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Indigenous Tree Species (indigenous + tree_species)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

Perennialism and Poverty Reduction

DEVELOPMENT POLICY REVIEW, Issue 1 2004
Nigel D. Poole
This article, which is both conceptual and a synthesis of the literature, considers the research component of poverty alleviation strategies for people whose livelihoods depend significantly on tree and forest resources. Two policy approaches are contrasted: enhancing the utilisation of indigenous tree species within the household and the local economy, and integrating tree and forest-dependent peoples into the wider economy by promoting the commercialisation of conventional tree crop production. It is argued that the discussion is relevant for other poor peoples who depend on perennial production systems, and that the conclusions contribute to the wider debate about remoteness, market access, decentralisation and targeting in policy formulation, and globalisation. [source]

Soil and atmospheric water deficits and the distribution of New Zealand's indigenous tree species

FUNCTIONAL ECOLOGY, Issue 2 2001
Leathwick J. R.
Summary 1.,An extensive data set describing the composition of New Zealand's remaining indigenous forests was used to estimate the degree of correlation between measures of both soil and atmospheric water deficit and the distribution of common tree species. 2.,For most species, regression models incorporating measures of air saturation deficit in early autumn, as well as an annual integral of root zone water deficit, provided the best explanation of spatial distribution. This accords strongly with the mechanistic effects of air saturation deficits on transpiration from trees, and the hydraulic risks experienced by trees under high evaporative demand. 3.,Adjustment of root zone water deficits to account for reductions in rainfall in dry years substantially improved model predictions. This suggests that extreme climatic events, such as the El Niño phase of the Southern Oscillation, are likely to have strongly influenced the historic composition of forests in New Zealand's drier eastern lowlands. [source]

Dendroclimatic signals in long tree-ring chronologies from the Himalayas of Nepal

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2003
Edward R. Cook
Abstract We describe the development of a tree-ring chronology network in Nepal that is suitable for reconstructing temperature-related climate forcing over the past few hundred years. The network is composed of 32 tree-ring chronologies and is represented by five indigenous tree species. An empirical orthogonal function analysis of the chronologies over the common interval 1796,92 indicates the existence of coherent large-scale signals among the tree-ring chronologies that are hypothesized to reflect, in part, broad-scale climate forcing related to temperatures. A long monthly temperature record for Kathmandu is developed and used to test this hypothesis. In so doing, significant monthly and seasonal temperature responses are identified that provide guidance for the formal reconstruction of two temperature seasons: February,June (1546,91) and October,February (1605,91). Each reconstruction indicates the occurrence of unusually cold temperatures in 1815,22, which coincides with the eruption of Tambora in Indonesia. A novel method is also used to add probable missing multi-centennial temperature variance to each reconstruction. The resulting ,adjusted' reconstructions strongly reflect patterns of temperature variability associated with Little Ice Age cooling and warming into the 20th century, with the October,February season exhibiting the strongest increase in temperature over the past ,400 years. Only the October,February season shows any evidence for late- 20th century warming, whereas February,June temperatures have actually cooled since 1960 (as with the observational series). Copyright © 2003 Royal Meteorological Society [source]

An Analysis of Forest Restoration 120 Years after Reforestation on Badlands in the Southwestern Alps

RESTORATION ECOLOGY, Issue 1 2002
Daniel R. Vallauri
Abstract We report the results of descriptive and functional analyses of a representative forest and watershed in the southwestern Alps, where the Forest Service has attempted reforestation of badlands for erosion control since 1860, relying on the non-native Pinus nigra ssp. nigra (Austrian black pine). One hundred twenty years after the first tree plantings, the plant communities are still early seral assemblages for the most part, with Austrian black pine occurring alone in the canopy. In contrast, most of the marly soils have physically recovered part of their total depth, with layers of fragmented and altered material equal to 50 cm, but their structure and chemical fertility is still poor. Autogenic soil restoration is proceeding however, largely engineered by earthworms (up to 49 individuals and 27 g/m2). Two dominant species are presumed keystone: Lumbricus terrestris and Octolasion cyaneum (Lumbricidae). The reestablishment of indigenous tree species is apparently not inhibited by site fertility or lack of nearby seed pools. We hypothesize that excessive stand density is responsible for the poor regeneration because it discourages the birds and rodents that control seed dissemination. Mortality of pines due to infestation by Viscum album subsp. austriacum (mistletoe) is creating large openings and should be specially managed. One hundred twenty years after the first plantings, the nineteenth-century vision that restoration of badlands was ecologically feasible is validated, as is the strategy to establish pioneer tree species. Here Austrian black pine acts as a nurse stand and enables the return of indigenous broad-leaved trees and a wide array of herbaceous species as well. However, our results clearly indicate that appropriate silvicultural tactics should now consist of tree thinning to promote the true restoration of native biodiversity and ecosystem functions. [source]