Rapid silviculture appraisal to characterise stand and determine silviculture priorities of community forests in Nepal

Published online: 7 September 2016Community forestry in Nepal is an example of a successful participatory forest management program. Developments in community forestry in four decades have focused on the social and governance aspects with little focus on the technical management of forests. This paper presents a silviculture description of community forests and provides silviculture recommendations using a rapid silviculture appraisal (RSA) approach. The RSA, which is a participatory technique involving local communities in assessing forests and silviculture options, is a simple and costeffective process to gather information and engage forest users in the preparation of operational plans that are relevant to their needs. The RSA conducted on selected community forests in Nepal’s Mid-hills region shows that forests are largely comprised of dominant crowns of one or two species. The majority of studied community forests have tree densities below 500 stems per hectare as a consequence of traditional forest management practices but the quality and quantity of the trees for producing forest products are low. Silviculture options preferred by forest users generally are those which are legally acceptable, doable with existing capacities of forest users and generate multiple forest products. For sustainable production of multiple forest products, the traditional forest management practices have to be integrated with silviculture-based forest management system.Edwin Cedamon, Ian Nuberg, Govinda Paudel, Madan Basyal, Krishna Shrestha, Naya Paude

Crown and regeneration responses to silviculture systems in Pine and Sal forests: preliminary results from silviculture trials in Mid-hills Nepal

Silviculture trial plots were established in Kavre and Lamjung districts by the EnLiFT Project (Enhancing livelihoods and food security through improved agroforestry and community forestry in Nepal) to examine stand response to selected silviculture systems – uniform shelterwood, selection system, and negative thinning and as a showcase to forest users for these silviculture systems. This paper analyses the extent of canopy gaps on these trial plots after one-year of application of silviculture treatments and regeneration development. Using crown photographs, crown cover was estimated and compared between silviculture systems. The analysis showed that rigid silviculture systems like shelterwood and selection systems created canopy gap larger than negative thinning in Pine plantations and the rate of natural regeneration was directly related with the canopy gap. However, in Shorea robusta-Castanopsis- Schima (Sal-Katus-Chilaune) forest, negative thinning created canopy gap larger than selection system due to removal of 4-D trees, majority of trees were Schima wallichii (Chilaune),which typically have large spreading crown. Although, it may be too early to conclude the relationship between regeneration development and canopy gap from the trial plots, it became clear that silviculture operations have significant role in promoting higher regeneration. Selection and shelterwood systems are better than current silviculture regime represented by negative thinning in this study.E. Cedamon, G. Paudel, M. Basyal, I. Nuberg and N. Paude

Canopy gaps and regeneration development in Pine and Sal Forests Silviculture Demonstration Plots in Midhills Nepal

Silviculture demonstration plots were established in Kavre and Lamjung districts by the EnLiFT Project to examine stand response to selected silviculture system ~ uniform shelterwood, selection system, and negative thinning and as a showcase to forest users for these silviculture system. This paper analysis the extent of canopy gaps on these demo plots after silviculture treatments and regeneration development one-year after treatment. Using crown photographs, crown covers are estimated and compared between silviculture systems. The analysis have shown that rigid silviculture systems like shelterwood and selection system can create significant canopy gaps than negative thinning in pine plantations and that the rate of natural regeneration is directly related with the canopy gaps. In Sal-Katus-Chilaune forest however, negative thinning created canopy gaps larger than selection silviculture demo plots due to removal of 4-D trees, majority are Chilaune trees, which typically have large spreading crown. Although conclusion from the demo plots at this stage may be too early to make on regeneration growth and canopy gap relationship, it is clear that silviculture operations have significant role in promoting higher rate regeneration growth and that rigid silviculture operations like selection and shelterwood systems are better than current silviculture regime represented by negative thinning in this study.Edwin Cedamon, Govinda Paudel, Madan Basyal, Ian Nuberg and Naya Paude

Genome sequencing reveals fine scale diversification and reticulation history during speciation in Sus

Background Elucidating the process of speciation requires an in-depth understanding of the evolutionary history of the species in question. Studies that rely upon a limited number of genetic loci do not always reveal actual evolutionary history, and often confuse inferences related to phylogeny and speciation. Whole-genome data, however, can overcome this issue by providing a nearly unbiased window into the patterns and processes of speciation. In order to reveal the complexity of the speciation process, we sequenced and analyzed the genomes of 10 wild pigs, representing morphologically or geographically well-defined species and subspecies of the genus Sus from insular and mainland Southeast Asia, and one African common warthog. Results Our data highlight the importance of past cyclical climatic fluctuations in facilitating the dispersal and isolation of populations, thus leading to the diversification of suids in one of the most species-rich regions of the world. Moreover, admixture analyses revealed extensive, intra- and inter-specific gene-flow that explains previous conflicting results obtained from a limited number of loci. We show that these multiple episodes of gene-flow resulted from both natural and human-mediated dispersal. Conclusions Our results demonstrate the importance of past climatic fluctuations and human mediated translocations in driving and complicating the process of speciation in island Southeast Asia. This case study demonstrates that genomics is a powerful tool to decipher the evolutionary history of a genus, and reveals the complexity of the process of speciation

Mutations in the autoregulatory domain of β-tubulin 4a cause hereditary dystonia.

Dystonia type 4 (DYT4) was first described in a large family from Heacham in Norfolk with an autosomal dominantly inherited whispering dysphonia, generalized dystonia, and a characteristic hobby horse ataxic gait. We carried out a genetic linkage analysis in the extended DYT4 family that spanned 7 generations from England and Australia, revealing a single LOD score peak of 6.33 on chromosome 19p13.12-13. Exome sequencing in 2 cousins identified a single cosegregating mutation (p.R2G) in the β-tubulin 4a (TUBB4a) gene that was absent in a large number of controls. The mutation is highly conserved in the β-tubulin autoregulatory MREI (methionine-arginine-glutamic acid-isoleucine) domain, highly expressed in the central nervous system, and extensive in vitro work has previously demonstrated that substitutions at residue 2, specifically R2G, disrupt the autoregulatory capability of the wild-type β-tubulin peptide, affirming the role of the cytoskeleton in dystonia pathogenesis