Chemical transformation of Quercus wood by Cetonia larvae (Coleoptera: Cetoniidae): An improvement of carbon and nitrogen available in saproxylic environments

Abstract

Forests make up the major percentage of terrestrial ecosystems and woody debris is recognised as an important long-term pool of forest carbon [29]. Despite being key to forest productivity, the understanding of how saproxylic organisms affect wood chemistry and organic matter stability during wood decomposition is still limited (see Refs. [47,50]. Among saproxylic insects, beetles make up the biggest part of saproxylic diversity and are primarily responsible for the mechanical breakdown of woody material [4], both directly, by tunnelling and feeding, and indirectly, through symbiotic relationships with fungi and other microorganisms that humify wood [45]. Many studies have shown increases in nutrient concentrations, especially nitrogen (N) and phosphorus (P), as wood decomposes [48]. A higher concentration of P and N than in surrounding soils was found in fresh earthworm casts [22], in freshly constructed termite mound materials [27], and in nests of wood ants [8]. Also, higher concentration of N and P than that of wood has been found in faeces of humivorous cetonid beetle larvae Pachnoda ephippiata [24,25], and in the faeces of the wood-feeding scarabaeid beetle larvae Osmoderma eremita [18] and Cetonia aurataeformis [31]. Moreover, numerous farmers from Africa, South America and Australia have long recognised the benefits of insects such as termites to crop production [48].

Nutrient Dynamics in Decomposing Dead Wood in the Context of Wood Eater Requirements: The Ecological Stoichiometry of Saproxylophagous Insects

“…The actions of insects and mites include bringing symbiotic fungi or soil into the wood environment, which may contribute to the nutritional enrichment of the internal dead wood environment (Ulyshen and Wagner 2013; Ulyshen 2016) but not to the wood itself. Similarly, the dead wood environment may be nutritionally enriched by the accumulation of loose organic material in tree hollows (Landvik et al 2016) or by the accumulation of the feces of saproxylophages (Chen and Forschler 2016;Sánchez et al 2017). Another source of nutritional enrichment may be the action of ants bringing nutrients in the form of harvested organisms and excreta from the outside environment (Pinkalski et al 2015).…”

Diversity and deadwood-based interaction networks of saproxylic beetles in remnants of riparian cloud forest

“…shade coffee) and commercial plantations, among others [6–8]. During wood degradation, saproxylic beetles fulfilling important ecological functions [6] as a result of their capability to rapidly transform the physical-chemical properties of the microenvironment in which they develop their life cycle, directly influencing soil fertility and therefore also other saproxylic taxa [9–11].…”

It takes a community to maintain a tree hollow: Food web complexity enhances decomposition and wood mould production

“…We found support for our second hypothesis that decomposition rates would be higher with greater food web complexity. As wood decomposes, mass is lost, and nitrogen and phosphorus concentrations increase (Sánchez et al, 2017; Ulyshen, 2015). Thus, there are two reasons to conclude that decomposition was greater in the complex community.…”

“…Litter decomposition and wood mould creation are interconnected, and laboratory research has found that beetle larvae ( Cetonia aurataeformi ) specialized on oak tree hollows can decompose polysaccharides in Quercus sp. wood producing frass with altered organic structure and higher concentration of nitrogen and phosphorus (Sánchez et al, 2017). Field studies have linked the presence of other beetle larvae, also specialized in tree hollows ( Cetoniidae sp.…”