The Editor’s Choice for our April issue is “Dynamic feedbacks among tree functional traits, termite populations and deadwood turnover” by Guo, Tuo, Ci, Yan & Cornelissen. The findings of this article imply that tree functional composition, with variation in deadwood quality through decomposition time, can help to sustain termite populations and thereby forest carbon turnover.
Here Senior Editor, Amy Austin, explains the importance of this article, which she selected as this month’s Editor’s Choice!
This study was focused on how deadwood decomposes, and the importance of functional traits of different wood species and their interaction with termite consumption and diversity in a tropical forest in eastern China. The innovative conceptual model that is the backdrop for this study places functional traits of wood affecting carbon turnover in forest ecosystems in a context of interactions with time and key invertebrate consumers, the termites. The authors evaluated the importance of conservative and acquisitive traits of downed woody debris, placing the species along a Wood Economics Spectrum (WES) at the initial stages of decay, connecting this with termite activity and their contribution to mass loss (Figure 1). Next, they extended this model to later stages of decay, evaluating how termites, microbes and decay stage have affected these functional traits (often altering the position of the wood substrate along the WES as it becomes more palatable) and assessing the consequences for mass loss in later decomposition stages.
One of the main conclusions of this study is that the functional traits of deadwood species, which appear to change over the time course of woody decay, generate a range of deadwood quality that can help sustain stable termite populations and diversity in this subtropical forest. The interesting result is that the acquisitive WES wood is consumed early, and yet the mid-quality WES species have the highest termite abundance in the later stages of decomposition, strongly suggesting that the termites take advantage of early fungal decomposition of lignin which enhances the palatability of these species in more advanced stages of decay.
This study also considers the role of pangolins in this ecosystem…Just take a look at the pangolin cave! (Figure 2).
The Chinese pangolin (Manis pentadactyla) is an important vertebrate predator of termites in this ecosystem, and termites and ants constitute a large fraction of their diet. While not directly addressed in this study, the presence of these endangered animals at one of the study sites (Figure 3) suggests that the maintenance of stable termite populations may be a critical component for this species’ conservation. Taken together, the availability of diverse wood substrates may be an important vector for maintaining viable pangolin populations in this protected area. Further studies are clearly needed to elucidate the connections!
An important implication of this study for plant ecology is the movement up the food chain beyond initial functional traits of downed woody debris. The intricate plant-microbial invertebrate connections demonstrated here reveal that the complex nature of plant traits, especially after senescence, have yet to be fully appreciated. The dynamic feedbacks generating stability and diversity of invertebrate consumers with possible knock-on effects for predators clearly needs to be incorporated into our conceptual models of ecosystem functioning and suggests that added attention should be paid to the potential impacts of these aspects of plant biodiversity loss in terrestrial ecosystems.
Amy Austin Senior Editor, Journal of Ecology
You can read the full article by Guo et al. here: Dynamic feedbacks among tree functional traits, termite populations and deadwood turnover