Central-west and south of Mexico are particularly rich in oak species, coexisting from two to six species and generating gradients of oak diversity that could potentially affect community structure of canopy arthropods. We evaluated changes in canopy arthropod diversity of the Quercus laurina along a gradient of oak diversity in the central-west portion of the Trans-Mexican Volcanic Belt. Five study sites that represent an oak diversity gradient and, where Q. laurina is also widespread were selected. At each site, five mature trees of Q. laurina were randomly selected to collect canopy arthropods using fogging techniques. We assessed the effects of local climate variables on the oak community and the canopy arthropod diversity. We collected 7479 arthropods representing 1154 morphospecies grouped into 15 different orders. Differences in arthropod diversity, abundance and guild composition between oak communities were detected. The general pattern showed a highest richness and abundance of arthropods in Tequila volcano, which represented the site with the greatest diversity of oaks. A significant positive relationship between arthropod abundance and oak species diversity was found. Arthropod guild composition differed along the gradient of oak diversity. Local environmental variables were related with oak community, but did not explained canopy arthropod diversity. At the local scale, plant species richness is the main factor that determines the canopy arthropod abundance and richness of Q. laurina, affecting the structure and composition of arthropod guilds. We highlight the importance of conserving oak species because they represent key elements of temperate forest that harbor high arthropod diversity. Implications for insect conservation Our findings confirm that at the local scale, plant species richness is the main factor that determines the arthropod diversity associated with the canopy of Quercus laurina, affecting trophic levels and the composition of arthropod guilds. Therefore, the oak species diversity in temperate forests is a key factor to harbor and preserving the diversity of canopy arthropods in temperate ecosystems.

Background and Aims: Environmental factors can interact with plant life history to determinate the reproductive strategies of adult plants and seedling recruitment. We expect that widely distributed tree species produce heavier seed and with greater variation in seed size than shrubs of restricted geographic distribution. We also predict that widely distributed tree species should be capable to germinate and develop under variable range of light conditions, while sun-adapted shrubs should germinate and develop better under high light intensity. We used as models two congeneric species of Fabaceae. Copaifera langsdorffii is a widely distributed arboreal species and C oblongifolia is a shrub with restricted distribution. Methods: Seeds were collected from two plant species in a Cerrado vegetation area, northern Minas Gerais, Brazil. The effects of light available on seed germination and seedling development was conducted in a germination chamber with controlled photoperiod, temperature and light intensity.Key results: The widely distributed tree (C. langsdorffii) had greater seed mass than the shrub (C. oblongifolia). Seeds of C. langsdorffii germinated faster under available high light, while the shrub C. oblongifolia seeds required less time to germinate under available low light and darkness. Under high light intensity, germination percentage of C. langsdorffii and C. oblongifolia seeds did not vary. However, seeds of the shrub showed a higher germination percentage under low light intensity and darkness. In general, seed mass showed a negative relationship with germination percentage, but this relationship varied in function of species and the availability of light. Copaifera langsdorffii seedlings had larger shoots and roots than C. oblongifolia. In contrast, the root:shoot ratio was higher in shrub than in tree species.Conclusions: Our results have important implications for understanding the patterns of distribution of two Copaifera species and explain the ability of C. oblongifolia to colonize disturbed areas.

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