Reviewing the Use of Resilience Concepts in Forest Sciences.

Purpose of 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, synthesizing 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 socioeconomic 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.

High SNP diversity in the non-toxic indigenous Jatropha curcas germplasm widens the potential of this upcoming major biofuel crop species.

BACKGROUND AND AIMS: Jatropha curcas (jatropha) is an oil crop cultivated in (sub)tropical regions around the world, and holds great promise as a renewable energy source. However, efforts to fully commercialize jatropha are currently hampered by the lack of genetic diversity in the extant breeding germplasm, and by the toxicity of its seeds meaning that its seed cake cannot be used as a protein source in animal feed, among other constraints. In Mexico, the species' native range, there are jatropha plants whose seeds are used to prepare traditional meals. This non-toxic jatropha 'type' is considered to harbour low genetic variation due to a presumed domestication bottleneck and therefore to be of limited breeding value; yet, very little is known regarding its origin and genetic diversity. METHODS: Using genotyping-by-sequencing (GBS), we extensively genotyped both indigenous toxic and non-toxic jatropha collected along roads and home gardens throughout southern Mexico. KEY RESULTS: Single nucleotide polymorphism diversity in non-toxic jatropha is relatively high, particularly in northern Veracruz state, the probable origin of this germplasm. Genetic differences between toxic and non-toxic indigenous genotypes are overall quite small. A a genome-wide association study supported a genomic region (on LG 8, scaffold NW_012130064), probably involved in the suppression of seed toxicity. CONCLUSIONS: Conservation actions are urgently needed to preserve this non-toxic indigenous, relatively wild germplasm, having potential as a fuel feedstock, animal feed and food source among other uses. More generally, this work demonstrates the value of conservation genomic research on the indigenous gene pool of economically important plant species.

Mitochondrial transcription factor A (TFAM) shapes metabolic and invasion gene signatures in melanoma.

Mitochondria are central key players in cell metabolism, and mitochondrial DNA (mtDNA) instability has been linked to metabolic changes that contribute to tumorigenesis and to increased expression of pro-tumorigenic genes. Here, we use melanoma cell lines and metastatic melanoma tumors to evaluate the effect of mtDNA alterations and the expression of the mtDNA packaging factor, TFAM, on energetic metabolism and pro-tumorigenic nuclear gene expression changes. We report a positive correlation between mtDNA copy number, glucose consumption, and ATP production in melanoma cell lines. Gene expression analysis reveals a down-regulation of glycolytic enzymes in cell lines and an up-regulation of amino acid metabolism enzymes in melanoma tumors, suggesting that TFAM may shift melanoma fuel utilization from glycolysis towards amino acid metabolism, especially glutamine. Indeed, proliferation assays reveal that TFAM-down melanoma cell lines display a growth arrest in glutamine-free media, emphasizing that these cells rely more on glutamine metabolism than glycolysis. Finally, our data indicate that TFAM correlates to VEGF expression and may contribute to tumorigenesis by triggering a more invasive gene expression signature. Our findings contribute to the understanding of how TFAM affects melanoma cell metabolism, and they provide new insight into the mechanisms by which TFAM and mtDNA copy number influence melanoma tumorigenesis.

Allometry and evaluation of in situ optical LAI determination in Scots pine: a case study in Belgium.

We evaluated several optical methods for in situ estimation of leaf area index (LAI) in a Belgian Scots pine (Pinus sylvestris L.) stand. The results obtained were compared with LAI determined from allometric relationships established in the same stand. We found high correlations between branch cross-sectional area, diameter at breast height (DBH) and basal area as dependent variables, and leaf mass, needle area and crown projection as independent variables. We then compared LAI estimated by allometry with LAI determined by three optical methods (LAI-2000, TRAC and digital hemispherical photography) both before and after corrections for blue light scattering, clumping and non-leafy material. Estimates of stand LAI of Scots pine ranged from 1.52 for hemispherical photography to 3.57 for the allometric estimate based on DBH. There was no significant difference (alpha = 0.01) between the allometric LAI estimates and the optical LAI values corrected for blue light scattering, clumping and interception by non-leafy material. However, we observed high sensitivity of the optical LAI estimates to the various conversion factors, particularly to the clumping factor, indicating the need for caution when correcting LAI measured by optical methods.