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.

The onset of photosynthetic acclimation to elevated CO2 partial pressure in field‐grown Pinus radiata D. Don. after 4 years

Abstract: The effects of CO 2 enrichment on photosynthesis and ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) were studied in current year and 1-year-old needles of the same branch of field-grown Pinus radiata D. Don trees. All measurements were made in the fourth year of growth in large, open-top chambers continuously maintained at ambient (36 Pa) or elevated (65 Pa) CO 2 partial pressures. Photosynthetic rates of the 1-year-old needles made at the growth CO 2 partial pressure averaged 10.5± 0-5 μmol m -2 s -1 in the 36 Pa grown trees and 11.8± 0-4 pmol m -2 s -1 in the 65 Pa grown trees, and were not significantly different from each other. The photosynthetic capacity of 1-year-old needles was reduced by 25% from 23-0 ± 1-8 pmol m -2 s -1 in the 36 Pa CO 2 grown trees to 17.3 ± 0.7 μmol m -2 s -1 in the 65 Pa grown trees. Growth in elevated CO 2 also resulted in a 25% reduction in V cmax (maximum carboxylation rate), a 23% reduction in J max (RuBP regeneration capacity mediated by maximum electron transport rate) and a 30% reduction in Rubisco activity and content. Total non-structural carbohydrates (TNC) as a fraction of total dry mass increased from 12.8 ± 0-4% in 1-year-old needles from the 36 Pa grown trees to 14.2±0.7% in 1-year-old needles from the 65 Pa grown trees and leaf nitrogen content decreased from 1-30 ± 0-02 to 1.09 ± 0.10 g m -2 . The current-year needles were not of sufficient size for gas exchange measurements, but none of the biochemical parameters measured (Rubisco, leaf chlorophyll, TNC and N), were effected by growth in elevated CO 2 . These results demonstrate that photosynthetic acclimation, which was not found in the first 2 years of this experiment, can develop over time in field-grown trees and may be regulated by source-sink balance, sugar feedback mechanisms and nitrogen allocation.

Sphingomyelinase Induces Aggregation and Fusion of Small Very Low-Density Lipoprotein and Intermediate-Density Lipoprotein Particles and Increases Their Retention to Human Arterial Proteoglycans

Abstract: Objectives— Infiltration of low-density lipoprotein (LDL) into subendothelial space is an early step in atherosclerosis. In addition to LDL particles, small very low–density lipoprotein (sVLDL) and intermediate-density lipoprotein (IDL) particles are also able to enter the arterial intima and be retained within the subendothelial extracellular matrix. Here we compared how proteolysis with α-chymotrypsin and phospholipid hydrolysis with phospholipase A 2 or sphingomyelinase (SMase) of sVLDL, IDL, and LDL particles can influence their aggregation, fusion, and binding to human arterial proteoglycans in vitro. Methods and Results— In each of the 3 lipoprotein classes, the particles became only slightly aggregated with α-chymotrypsin or phospholipase A 2 . However, the particles strongly aggregated when treated with SMase. The aggregated/fused particles were found to bind to proteoglycans in proteoglycan affinity chromatography more tightly than the native-sized counterparts. In addition, in a microtiter well assay, the binding of SMase-treated lipoproteins was enhanced: the amounts of proteoglycan-bound SMase-treated LDL, IDL, and sVLDL were 4-, 5-, and 20-fold higher, respectively, than the amounts of proteoglycan-bound native lipoproteins. Conclusion— These results imply a specific role for SMase as an sVLDL- and IDL-modifying enzyme and also suggest a novel mechanism of lipid accumulation in atherogenesis, namely enhanced retention of atherogenic triglyceride-rich lipoprotein particles in intimal areas expressing extracellular SMase activity.

Differential success in northwards range expansion between ecotypes of the marble gallwasp Andricus kollari: a tale of two lifecycles.

Abstract: The Marble gallwasp Andricus kollari has a native range divided into two geographically separated lifecycles. In Eastern Europe and Turkey, the lifecycle involves a sexual generation on Turkey oak, Quercus cerris, while in Iberia and North Africa the sexual generation host is cork oak, Q. suber. Over the last 500 years, A. kollari has expanded its range into northern Europe, following human planting of Q. cerris from Italy and the Balkans. We ask: (i) what is the genetic relationship between eastern and western distributions of Andricus kollari? Can we determine which lifecycle is ancestral, and how long ago they diverged? (ii) To what extent have eastern and western native ranges contributed to northwards range expansion? (iii) Is there any evidence for hybridization between the two life cycle types? We present analyses of allozyme data for 13 polymorphic loci and of sequence variation for a 433 bp fragment of the mitochondrial cytochrome b gene. These show: (i) that four haplotype lineages (one in Spain, two in Hungary/Italy and one in Turkey) diverged more or less simultaneously between 1 and 2 million years ago, suggesting the existence of at least four refuges through recent ice age cycles. Our data cannot resolve which lifecycle type is ancestral. (ii) Populations north of putative refuges are divided into two sets. Populations in south-west France are allied to Spain, while all remaining populations in northern Europe have been colonized from Italy and the Balkans. (iii) The transition from one race to another in south-west France is marked by abrupt transitions in the frequency of refuge-specific private alleles and corresponds closely to the northern limit of the distribution of cork oak. Although hybrids were detected in north-west France, none were detected where the two lifecycles meet in south-western France. The biology of oak gallwasps predicts that any hybrid zone will be narrow, and limited to regions where Q. cerris and Q. suber meet. Our data suggest that eastern and western A. kollari are effectively separate species.

Nutrient return in litter and rainfall under some exotic conifer stands in New Zealand

Abstract: Summary Because changes in the nutrient content of the soil after afforestation may result in slower growth of succeeding tree crops, a study is being made of the changes taking place in pumice soils under exotic conifers in New Zealand. As litter plays a large part in determining the future nutrient status of the soil, monthly litter-fall collections have been made for several years under radiata pine, Corsican pine, Douglas fir, and European larch. The nutrient compositions of the litters are similar to those reported from other countries but the total annual weights of litter fall are greater in New Zealand. The air-dry weight of litter falling under both radiata and Corsican pines exceeded 8000 lb/ac in one year and averaged more than 5000 Ib/ac/yr. The rate of needle fall under Douglas fir does not vary greatly with season but most Corsican-pine needles fall in the autumn. Under radiata pine there is also a peak needle fall in the autumn but considerable quantities of needles fall throughout the year...