Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FORESTRY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88Linked to original sources
PubMed2004

[Ecological technique of cultivating Coptis chinensis in woods and co-cultivating it with maize].

OBJECTIVE: To establish ecologically new modes of cultivating Coptis chinensis in woods and co-cultivating it with maize. METHODS: Based on the experience obtained from plot comparative test and production test, we used application-oriented research methods, and established new Coptis chinensis cultivation techniques that protect the natural environment. RESULTS: Coptis chinensis was harvested 6 years after cultivation. Yield of Coptis chinensis cultivated in forest (69.5 kg per 0.067 hm2) was higher with 3.7% than that in controls which cultivated under shed (67 kg). Yield of Coptis chinensis co-cultivated together with maize (168.4 kg per 0.067 hm2) was lower with 15.8% than that in controls which cultivated under shed (200 kg). CONCLUSION: The new cultivation modes of Coptis chinensis is an ecologically new technique that assures the good growth of medicinal plants, cereals, forest and animal husbandry.

Agriculture↗
PubMed2004

[Quality assessment for Coptis chinensis planted with ecological techniques].

OBJECTIVE: To evaluate the quality difference between Coptis chinensis planted with ecological techniques and shelf planted Coptis chinensis. METHODS: Ultraviolet-visible spectrophotometry, alcohol extract mensuration, moisture mensuration, and ash mensuration were used to determine the contents of total alkaloids, alcohol extract, water, and total ash of Coptis chinensis, which were planted in shelf, Rhus chinensis wood, M mulbery wood, corn wood, Magnolia officinalis wood, fruiter wood, shading net, and firry wood, respectively. RESULTS: The contents of total alkaloids and alcohol extract of Coptis chinensis Table planted with ecological techniques were higher than those of Coptis chinensis planted in shelf. The contents of water and total ash were less than 12% and 5%, respectively, which met the provisions of the pharmacopoeia. CONCLUSION: The quality of Coptis chinensis planted with ecological techniques is similar to that of Coptis chinensis planted in shelf. These ecological techniques for Coptis chinensis have become mature and practical.

Agriculture↗
PubMed2004

[Mechanism analysis of optimized model of conversion from farmland to forestland in the hill-gully sub-region of Loess Plateau].

Conversion from Farmland to Forestland Program (CFF) is one of the six great ecological forest programs in China. This study covered the CFF model area of the hilly-gully sub-region of loess plateau, and introduced system dynamics and other latest theories and methodologies. Based on the analysis of five modules including that of the site observation of field stations and extensive investigations, and over 10000 original data obtained in the fields of natural science, social science and economics, the operational mechanism of the optimized model was studied. The optimized operational models integrated maximized ecological, economic and social benefits, while sustainability concepts were proposed for typical CFF sites: The Pinus tabulaeformis + Platycladus orientalis + Zanthoxylum spp. + Robinia pseudoacacia model at the eroded flat ridges of the middle reaches of the Yellow River. The result showed that the ecological, economic and social benefits of the optimized model reflected by main indexes were the best or better, and in the other models, either individual one was the best or others were not. From the viewpoint of comprehensive comparison of three great benefits, the optimized model was most excellent, and had eminent difference comparing to other ones through F test. The relationship between ecological and social benefit was eminent positive correlative. Social benefit was the same with economical one at some degrees. The relationship between ecological and economical benefit was more complicated. On the whole, they were positive correlative, but the economical benefit was not the greatest when the ecological one was the greatest. In general, from the viewpoint of largest comprehensive benefit, the three great benefits were not all the best, indicating that the combination of the modules must be reasonable. In order to achieve the ultimate goal of CFF, we must choose the optimized combination of ecological, economical and social benefits, and can't only pursue any one maximum of three great benefits.

China↗
PubMed2005

Economic assessment of the negative impacts of ozone on crop yields and forest production. A case study of the estate Ostads Säteri in southwestern Sweden.

Ground level ozone concentrations, in combination with the prevailing climate, at the estate Ostads Säteri in southwestern Sweden were estimated to reduce the yield of wheat and potato ranging between 5% and 10%. Occasionally, in years with the highest ozone concentrations and/or climatic conditions favoring high rates of ozone uptake to the leaves, yield loss levels above 10% may occur. Based on simple extrapolation, these ozone-induced reductions of crop yields at Ostads Säteri represent a potential total annual yield loss in Sweden in the range of 24.5 million Euro for wheat and 7.3 million Euro for potato, respectively. A simulation of forest growth at Ostad Säteri predicted that prevailing mean ozone exposure during 1993-2003 had the potential to reduce forest growth by 2.2% and the economic return of forest production by 2.6%. Using this value for extrapolation to the national level, the potential annual economic loss for Sweden due to negative impacts of ozone on forest production would be in the range of 56 million Euro (2004 prices).

Agriculture↗
PubMedDate not supplied

[Successions in the forest-steppe under climate changes: a modelling approach].

The paper represents an attempt to apply the general principles of modelling vegetation dynamics under climate changes to a study of the long-term vegetation dynamics in the forest-steppe zone of the European territory of Russia, with a purpose to forecast under special climatic scenarios. An original technique is used to construct a Markov chain as a model of vegetation succession. The technique emanated from gebotanic knowledge generalized as a scheme of successional transitions with estimates of the average duration for certain stages of succession. Whenever the knowledge related the stage duration to certain (climate-sensitive) factors of the environment, the fundamental potentiality arises to model the temporal course of succession as a function of a given scenario for how the key factors change. In the formal terms, the model represents a random chain of the Markov kind with a finite number of states and discrete time of transitions by the given scheme. Relative square distributions of succession stages under concern at any time moment (within an adopted scenario) appear as the model outcome (forecasts), as well as estimates of the attainment time for certain states of the vegetation in the territory under study. A method is proposed to describe dynamics of the phytomass production and stores (and the corresponding model trajectories are obtained) for a given scenario.

Adaptation, Physiological↗
PubMed2004

Evaluation of some competition indices for the construction of Lebanon cedar (Cedrus libani A. Rich.) stand models.

The purpose of this research is to test the precision of some published competition indices of Lebanon cedar (Cedrus libani A. Rich.) for the estimation of future periodic diameter increment of individual trees. Twenty- nine published competition indices were tested, using fifteen separate sets of data and their pooled values, collected from various stand age and site quality classes Lebanon cedar at Antalya. Temporary sample plots were taken in Elmali-Qamkuyusu (9 sample plots) and Finike-Pinarcik (6 sample plots) in 2001. Every plot was stem mapped (x and y coordinate system), diameter (dbh), total height, crown length, crown diameter and 10-year radial increment were recorded for trees greater than 4 cm in dbh. Then, in order to evaluate these competition indices for the prediction of the periodic diameter increment of the individual trees. Three linear models have been constructed for each competition index. It was found that the competition indices (Daniels et al., 1986; Biging and Dobbertin, 1995; Pukkala and Kolström, 1987; Hegyi, 1974) with larger influence-zone areas produce better results.

Cedrus↗
PubMedDate not supplied

[The recent trend of the biodiversity dynamic of biotic communities in forest-steppe oak forests].

Comparative studies of the structure and diversity of model biotic communities (grass cover, soil macrofauna, xylotrophic fungi and xylophilous coleopterans) were carried out in oak forests of the core and buffer zones of the Voronezh biosphere reserve. The functional structure of the communities in the buffer zone had clearly expressed nemorose features characteristic of the broad-leaved zonal forests, while that in the core zone demonstrated more xerophilous patterns with a wide participation of meadow-steppe elements. The restricted anthropogenic activity in the buffer zone enhances the mesophytization of the oak forest habitats. Complete elimination of anthropogenic pressure in the core zone for two last decades results in the formation of a peculiar, dynamic pattern of forest ecosystems, which corresponds to the zonal climatic conditions.

Biodiversity↗
PubMed2005

Conservation and development in Amazonian extractive reserves: the case of Alto Juruá.

Extractive reserves constitute an innovative approach to match conservation and development objectives, which were originally envisaged as part of a land struggle by forest dwellers in Brazil. In spite of the idea's popularity and the attempts to apply the concept to different tropical regions, there has been little analysis of the combined conservation and development performance of extractive reserve programs. We present a detailed analysis of deforestation and demographic and socioeconomic changes in Alto Juruá, the first extractive reserve created in Brazil in 1990. Forest cover has remained fairly stable. Population has declined slightly, with some internal displacements. The cash economy base has shifted from the original rubber production to a diversified portfolio of agriculture and livestock, and there has been a dramatic rise in nonagrarian income. We conclude that the Reserve represents a very dynamic setting with positive conservation and development outcomes during its first decade.

Agriculture↗
PubMed2005

The ecological and economic potential of carbon sequestration in forests: examples from South America.

Costs of reforestation projects determine their competitiveness with alternative measures to mitigate rising atmospheric CO2 concentrations. We quantify carbon sequestration in above-ground biomass and soils of plantation forests and secondary forests in two countries in South America-Ecuador and Argentina-and calculate costs of temporary carbon sequestration. Costs per temporary certified emission reduction unit vary between 0.1 and 2.7 USD Mg(-1) CO2 and mainly depend on opportunity costs, site suitability, discount rates, and certification costs. In Ecuador, secondary forests are a feasible and cost-efficient alternative, whereas in Argentina reforestation on highly suitable land is relatively cheap. Our results can be used to design cost-effective sink projects and to negotiate fair carbon prices for landowners.

Argentina↗
PubMed2005

Government plans and farmers intentions: a study on forest land use planning in Vietnam.

In 1998, the Vietnamese National Assembly approved a Five Million Hectare Reforestation Program, (5MHRP) 1998-2010. It would increase forest cover by some 45%, use barren hills, produce wood, and generate socioeconomic development. It would, however, also put demands on Vietnamese planning. Experiences from a former development project and two case studies from a commune and village are used as a basis for analyzing the planning system. The study describes the objectives and strategies of government and farmers in one commune and one village and analyzes how planning data influence scenarios on future development. Official planning data do not reflect reality but are derived through negotiations. In the commune and village studied, it would be difficult for the 5MHRP to materialize, as most of the forest land, officially not yet used, is actually used for food production. The approach and method used by the study offers alternatives to current planning practices.

Agriculture↗
PubMed2005

Long term effects of thinning on soil and forest floor in a sessile oak (Quercus petrea (Matlusch) Lieb.) forest in Turkey.

The effects of thinning on mineral soil and forest floor for three different thinning intensities (control, moderate and heavy) were studied in a sessile oak forest 8 years after treatment. To examine responses to thinning, mass, organic matter and total nitrogen content in forest floor, bulk density and fine soil weight, total nitrogen, organic carbon concentrations and pH in upper mineral soil horizons were measured, and the results compared to control plot. The thinned plots have shown higher total nitrogen concentration and organic carbon in soil. Total mass, weight of layers of forest floor have shown significant patterns with thinning intensity. The present results indicate that various intensities of thinning for a sessile oak stand had major influence on soil and forest floor in eight years following treatment.

Biomass↗
PubMed2005

[Neural network grade program of natural forest protection].

In this paper, the implement steps of natural forest protection program grading (NFPPG) with neural network (NN) were summarized, and the concepts of program illustration, patch sign unification and regress, and inclining factor were set forth. Employing Arc/Info GIS, the tree species diversity and rarity, disturbance degree, protection of channel system, and classification management in Moershan National Forest Park were described, and, used as the input factors of NN, the relationships between NFPPG and above factors were analyzed. Through artificially determining training samples, the NFFPG of Moershan National Forest Park was built. Tested with all patches in the park, the generalization of NFFPG was satisfied. NFPPG took both the classification management and the protection of forest community types into account, as well as the ecological environments. The excitation function of NFPPG was not seriously saturated, indicating the leading effect of inclining factor on the network optimization.

Conservation of Natural Resources↗
PubMed2005

Soybean production and conversion of tropical forest in the Brazilian Amazon: the case of Vilhena, Rondônia.

The recent rise in Brazilian soybean production has generated concern among the environmental community and some authors that natural tropical environments of the Amazon Basin are being converted to soybean fields. Proponents of soybean production counter that soybeans represent a viable agricultural commodity for the region; environmental concern is unwarranted, because new soybean fields are replacing already deforested or otherwise transformed lands. Both arguments have been made without comprehensive study and measure of land-use/land-cover (LULC) in areas undergoing expansion of soybean production. This case study, conducted in the municipality of Vilhena, Rondônia, Brazil, in the southwestern Amazon Basin, uses remote sensing to evaluate the LULC accompanying this municipality's large growth in soybean production from 1996 to 2001. Forests are being converted for soybean production, but most of the production increase appears attributable to slight expansion of already existing fields, conversion of already deforested land, and higher yields.

Brazil↗
PubMed2005

Eco-environment contribution of agroforestry to agriculture development in the plain area of China--Huai' an Prefecture, Jiangsu Province as the case study area.

For improving the environmental quality and ensuring supply of wood and non-timber forest products, many forests have been planted in plain areas of China. Scientists have studied their benefits, almost all of the approaches were based on fixed-point data, and few was considered on the non-efficient factors and temporal scale effects. This paper studies the positive and negative benefits at a large temporal scale, and the effects of plain afforestation on stockbreeding and rural economy. The benefits of plain afforestation, correlation coefficiency of agroforestry and production factors are analyzed via stochastic frontier modeling in Huanghuaihai Plain Area of China; elastic coefficient of agroforestry, husbandry, farming, and total output of agricultural sector are calculated through adopting partial differential equation. Some conclusions can be drawn that, plain forests have an important effect on the development of plain agriculture. But shelterbelts and small-scale forests have different effect on the development of agricultural economy. Shelterbelts have negative effect on the industries, but small-scale forest has positive effect. On the whole, contribution of forest resource to value of animal husbandry and gross production value of agriculture is positive, and to the value of farming is negative.

Agriculture↗
PubMed2005

[Forest landscape restoration and its affecting factors in burned area of northern Great Xing'an Mountains--taking forest coverage as an example].

Forest landscape restoration has been an attractive issue since the catastrophic fire took place on the northern slope of Great Xing'an Mountains in 1987. Based on the China forest inventory data and employing Kendall Bivariate and Distances Correlation Analyses, an investigation was made to search for what changes of the forest coverage pattern being happened in this area during the past 13 years after fire, and how the fire severity, foster type and terrain factors influenced the restoration of forest coverage. The results showed that the forest coverage in 2000 changed a lot, in comparing with that in 1987 before fire. The percentage of non-stocked land area and coverage grade declined markedly, with lower coverage grade increased. Among all test factors, fire severity which was inversely correlated with forest coverage grade was the key one. Though the regeneration measures didn't markedly affect forest coverage restoration within a short period, they might shorten the cycle of forest succession and promote the productivity of coniferous forest in the future. Among three terrain factors, slope was the strongest one affecting forest coverage, followed by position and aspect.

Biodiversity↗