Forest Research Institute

About: Forest Research Institute is a facility organization based out in Dehra Dūn, India. It is known for research contribution in the topics: Population & Forest management. The organization has 5320 authors who have published 7625 publications receiving 185876 citations.

Molecular phylogeny based on six nuclear genes suggests that Echinococcus granulosus sensu lato genotypes G6/G7 and G8/G10 can be regarded as two distinct species.

Abstract: Tapeworms of the species complex of Echinococcus granulosus sensu lato (s. l.) are the cause of a severe zoonotic disease - cystic echinococcosis, which is listed among the most severe parasitic diseases in humans and is prioritized by the World Health Organization. A stable taxonomy of E. granulosus s. l. is essential to the medical and veterinary communities for accurate and effective communication of the role of different species in this complex on human and animal health. E. granulosus s. l. displays high genetic diversity and has been divided into different species and genotypes. Despite several decades of research, the taxonomy of E. granulosus s. l. has remained controversial, especially the species status of genotypes G6-G10. Here the Bayesian phylogeny based on six nuclear loci (7387 bp in total) demonstrated, with very high support, the clustering of G6/G7 and G8/G10 into two separate clades. According to the evolutionary species concept, G6/G7 and G8/G10 can be regarded as two distinct species. Species differentiation can be attributed to the association with distinct host species, largely separate geographical distribution and low level of cross-fertilization. These factors have limited the gene flow between genotypic groups G6/G7 and G8/G10, resulting in the formation of distinct species. We discuss ecological and epidemiological differences that support the validity of these species.

Structure and Function of Intra–Annual Density Fluctuations: Mind the Gaps

Abstract: Tree rings are natural archives of climate and environmental information with a yearly resolution. Indeed, wood anatomical, chemical and other properties of tree rings are a synthesis of several intrinsic, environmental factors, and interconnected processes acting during tree growth. In particular, Intra-Annual Density Fluctuations (IADFs) can be considered as tree-ring anomalies that can be used to better understand tree growth and to reconstruct past climate conditions with intra-annual resolution. However, the ecophysiological processes behind IADF formation, as well as their functional impact, remain unclear. Are IADFs resulting from a prompt adjustment to fluctuations in environmental conditions to avoid stressful conditions and/or to take advantage from favorable conditions? In this paper we discuss: (1) the influence of climatic factors on the formation of IADFs; (2) the occurrence of IADFs in different species and environments; (3) the potential of new approaches to study IADFs and identify their triggering factors. Our final aim is to underscore the advantages offered by network analyses of data and the importance of high-resolution measurements to gain insight into IADFs formation processes and their relations with climatic conditions, including extreme weather events.

Host tree and bark beetle interaction during a mass outbreak of Ips typographus in Norway1

Abstract: Outbreaks of the spruce bark beetle Ips typographus have caused great damage to the forest of Norway during the recent decade. About 5 million cubic meter of timber have been attacked. The outbreaks were initiated by extensive storm damages in 1969 and extreme drought during the years 1975–77. The most extensive damage occurred in regions with large continuous areas of spruce, on areas of high and medium site class and on geological formations with poor groundwater-retaining properties and thin soil. Reemergence and establishment of sister generations was an important part of the beetles repruduction biology. Brood density is regulated to reduce the degree of overpopulation, thereby preventing the collapse of the population due to food shortage. No correlation could be found between killed trees and occurrence of butt rot. None of 15 different criteria for tree growth and vitality could be used to distinguish between trees that were killed and those which survived attack. It is supposed that the decline in beetle population was a combined effect of cool and wet summer weather, which limited the flight activity of the beetle and restored the resistance of the trees to beetle attack, and an extensive control program where mass trapping of beetles in response to synthetic pheromone was an important part. Zusammenfassung Wechselwirkungen zwischen Wirtsbaum und Borkenkafern wahrend einer Massenvermehrung von Ips typographus in Norwegen Im vergangenen Jahrzehnt verursachte der Fichtenborkenkafer Ips typographus in den Waldern Norwegens ca. 5 Mio. m3 Schadholzanfall. Die Massenvermehrungen wurden durch umfangreiche Sturmschaden (1969) und ausergewohnliche Trockenheit (1975–1977) ausgelost. Am starksten betroffen waren Gebiete mit ausgedehnten Fichtenbestanden guter bis mittlerer Standortsklassen auf flachgrundigen Boden mit geringer Wasserspeicherkapazitat. Fur den Verlauf der Massenvermehrungen spielte die Anlage von Geschwisterbruten eine grose Rolle. Die Brutproduktion war verringert, um die Massenvermehrung zu begrenzen und einen Zusammenbruch durch Nahrungsmangel zu vermeiden. Fur die Absterberate der Fichten infolge Ips-Befall konnte kein Zusammenhang mit Rotfauleschaden festgestellt werden. Nach Kaferbefall abgestorbene Fichten bzw. solche, die sich wieder erholt hatten, konnten auch mit 15 weiteren Merkmalen fur Wuchsigkeit und Vitalitat nicht unterschieden werden. Es wird angenommen, das der Ruckgang der Kaferpopulation im wesentlichen durch zwei Faktoren bewirkt wurde: das kuhle und niederschlagsreiche Sommerwetter, welches die Flugaktivitat der Kafer einschrankte und die Widerstandskraft der Baume wieder herstellte sowie ein umfangreiches Bekampfungsprogramm, in dem Massenfang der Kafer mit synthetischen Lockstoffen eine wichtige Rolle spielte.