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.

Use of Indicator Species to Assess Forest Continuity: a Critique

Abstract: Conservation biologists often must apply novel approaches to address critical issues before they have been thoroughly validated by scientific studies. One technique of particular interest is the use of indicator species as a shortcut to assess ecological conditions or species assemblages too difficult to measure directly (e.g., Landres et al. 1988; McGeoch 1998; Caro & O'Doherty 1999). It is necessary to acknowledge the inherent complexity of natural ecosystems and the need for reliable indicators or surrogate measures. Whereas the spatial aspects of forest fragmentation have received much attention, less focus has been put on the temporal dimension, on what has been called forest continuity, or the uninterrupted, site-specific pres.ence in time of a forest stand or components thereof (Nilsson et al. 1995). Concern has risen that many forestdwelling organisms are strongly dependent on continuously present forest stands or structural components, partly because these organisms are poor dispersers and therefore unable to recolonize secondary stands that emerge after logging (Duffy & Meier 1992). Thus, a break in continuity is the temporal counterpart of fragmentation in space. If assemblages of forest organisms are not replaceable within reasonable time, it has been suggested that forest continuity should be the prime criterion for the selection of forest reserves (Nilsson et al. 1995). During the last decade, it has been proposed that indicator species be used to identify forest stands with long-term continuity of structural components, especially old-growth or old-growth-resembling stands (e.g., Tibell 1992; 0kland 1996; Selva 1996; Bredesen et al. 1997; Lindblad 1998). Recently, the indicator-species concept has been applied in forest survey programs,

Seasonal and geographical variation of terpenes, resin acids and total phenolics in nursery grown seedlings of Scots pine (Pinus sylvestris L.)

Abstract: summary Variations of terpene, resin acid and total phenolic concentrations in young seedlings of Scots pine (Pinus sylvestris L.) from nine different seed origins growing in three locations of different latitudes, in Finland and Estonia, were investigated in autumn 1991 and spring 1992. Seasonal variation was remarkable in monoterpene, resin acid and total phenolic concentrations. In spring there was more 3-carene, α-pinent. β-pinene + sabinene and total monoterpenes in pine shoots, and less myrcene and tricyclene compared to autumn. Concentrations of some individual resin acids, levopimaric and dehydroubietic acids, were higher in autumn. The total phenolic concentration was higher in spring. In the most northern location, the concentrations of total monoterpenes and total phenolics were lowest. The total resin acid concentration was highest in the middle location, and individual resin acids, palustric and neoabtetic acids, were more common in the most northern location. Seed origin had no significant effects either to the resin acid or total phenolic concentrations. There were almost equal concentrations of total phenolics and resin acids in northern and southern origins. Instead some individual monoterpenes. limonene, tricyclene, camphene, β-pinene + sabinene and bornylacetate, were more common in northern seed origins. The results suggest that the origin of the seed material is not so important in affecting the concentrations of secondary compounds as are the environmental factors.

Irradiance and Spectral Quality Affect Asian Tropical Rain Forest Tree Seedling Development

Abstract: Plant developmental responses to shade are the combination of reductions in photosynthetic photon flux density (PPFD) and changes in spectral quality (reductions in the quantum ratio of red to far-red band widths, R:FR). We studied the seedling devel- opment of six Asian tropical rain forest trees, Dryobalanops aromatica, Endospermum malaccense, Hopea wightiana, Parkia javanica, Shorea singkawang, and Sindora echi- nocalyx under varying PPFD and R:FR. Seedlings were grown in replicated shadehouse treatments: (1) 40% solar PPFD and 1.25 R:FR; (2) 11% PPFD and 1.25 R:FR; (3) 11% PPFD and 0.24 R:FR; (4) 3% PPFD and 1.25 R:FR; and (5) 3% PPFD and 0.23 R:FR. Species differed in the influence of light variables on seedling (1) total height; (2) internode distance; (3) branch to trunk internodes; (4) stem length/mass; (5) leaf area/stem length; (6) percent allocation to leaf, stem and root mass; (7) specific leaf mass; (8) mean leaf area; (9) leaf thickness; (10) petiole length; and (11) stomatal density. The simple factorial design of treatments 2-5 allowed a two-way ANOVA and the calculation of coefficients of determination of the treatment effects. The characters in most taxa were primarily in- fluenced by light intensity, but spectral quality also influenced characters in many cases. The taxa that responded most strongly to the light treatments were the most shade-intolerant: E. malaccense and P. javanica; the former species responded strongly to R:FR, particularly in stem mass allocation and leaf area/stem length. The four taxa with moderate-to-extreme shade tolerance varied considerably in responses of individual characters to R:FR and PPFD. The patterns of morphological responses to reduced PPFD and R:FR help explain how the shade tolerances of the seedlings of rain forest trees vary in a continuous manner. Rec- ommendations concerning seedling shade tolerance for sylviculture or nursery practice may need revision if they were based on shade trials using spectrally neutral shade fabrics or slat houses. Future research on the effects of shading on tree seedling development and ecology must consider the potential influence of changes in spectral quality under canopy shade.

Effects of thinning on growth of six tree species in north-temperate forests of Lithuania

Abstract: This paper summarises the results from 35 years-observed thinning experiments on 256 permanent sample plots in 10–60 year-old stands of ash, aspen, birch, oak, pine and spruce in Lithuania. Thinning enhanced crown projection area increment of residual trees. The largest effect was observed in stands of aspen and birch (growth increase by 200%), followed by ash and oak (over 100%), and spruce and pine (about 80%). Thinning also promoted dbh increment, especially in younger stands, and the increase of dbh increment was positively correlated with the thinning intensity. The strongest reaction was exhibited by oak and aspen, while ash, birch and conifers reacted to a lower extent. Low and moderate intensities of thinning stimulated volume production in younger stands while the opposite was observed in older stands with increasing removals. Spruce stands exhibited relatively strongest increase of volume increment and pine, –the weakest, while the effect on deciduous species was intermediate. The results demonstrate that significant increase in volume increment is achievable with thinning of only young forest stands, e.g. 10–20 year-old pine, birch and ash, or 10–30 year-old oak, aspen and spruce.