Arthropod Diversity and Functional Importance in Old-Growth Forests of North America

Abstract

Old-growth forests have become rare in North America but provide habitat for unique assemblages of species that often are rare in younger forests. Insects and related arthropods reach their highest diversity in old-growth forests because of their stable moderate temperature and relative humidity and the rich variety of resources represented by high plant species richness and structural complexity. Old-growth arthropod assemblages typically are distinct from those in younger, managed forests. Major subcommunities include the arboreal community that is composed of a rich assemblage of herbivores, fungivores, and their associated predators and parasitoids that function to regulate primary production and nutrient fluxes, the stem zone community that includes bark-and wood-boring species and their associated predators and parasitoids that initiate the decomposition of coarse woody debris, and the forest floor community composed of a variety of detritivores, fungivores, burrowers, and their associated predators and parasitoids that are instrumental in litter decomposition. Insect outbreaks are relatively rare in old-growth forests, where the diversity of resources and predators limit population growth. In turn, insects contribute to plant diversity and limit primary production of host plant species, thereby promoting development of old-growth forest characteristics. Arthropods also provide important functions in decomposition and nutrient cycling that may be lost in younger, managed forests with limited provision of coarse woody debris and accumulated litter. Protection of remnant old-growth forests within the forest matrix may be particularly valuable for maintaining the diversity of plant and arthropod predators that can minimize outbreaks, thereby contributing to resilience to changing environmental conditions.

Multiscale drivers of carabid beetle (Coleoptera: Carabidae) assemblages in small European woodlands

“…Ancient forest patches usually support more diverse plant assemblages than recent ones, given their higher habitat heterogeneity (Brunet, 2007;Burrascano et al, 2018) and the longer time period available for accumulating forest specialist species (i.e., the species-time relationship; Almoussawi et al, 2020;Valdés et al, 2020). However, compared to plant species, arthropod species have received little attention with respect to species richness in ancient versus recent forest patches (Schowalter, 2017). Besides, to the best of our knowledge, only a few studies have compared the diversity patterns of such arthropod assemblages in different landscape mosaic contexts (e.g., De Smedt et al, 2018;Hendrickx et al, 2009).…”

Fauna activity on soils developing on dead logs in an ancient inland temperate rainforest of North British Columbia (Canada)

“…Forestry is one of the traditional industries in the upper Fraser area; fortunately, cedar timber is regarded as a low-value timber and at least some cedar stands were left behind during big-scale tree harvesting (Coxson et al 2012). It was showed that unmanaged, ancient forests throughout the world are hot spots for diversity of various groups of organisms, for example, canopy macrolichen (Radies et al 2009), soil microbial community (Gömöryová et al 2013), arthropods (Schowalter 2017) or small mammals (Sullivan et al 2001). Therefore, we can expect for high soil fauna diversity in ancient temperate rainforests, both in forest floor and log soils.…”

Pastagens cultivadas como modificadoras dos padrões ecológicos dos organismos edáficos

“…Os besouros consomem todo tipo de recurso alimentar, existindo espécies predadoras, herbívoras, brocadoras de sementes, galhadoras, polinizadoras e detritívoras (Schowalter, 2017). A maior densidade e dominância da ordem Coleoptera foram encontradas na área ocupada com Mombaça, a área com menor densidade e dominância foi a ocupada com B.…”