皖南枫香造林技术要点

枫香是我国的乡土树种,具有生长快,适应性广,耐干旱瘠薄土壤,天然更新容易等特点.枫香在次生林中常为优势树种,人工造林可与松、杉、毛竹等树种混交.为大力发展枫香造林,丰富我国造林树种,改善林地生态环境,调整林树种结构,促进祁门林业可持续发展,1996年～2003年,祁门县林业局与南京林业大学联合开展<枫香多目标育种及栽培技术研究>,经过多年的共同努力,完成了枫香优树选择、苗期子代测定及子代林营建、常规造林等工作,尤其在营造大面积工业原料林时,苗木选用、整地规格以及造林密度均严格要求,取得了很好经济、社会和生态效益.     

皖南枫香造林技术要点

枫香是我国的乡土树种,具有生长快,适应性广,耐干旱瘠薄土壤,天然更新容易等特点。枫香在次生林中常为优势树种,人工造林可与松、杉、毛竹等树种混交。为大力发展枫香造林,丰富我国造林树种,改善林地生态环境,调整林树种结构,促进祁     

枫香播种育苗

枫香,速生树种,耐干旱瘠薄,天然更新容易,萌芽能力强,在次生林中常为优势树种。人工造林可与马尾松等混交,栽植容易,成活率高,是荒坡造林绿化的先锋树种,也是香茹、木耳栽培     

枫香造林技术

枫香是我国的乡土树种,具有生长快、适应性广、耐干旱瘠薄土壤、天然更新容易等特点.枫香在次生林中常为优势树种,人工造林可与松、杉、毛竹等树种混交.祁门县查湾采育场1997年3月营造的30亩枫香林(密度196株每亩),3年生平均高2.9米,平均胸径2.6厘米,最大树高为4.5米,最大胸径4.6厘米,平均冠幅2.5米×4.2米,林分基本郁闭.根据枫香的生物学特性,结合近年来祁门县营造枫香林的经验,对枫香的造林技术作一简介.     

枫香人工造林技术与效果

枫香是更新造林的先锋树种与优势树种。研究总结了千岛湖区枫香育苗、造林的各个环节技术措施 ,提出了枫香苗木的质量标准 ,认为枫香及其混交林在千岛湖区具有广阔的发展前景。     

山区坡耕地还林宜选树种南酸枣

为确保实施退耕还林成效,实现林业工程建设目标,选择合适的造林树种是关键因素之一.祁门县从众多的乡土树种中筛选出了南酸枣、枫香、光皮桦等适合退耕还林的优良速生树种,其中以南酸枣适应性广、生长快、生态功能强,易为林农接受,宜推广为皖南山区坡耕地造林的可选树种.     

枫香育苗造林技术

枫香,为金缕梅科落叶大乔木,淮河以南海拔1 500米以下山坡、路旁均可生长,树干通直,加工出材率高,还是培植食用菌的重要段木资源,又是较好的观赏绿化树种.2003年,桐城市林业开发公司租用农田5亩培育枫香苗,土地租金、种子、肥料、农药用工及管护等,每亩平均育苗费为1 200元.今春每亩产苗2.5万株,产值达3 700元,不仅经济效益可观,而且为全市今春近千亩(折算)枫香造林提供了随时取苗栽植的便利,提高了枫香造林的成活率.现就枫香育苗和造林的技术要点介绍如下.     

九连山常用乡土树种生长比较及造林效果探讨

对广东省连平县在生态公益林建设中常用的乡土树种生长情况进行了调查,并对带内人工造林树种和带间天然留存树种的造林效果进行了综合分析。结果显示：在人工铲带保留带间天然阔叶树种的造林方式下,带内人工造林的4种常用的乡土树种生长对比,酸枣生长最快,红锥次之,再次为火力楠,荷木生长较慢。此外,林分中存有大量天然起源的山鸟柏、樟树、米锥、枫香等树种,其中山乌桕、樟树和米锥的数量较多,且生长表现较好。总体造林效果良好,形成了以乡土树种为主的乔木层达到了郁闷状态,林内生物多样性保护完好,灌木层生长稳定,初步形成了较稳定的复层结构。     

枫香与杉木混交林、枫香纯林生产力研究

<正>安徽省旌德地区人工造林树种主要以杉木、马尾松等针叶树种为主。造林树种单一,使得林区针叶化明显,树种结构不合理,不仅难以满足国民经济建设对木材多方面的需求,而且还引起林地生境恶化,林地肥力下降等系列生态问题。1994年以来,旌德县蔡家桥林场开展了枫香苗木培育造林研究,基本掌握     

乌兰察布盟人工造林适地适树探讨及林业区划的修订

通过对乌兰察布盟现有人工造林树种分布及其适应性的研究，根据气候、土壤等因子，综合判定各树种适应范围，从而解决人工造林适地适树问题，并以此为基础对原有林业区划进行修订。     

Canopy management possibilities for arboreal Leucaena in mixed sorghum and livestock small farm production systems in semi-arid India

A major problem for small farmers in the semi-arid tropics is the chronic shortage of fodder for draft animals. Leucaena leucocephala has improved productivity in many places in India and in various cropping systems, usually as either a pure crop or in a hedgerow alley-cropping configuration. Mixed cropping with arboreal forms is seldom seen. For off-season fodder production, hedgerows have the disadvantage of being open to unmanaged browsing when unfenced (as is usual). Arboreal forms are generally far less vulnerable. In this paper, the components of production of sorghum and arboreal Leucaena are measured under different intensities of canopy lopping. The most productive management system of those examined was pollarding of the Leucaena at the time of under-sowing with sorghum. In a year with less than 50% of average seasonal rainfall, this system gave a yield of 4.6 tonnes/ha/yr fresh wt fodder and 3.8 tonnes/ha/yr dry wt. of fuel harvests, while increasing the standing crop of wood by 1.8 t/ha/yr and retaining a yield of sorghum grain equivalent to 46% of pure sorghum cropping; the LER of this system was 1.35. Cash values of the alternative management systems were estimated, including the discounted Net Present Value of the standing crop of timber. Maximum value was attained with unlopped pure crop Leucaena followed by pollarded Leucaena with sorghum; pure crop sorghum achieved a lower value. These results demonstrate both the high productivity of Leucaena/sorghum based systems, and the stability of production even in poor rainfall conditions. Pollarding transferred the high future value of Leucaena timber to the present value of sorghum grain and fuelwood.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

天牛体内纤维素酶研究进展

文章综述近年来国内外有关天牛体内纤维素酶的研究进展,主要包括:天牛体内纤维素酶的来源、不同天牛种类纤维素酶的性质、纤维素酶抑制剂、纤维素酶同工酶、纤维素酶基因以及天牛体内纤维素酶活性变化与寄主的关系,并展望了未来的研究方向。     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Trade-Offs in Forest Utilization from a Sustainability Perspective

Abstract

A sustainable use of forests may be conceived of differently by different scientific disciplines. An underlying definition of sustainability is therefore central to the understanding of any analysis on the subject. This paper approaches the idea of sustainability from an economic perspective. The interpretation of sustainability in terms of concepts such as efficiency, equity and welfare are initially described. Empirical research aiming at obtaining basic elements of economic sustainability analyses is subsequently outlined. Finally, the implications for applied welfare and sustainability analysis at different economic and geographical levels of aggregation are discussed     

Modeling spatial variability and pattern of rust and brown eye spot in coffee agroecosystem

The advent of Precision Agriculture has made possible the analysis of complex spatial patterns of plant disease epidemiology considering statements of integrated disease management. The objective of this work was to use geostatistics, statistics and geographical information systems to characterize the structure and magnitude of spatial dependency of rust (Hemileia vastatrix) and brown eye spot (Cercospora coffeicola) incidence and severity in coffee agroecosystem cultivated with Catuai Vermelho IAC-99 (Coffea arabica L.). Evaluations of incidence and severity of rust and brown eye spot were accomplished at 67 georeferenced points arranged in 6.6202 ha of coffee crop, in the years of 2005, 2006 and 2007. Exponential models of covariance enabled the characterization of the magnitude and structure of rust and brown eye spot spatial variability in the evaluated dates. Ordinary block kriging presented satisfactory performance to map rust and brown eye spot outbreaks based on kriging error coefficients. Kriged maps enabled the visualization of intensity of rust and brown eye spot in each evaluation date. Assessments of incidence and severity presented highly statistical correlation based on linear regression models, also confirmed by the spatial variability of kriging maps. Kriging maps of rust and brown eye spot enabled to observe that intensity of disease was dispersed in foci patterns along the coffee plantation, indicating that the current strategy of disease control based in total area may be replaced by site specific disease management, with less environmental impact and sustainability of coffee crop, according to statements of integrated disease management and precision agriculture.     

Nutrient cycling and growth in forest ecosystems of south western Australia: Relevance to agricultural landscapes

Nutrient and hydrologic cycles in harvested native forests in southern Australia are largely balanced. For example, we have little or no evidence of any decline in nutrient capital or availability in harvested forests. Short-term and small-scale reductions in evapotranspiration due to loss of leaf area after harvesting are adequately balanced at the landscape scale by large areas of regenerating or older-age forest. In contrast, agricultural systems on similar soils are a) dependent on large inputs of fertilisers to maintain growth and b) frequently subject to increasing salinity and waterlogging or other forms of degradation. The large-scale replacement of long-lived communities of perennial and often deep- rooting native species with annual crops or other communities of shallow-rooting species might be better managed within the framework of knowledge developed from studies of native plant communities. However, application of such a mimic concept to systems of low natural productivity is limited when agricultural systems require continued high productivity. Nonetheless, the mimic concept may help in developing sustainable management of agriculture on marginal lands, and contribute to the nutritional resilience of agroecosystems. Relevant characteristics for mimic agroecosystems in south western Australia include: high species diversity, diversity of rooting attributes, utilisation of different forms of nutrients (especially of N and P) in space and time, and the promotion of practices which increase soil organic matter content. This revised version was published online in June 2006 with corrections to the Cover Date.     

Native woody species regeneration in exotic tree plantations at Munessa-Shashemene Forest,southern Ethiopia

Regeneration of native woody species was studied in the plantations and the adjacent natural forest at Munessa-Shashemene Forest Project Area, Ethiopia. The aim of the study was to test the hypothesis that tree plantations foster regeneration of native woody species. A total of 60 plots, having 10 × 10 m area each, were studied in monoculture plantations of 4 exotic species (Cupressus lusitanica, Eucalyptus globulus, E. saligna, Pinus patula) and an adjacent natural forest. Ages of the plantations ranged between 9 and 28 years. Soil seed bank analysis was also undertaken from soil samples collected in each of the 60 plots to examine the similarity between the soil seed flora and aboveground vegetation. A total of 56 naturally regenerated woody species were recorded beneath all plantation stands with densities ranging between 2300 and 18650 individuals / ha in different stands. There was a significant difference among plantation stands with regard to understorey density (standard deviation: 4836 ± 1341). Vegetation diversity was assessed through analyses of floristic composition, species richness and abundance. Generally, seedling populations were the most abundant components of the regeneration in most of the plantation stands, forming 68 % of the total regeneration count in all stands. A total of 77 plant species represented by 44 herbs, 13 woody species, 8 grasses and 12 unidentified species were recorded in the soil seed bank from all stands. Similarity between the soil seed bank and aboveground flora was very low implying that the role of soil seed banks is negligible rather dispersal plays an important role in the process of regeneration. These results support the concept that forest plantations can foster the regeneration of native woody species, thereby increasing biological diversity, provided that there are seed sources in the vicinity of the plantations.     

Trees and shrubs as sources of fodder in Australia

Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline.     

Measurement of Green Plank Shape for Prediction and Elimination of Compression Wood

The objective of this study was to predict the amount and the distribution of compression wood (CW) within a Norway spruce [ Picea abies (L.) Karst.] plank based on green plank curvature. The findings indicated a possibility of predicting the longitudinal distribution of CW from the green plank curvature. Areas free from CW showed a typical concave shape in relation to the centre of the log, while CW was present when a convex shape was shown. The larger the magnitude of convex curvature, the higher the concentrations of CW that could be found, and a larger fraction of dried planks was rejected due to excessive warp. This study also determined what information can be used to eliminate areas of high concentrations of CW by cutting and how cutting affects the grading results with respect to warp. Over 50% of the plank length showing a high concentration of CW (>30% of the cross-cut volume) was successfully cut off. Cutting strategies based on predicted CW concentrations resulted in a 10-40% increase in accepted plank length.