Differences Between Forest Type and Vertical Strata in the Diversity and Composition of Hymenpteran Families and Mymarid Genera in Northeastern Temperate Forests

Abstract

Most insects' assemblages differ with forest type and show vertical stratification. We tested for differences in richness, abundance and composition of hymenopteran families and mymarid genera between sugar maple (Acer saccharum) and white pine (Pinus strobus) stands and between canopy and understory in northeastern temperate forests in Canada. We used flight interception traps (modified malaise traps) suspended in the canopy and the understory in a split-split block design, with forest type as the main factor, forest stratum as the first split factor, and collection bottle location as the second split factor. Hymenopteran families and mymarid genera differed in their diversity depending on forest type and stratum. Both family and genera richness were higher in maple than in pine forests, whereas family richness was higher in the canopy and top bottles and generic richness was higher in the understory and bottom bottles. Multivariate analysis separated samples by forest type, vegetation stratum, and bottle location. Family composition showed 77% similarity between forest types and 73% between the canopy and understory. At the lower taxa level, mymarid genera showed only 47% similarity between forest types and 40% between forest strata, indicating vertical stratification and relatively high beta-diversity. Our study suggests that hymenopteran diversity and composition is strongly dependent on forest type and structure, making flying members of this order particularly vulnerable to forest management practices. It also shows that insect assemblage composition (especially at low-taxon levels), rather than relative abundance and richness, is the community attribute most sensitive to forest type and vertical stratification.

Patrones de variación espacial y temporal de los macroinvertebrados acuáticos en la Laguna de Tecocomulco, Hidalgo (México)

“…Los ejemplares colectados se separaron in situ del material abiótico y se fijaron en etanol al 70% para su preservación y posterior transporte al laboratorio, donde se realizó la separación y determinación taxonómica hasta nivel de familia empleando claves especializadas (Thorp & Covich, 2001;Merrit, Cummins & Berg, 2008;Krantz & Evans, 2009) con ayuda de un microscopio estereoscópico Zeiss modelo Stemi 1 000. La riqueza de táxones fue obtenida contando las familias por sitio y época, se modeló una curva de rarefacción basada en el número de muestras versus número acumulativo de familias de todo el periodo de estudio tal como se ha utilizado por Vance, Smith, Malcolm, Huber & Bellocq (2007), las curvas de rarefarección se generaron con el programa EstimateS 8.2.0 (Colwell, 2009), así también, se construyó la curva de acumulación de familias por muestra.…”

Vertical canopy gradient shaping the stratification of leaf‐chewer–parasitoid interactions in a temperate forest

“…Therefore, we might expect the stratification of herbivores and associated parasitoids to exist in temperate forests. However, studies of parasitoid stratification are also scarce and are often limited to surveys of adults (e.g., Compton, Ellwood, Davis, & Welch, 2000; Pucci, 2008; Stireman et al., 2012; Vance, Smith, Malcolm, Huber, & Bellocq, 2007), restricting our understanding of trophic links. Consequently, knowledge of the stratification of parasitoids and parasitism rates along a vertical gradient in a temperate forest remains limited.…”

Vertical stratification of selected Hymenoptera in a remnant forest of the Po Plain (Italy, Lombardy) (Hymenoptera: Ampulicidae, Crabronidae, Sphecidae)

“…Previous studies performed in temperate forests also showed a vertical stratification in the community composition of hymenopterans (Vance et al 2007;Pucci 2008;Sobek et al 2009;Ulyshen et al 2010Ulyshen et al , 2011. Vance et al (2007) found that, in northeastern temperate forests in Canada, Spheciformes are more common in the canopy than in the understory, suggesting that highly mobile hymenopterans may spend significant amounts of time foraging in this habitat. A similar result was found by Sobek et al (2009), who collected more cavity-nesting bees -including Spheciformes -in the canopy of a broadleaf forest in Germany.…”

“…Forest managers have often ignored the effects that certain silvicultural practices would have on the diversity of insects associated with higher strata of the forest. In recent years, improved methods to access canopies gave the opportunity to sample insects of this habitat (Basset et al 1997(Basset et al , 2003Vance et al 2007), showing that canopies can host some rarely collected or undescribed species (Floren & Schmidl 1999Thunes et al 2004;Vance et al 2007;Di Giovanni et al 2015).…”

“…Yet, only few studies have focused on highly mobile (and highly diverse) insects as dipterans or hymenopterans of the canopy of temperate forests (Preisser et al 1998;Sperber et al 2004;Thunes et al 2004;Vance et al 2007;Pucci 2008;Stireman 2008;Sobek et al 2009;Ulyshen et al 2010Ulyshen et al , 2011aUlyshen et al , 2011bBirtele & Hardersen 2012;Stireman et al 2012;Di Giovanni et al 2015). In this study, we analyzed the community composition of solitary wasps belonging to Ampulicidae, Crabronidae and Sphecidae (the three families of Apoidea Spheciformes present in Italy) of understory and canopy of the Natural Reserve of "Bosco della Fontana", a temperate plain forest in North Italy.…”