Reviewing the use of resilience concepts in forest sciences

Purpose of the review Resilience is a key concept to deal with an uncertain future in forestry. In recent years, it has received increasing attention from both research and practice. However, a common understanding of what resilience means in a forestry context, and how to operationalise it is lacking. Here, we conducted a systematic review of the recent forest science literature on resilience in the forestry context, synthesising how resilience is defined and assessed. Recent findings Based on a detailed review of 255 studies, we analysed how the concepts of engineering resilience, ecological resilience, and social-ecological resilience are used in forest sciences. A clear majority of the studies applied the concept of engineering resilience, quantifying resilience as the recovery time after a disturbance. The two most used indicators for engineering resilience were basal area increment and vegetation cover, whereas ecological resilience studies frequently focus on vegetation cover and tree density. In contrast, important social-ecological resilience indicators used in the literature are socio-economic diversity and stock of natural resources. In the context of global change, we expected an increase in studies adopting the more holistic social-ecological resilience concept, but this was not the observed trend. Summary Our analysis points to the nestedness of these three resilience concepts, suggesting that they are complementary rather than contradictory. It also means that the variety of resilience approaches does not need to be an obstacle for operationalisation of the concept. We provide guidance for choosing the most suitable resilience concept and indicators based on the management, disturbance and application context

Comparative gut transcriptome analysis reveals differences between virulent and avirulent Russian wheat aphids, Diuraphis noxia

Citation: Anathakrishnan, R., Sinha, D. K., Murugan, M., Zhu, K. Y., Chen, M. S., Zhu, Y. C., & Smith, C. M. (2014). Comparative gut transcriptome analysis reveals differences between virulent and avirulent Russian wheat aphids, Diuraphis noxia. Retrieved from http://krex.ksu.eduThe Russian wheat aphid, Diuraphis noxia, is a destructive pest of cereal crops that exhibits virulence to D. noxia resistance genes in wheat. Therefore, it is important to identify D. noxia virulence factors. The insect gut, the primary site of defense to ingested toxins, is also a likely site of differential gene expression in virulent insects. Comparative analyses of gut transcriptomes from virulent and avirulent D. noxia can improve an understanding of aphid gut physiology and may reveal factors critical to compatible D. noxia-wheat interactions. A total of 4, 600 clones were sequenced from gut cDNA libraries prepared from avirulent (biotype 1) and virulent (biotype 2) D. noxia feeding on biotype 1-resistant wheat. A majority of the sequences (66% in biotype 1, 64% in biotype 2) matched those from the NR database. BLASTX analysis of sequences with the highest E-values revealed that 59% of the biotype 1 sequences matched those of the pea aphid, Acyrthosiphon pisum. However, only 17% of the biotype 2 sequences were similar to those of A. pisum. RT-qPCR expression analyses confirmed that the biotype 2 gut transcriptome differs significantly from that of biotype 1. A transcript coding the tRNA-Leu gene was significantly up-regulated in the biotype 2 transcriptome, strongly suggesting that leucine metabolism is a critical factor in biotype 2 survival. Many more transcripts encoding protease inhibitors occurred in the avirulent biotype 1 gut than in the gut of virulent biotype 2. However, more protease transcripts occurred in the biotype 2 gut than in the biotype 1 gut, suggesting that the avirulent biotype produces protease inhibitors in response to plant proteases. The virulent biotype 2 produces trypsin-like and chymotrypsin-like serine protease counter-defenses to overcome biotype 1-resistant plants