular, galls induced by cynipid wasps are structures that have extraordinary ecological value because the host communities are structured in several trophic levels. These communities sometimes form very complex networks that consist of gall inductor, parasitoid, and inquiline insects Askew Particularly, gall wasps are frequently associated with a diverse parasitoid community.
In these communities, the majority of the associated parasitoids only attack oak gall wasps Askew ; Stone et al. However, information about the effects of the foundation host plant genetic diversity on this trophic level is scarce. Parasitoids also play a major role in regulating their insect host populations.
Scientific evidence has demonstrated that predators depend on herbivores. The distribution, abundance, and performance of parasitoids and predators should also somewhat depend on the quality of their host plants Giles et al. If there is high variation among plant genotypes for predation Fritzthere could be a heritable plant trait that is subject to natural selection Hare In this sense, Whitham et al. Therefore, tritrophic-level interactions represent a good model for examining the interacting species and ecosystem processes in which the direct and indirect effects of plant genetics are analyzable Price Considering that natural communities are complex ecological systems with structures and functions based on the interaction of different factors Bailey and Whithammultifactorial studies that include genetic factors and at least one ecological factor may be useful.
Oaks are dominant elements of forest canopies. These trees have a wide geographical distribution and are involved in important ecosystem processes, such as nutrient recycling and water balance Madritch and Hunter This information inspires us to think that most oak species have attributes of foundation species.
Moreover, oaks have high genetic diversity levels as a result of their life-history characteristics e. However, few studies have evaluated the influence of the host oak species genetic diversity on canopy arthropod communities.
Furthermore, it is unknown whether the oak genetic diversity may indirectly extend to higher trophic levels throughout the community. In habitats like oak forests, tree communities define the physical structure. For example, the forest canopy can be structurally more complex when it consists of more than one tree species or more host plant species individuals Sobek et al.
This complexity may result in greater availability of resources and conditions for insect communities. Our previous studies showed that Quercus castanea is an oak species involved in hybridization events with other red oaks Valencia-Cuevas et al.
In this study, we characterized the canopy endophagous insect community gall and miner insects and associated parasitoids to Q. These trees can be easily recognized in the field by their leaf characteristics.
The trees are located between 1, and 2, m a. They are frequently found in perturbed areas with a xerophytic shrub type of vegetation, which is also localized in mountain cloud forests Rzedowski and Rzedowski All chosen sites share the following common traits: Additionally, these areas present almost no local disturbance inside the forest because they are under Mexican protection standards.
This homogeneity among study sites could be useful to minimize the influence of environmental and spatial factors on insect endophagous and parasitoid communities that are associated with the Q. Spatial localization of six Q. In addition, the number of associated species with Q.
These species were as follows: Three transects of 1, m in each locality were created. The individuals 20 individuals per site that were morphologically ajusc-chichinautzin as pure Q. We found an increase in the individual and population genetic diversity of Q. The endophagous insect and parasitoid community structure associated with Q.
These individuals were 8—10 m 9. Tree canopies selected for sampling ajusco-chichjnautzin, as far as possible, spatially delimited from others by avoiding overlaps.
Insect communities were sampled using four randomly selected branches 50 leaves per branch in the middle part of the crown. Galls and mining leaves collected in each host tree were separated into the morphospecies level, placed in previously vouchered plastic containers e. Wasps and their parasitoids were identified to the finest taxonomic level. To evaluate the influence of the Q.
Corredor Biológico Chichinautzin
The HL is calculated as follows: This index varies between 0, when all loci are heterozygous, and 1, when all loci are homozygous. These parameters He and HL were used because they are frequently employed to evaluate the influence of both the population and individual genetic diversity on ajusxo-chichinautzin community structure e.
The species richness S of the canopy arthropod community and their associated parasitoids was estimated at the morpho-species level. Finally, a Tukey test was bilogico to determine significant differences between the infestation mean values among populations Zar We used a multiple regression approach to examine whether the Q.
Specifically, this analysis was useful to ajusco-chichinautzib the relative contribution from each factor on the species richness variation and endophagous and parasitoid insect density. We used a standard least squares model with partial type III sums of squares error structure and the HeHLhost density, and oak richness as our factors. Considering that endophagous insects are resources for parasitoids, we were interested in determining whether the density and species richness of endophagous insects can predict the density and species richness of the associated parasitoids.
Therefore, we used simple linear regressions. We constructed one structural equation model SEM to estimate the causal relationships between the host plant genetic diversity HeHL and ecological host plant density and red oak species richness and community S and density of endophagous and parasitoid insects variables. Based on a previous study Valencia-Cuevas et al.
For the model, we considered the host plant density and red oak species richness as independent variables. The dependent variables that we examined were the individual HL and population He genetic diversity, S and density of endophagous and parasitoid insects. The model was performed with the lavaan package for R Rosseel The endophagous insect community associated with Q.
Hymenoptera 18 speciesLepidoptera two speciesand Diptera two species, Appendix 2. In particular, the gall insect group Hymenoptera: Cynipidae was represented by eight genera Appendix 2.
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In terms of the species richness, the most important genus was Andricus at Meanwhile, the leaf mining insect group was represented by ajusco-chichinajtzin families, Diptera and Lepidoptera Appendix 2, Figure 2.
Canopy endophagous insects gall-forming wasps and leaf mining insects and parasitoid composition associated to Q. The parasitoid community was represented by 13 families Figure 2. The most important family in terms of the genus and species richness was Eulophidae Appendix 2. In addition, we found one inquiline wasp species was associated with gall inducted with Amphibolips hidalgoensis belonging to Synergus genus Cynipidae.
We also found two individuals who belong to Encyrtidae and one to Megaspilidae. Both families included hyperparasitoids species. Hyperparasitoids and inquiline insects were not included in the analysis. The mean ajuscoo-chichinautzin levels of endophagous insects were significantly different among the Q. We did not detect an infestation level pattern over the natural genetic diversity gradient that ajusco-chihcinautzin previously recognized in Q.
In general, our results showed that the Q.