入世条件下林业可持续发展问题的探讨     

曹培忠  赵静静  周艳波 《林业研究》2004,15(2):161-166

世界贸易组织(简称WTO)，作为处理世界自由贸易机制的国际组织，允许为可持续发展和保护自由贸易和环境选择利用世界自然资源。中国作为世界贸易组织成员国，签定入世议定书，入世后中国在林业的可持续发展方面受到世界贸易组织的条约和原则的制约和挑战。中国的林业资源应当作为基础资源加以保护，政府的行政管理职能在世界贸易组织的原则下加以改革。因此，中国林业的可持续发展的目．标是优先处理环境保护和经济发展的关系。在入世条件下，按照世界惯例，中国林业资源可持续发展问题瞄准中国林业体制改革，以便适用中国天然林业战略，依靠科技进步依法保护中国环境，特别是在中国林业保护和处理环境和自然资源等关系方面。依据世界贸易组织的协议和规则，建立林业的生态化体系，尤其是GATT20条的规定，保护中国林业可持续发展，为中国林业创建国际环境。表1参21。  相似文献   

Development, manufacture and application of Beta-Cypermethrin aqueous capsule suspension   总被引：1，自引：0，他引：1  

LANGZi-jian SUYuan-ji WANGZhi-ying ChenLi-ping 《林业研究》2004,15(3):218-222

The optimal formula of Beta-Cypermethrin aqueous capsule suspension was screened out through the experiment,preparation and manufacture of basic formulas, which has no sedimentation, suspended drops of oil, peels and agglomerating and the diameter of capsule is in range of 10-30μm, conformed to the technical requirement. The aftereffect of the 3.3% Beta-Cypermethrin aqueous capsule suspension which was manufactured according to the optimal formula was up more than 25 days. The experiments on controlling the larvae of Dendrolinmus superans Butler and the adults of Xylotrechus rusticus L were carried out with different concentrations of this chemical. The death rate reached 80% when 250 times solution of the chemical was sprayed on stem to control the larvae of D. superans. For control of the adults of X. rusticus, 200, 400 and 600 times solution of the chemical were applied and their control effects (death rate) reached 85.23%, 74.21% and 66.59% respectively. Two kinds of solution (200 times and 300 times) of the chemical were used to control the larvae of D. superans in large area, and the control effect for both concentrations was over 90%.  相似文献   

A bioactive biflavonoid from Campnosperma panamense     

Weniger B  Vonthron-Sénécheau C  Arango GJ  Kaiser M  Brun R  Anton R 《Fitoterapia》2004,75(7-8):764-767

Lanaroflavone (1), a biflavonoid isolated from the methanol extract of the aerial part of Campnosperma panamense by bioguided fractionation, has been assessed for in vitro antiprotozoal activity. Lanaroflavone showed both antimalarial and leishmanicidal activities, but was inactive against Chagas disease vector, Trypanosoma cruzi.  相似文献   

Review of the <Emphasis Type="Italic">Eilema</Emphasis> group of lichen moths from South Korea,with description of one new species (Lepidoptera: Erebidae: Arctiinae: Lithosiini)     

Ulziijargal Bayarsaikhan  Young-Don Ju  Yang-Seop Bae 《林业研究》2016,27(2):407-417

This review details the Korean species of the Eilema group in the subfamily Arctiinae of Erebidae: 19 species in five genera (Manulea, Collita, Katha, Dolgoma, and Wittia), a new species (Collita hwacheonensis Bayarsaikhan & Bae, sp. nov.), and an unrecorded species [C. vetusta aegrota (Butler 1877)]. All species are diagnosed, and figures of the adults and genitalia and a key to species based on male genital structure of Eilema group in South Korea are included.  相似文献   

Effects of copper and cadmium on uptake and leakage of K(+) in birch (Betula pendula) roots     

Gussarsson M  Jensén P 《Tree physiology》1992,11(3):305-313

Uptake and leakage experiments were performed to study the effects of copper and cadmium on K(+) fluxes in birch (Betula pendula Roth) roots. Labeled rubidium ((86)Rb(+)) was used as a tracer for K(+). Plants were pretreated with Cu or Cd (0, 2, 5 or 25 microM) for 0-300 min and then transferred to radiolabeled nutrient solution (150 microM K(+)) with or without 2,4-dinitrophenol (DNP) to separate the effects of heavy metal on active and passive K(+) influxes. Passive K(+) influx was decreased by pretreatment with Cu but was only slightly affected by pretreatment with Cd. Pretreatment with 2 microM Cu increased active K(+) influx, whereas pretreatment with 25 microM Cu decreased active K(+) influx and intermediate Cu concentrations (5 microM) did not affect active K(+) influx. The pretreatment effects of Cu on active and passive K(+) influxes increased with increasing pretreatment time. During the first hour, pretreatment with Cd decreased active K(+) influx with increasing pretreatment time, whereafter recovery began. To measure K(+) efflux, birch plants were loaded with (86)Rb(+) for 7 days before being exposed to Cu or Cd (0, 1, 3, 5 or 10 microM) in unlabeled nutrient solutions for 24 h. Net efflux of K(+) was measured as (86)Rb(+)-activity in the nutrient solutions 24 h after a heavy metal had been introduced. Efflux of K(+) increased with increasing Cu or Cd concentration in the unlabeled nutrient solution.The data indicate that Cu and Cd affected K(+) influx differently and that recovery mechanism(s), which were induced shortly after heavy metal introduction, counteracted the heavy-metal induced inhibition of active K(+) influx. Efflux of K(+) from plant roots over a 24-h period indicated that Cu and Cd had similar effects on K(+) efflux. There was no evidence of a recovery mechanism counteracting the heavy-metal-induced inhibition of K(+) efflux.  相似文献   

Carbon, water and nutrient flux in Maya homegardens in the Yucatán peninsula of México     

T. J. Benjamin  P. I. Montañez  J. J. M. Jaménez  A. R. Gillespie 《Agroforestry Systems》2001,53(2):103-111

The Yucatán Peninsula of México has shallow soils and receives low amounts of precipitation, and has therefore low agricultural potential. Lacking large-scale irrigation from rivers and adequate rainfall, the indigenous Maya groups maintain agricultural productivity by adapting a variety of practices. Multistrata homegardens, one of their agricultural systems, have provided goods for trade, sale and personal consumption for many centuries. Nevertheless, an understanding of the controlling biological factors and interactions within these systems can lead to yield improvements. Photosynthetic rates, water use and litter production for a variety of species have been studied in these gardens to determine how Maya management impacts resource flow, productivity and diversity. When irrigated, diurnal photosynthetic rates nearly doubled for Manilkara zapota and water use increased two fold for M. zapota and Cordia dodecandra. Total litter production in traditional homegardens varied from 1,000 to 4,000 kg ha⁻¹ yr⁻¹ and ten arboreal species were found to contribute more than 33% of total litterfall biomass. Nutrient concentrations in the leaves of the predominant species were analyzed; Meliococcusbijugatus and Spondias purpurea were found to contribute the largest quantities of N, P and C. Our research indicates that species and structural diversity are critical to sustainability of homegardens, allowing efficient use and transfer of carbon, nutrients and water. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Public health effects of accidents in self-employed forestry work     

Emma Wilhelmson  Dianne Staal Wästerlund  Lage Burström  Per-Olof Bylund 《Small-Scale Forestry》2005,4(4):427-435

Little is known about the extent of work-related accidents occurring during the performance of forestry work by the non-industrial private forest owner or their assistant (hereafter called self-employed NIPF). The absence of an effective accident registration system largely excludes this group from accurate representation in official statistics. In this study, data from 1996 to 2001 were collected from hospital injury records managed by the Umeå Accident Analysis Group at the University Hospital in Umeå. During that period, it was found that 485 persons in the Umeå region were given medical attention due to injuries possibly acquired during self-employed forestry work. Questionnaires about the accidents were sent to each of the 485 injured persons and 80% were returned. Responses revealed that 225 of the respondents were injured during self-employed forestry work. Out of these, 81% performed fewer than 31 days of forestry work annually. Due to the injury, 29% had been on sick leave for some period of time and 42% had persistent symptoms. On average, each injury led to 13 days of sick leave and 24 hours of institutional care. Firewood production was shown to be a key factor behind the large number of accidents for self-employed NIPF. Further studies on the lack of knowledge about how the work should be done and conscious risk taking should be considered as an important link to the development of effective accident prevention strategies.  相似文献   

Tracking leaf area index and coefficient of light extinction over the harvesting cycle of black wattle     

Alexandre Behling  Carlos Roberto Sanquetta  Ana Paula Dalla Corte  Sylvio Péllico Netto  Aurélio Lourenço Rodrigues  Bráulio Otomar Caron  Augusto Arlindo Simon 《林业研究》2016,27(6):1211-1217

The amount of photosynthetic radiation intercepted by a crop is a function of the incident solar radiation on the plants, the leaf area index (L _AI), and the light extinction coefficient (k). We quantified L _AI and k in stands of black wattle (Acacia mearnsii De Wild.) over a 7-year growth cycle at two locations in the state of Rio Grande do Sul, Brazil. Our study was conducted in commercial stands in agroecological regions with high densities of black wattle plantations. L _AI was calculated as the ratio between the leaf area of a tree and its planting space, and k was derived from Beer’s law. L _AI depends on the planting site and stand age. Between the two sites, the L _AI was similar over time, the amount of variation differed. Values of k depended only on stand age, with the highest average observed for stands up to 5 years old. The trend of k during the plantation cycle was inversely proportional to L _AI and was correlated with L _AI, leaf area, leaf dry mass, canopy volume, height, branches dry mass, total dry mass, and crown diameter.  相似文献   

Improvement of the tissue culture technique for <Emphasis Type="Italic">Melaleuca alternifolia</Emphasis>     

Bihua Chen  Jianmin Li  Juan Zhang  Huihua Fan  Lijun Wu  Qianzhen Li 《林业研究》2016,27(6):1265-1269

Tea tree oil is extracted from the leaves and twigs of Melaleuca alternifolia (Maiden & Betche) Cheel, and it is widely used in medicines, food preservatives, cosmetics and health care products. Traditional propagation of M. alternifolia from seeds does not necessarily transfer the desired characteristics from their mother trees, the seedlings are not uniform, and the multiplication rate from cuttings is relatively low. For these reasons, it is necessary to develop tissue culture techniques for this species. This study showed that an efficient explant initiation medium for M. alternifolia was MS 1/2 + BA 0.6 mg L^?1 + NAA 0.1 mg L^?1 + sucrose 30 g L^?1, which yielded a 75.9 % initiation rate. An efficient multiplication medium was MS + BA 0.3 mg L^?1 + NAA 0.15 mg L^?1 + sucrose 30 g L^?1, which yielded a 4.3 multiplication rate and 3.2 cm shoot length. The rooting medium was MS 1/2 + IBA 0.1–0.25 mg L^?1 + sucrose 15 g L^?1, which yielded a 100 % rooting rate, 2.94–3.32 roots per individual and 1.36–1.44 cm root length. Local red-core soil was suitable as a transplant medium, and yielded 98 % survival. This study improved the tissue culture technique for mass-propagation of M. alternifolia, enabling the production of high quality plants for market.  相似文献   

Temporal and spatial dynamics of an old-growth beech forest in western Japan     

Uyanga Ariya  Ken-Ya Hamano  Takushi Makimoto  Shu Kinoshita  Yasuaki Akaji  Yuko Miyazaki  Muneto Hirobe  Keiji Sakamoto 《Journal of Forest Research》2016,21(2):73-83

Dendrochronological approaches enable us to understand forest stand dynamics by estimation of disturbance history and age structure. The present study was conducted in an old-growth beech forest in a forest reserve in western Japan. Increment cores were taken for tree ring analysis from all canopy trees in a 50 m × 130 m study plot. Radial growth release criteria were developed to identify significant growth releases in each tree ring series and to characterize the disturbance history of the study site. The age structure of the forest was indicative of continuous establishment by Fagus crenata and simultaneous establishment by Magnolia obovata. A variety of low-intensity disturbances were identified in each decade, especially after the 1900s, but the occurrence of high-intensity catastrophic disturbance was rare, and likely played an important role in maintaining species diversity in the existing forest canopy. The results also suggest that F. crenata regenerates gradually before and after both large- and small-scale disturbances, whereas M. obovata and Betula grossa regenerate only after large-scale catastrophic disturbances.  相似文献