何谓“对乌纱帽负责任”

长期以来,在党和国家的政治生活乃至人们的日常生活中经常出现涉及负责或负责任一词的种种提法,如:对党和国家负责、对人民负责、对子孙后代负责、对事业负责、对工作负责、对安全生产负责、对产品质量负责、对同志负责、对读者负责、对消费者负责,如此等等,却很少出现     

何谓"对乌纱帽负责任"

长期以来，在党和国家的政治生活乃至人们的日常生活中经常出现涉及“负责”或“负责任”一词的种种提法，如：对党和国家负责、对人民负责、对子孙后代负责、对事业负责、对工作负责、对安全生产负责、对产品质量负责、对同志负责、对读者负责、对消费者负责，如此等等。却很少出现“对乌纱帽负责任”的提法。     

何谓“对乌纱帽负责任”

长期以来,在党和国家的政治生活乃至人们的日常生活中经常出现涉及“负责”或“负责任”一词的种种提法,如：对党和国家负责、对人民负责、对子孙后代负责、对事业负责、对工作负责、对安全生产负责、对产品质量负责、对同志负责、对读者负责、对消费者负责,如此等等。却很少出现“对乌纱帽负责任”的提法。     

联邦德国森林效益的和谐化

各国林业界人士言必称联邦德国,近年来连许多外界人士也对联邦德国的林业成就津津乐道。一些人对联邦德国的森林以生产木材为主还是以保护自然或提供游憩场所为主的问题持不同的看法。比如,人们可以援引1975年颁布的“联邦森林法”:“由于森林的经济用途(木材);由于其对环境,特别是对自然平衡的持久生产能力、对气候、对水分平衡、对净化大气、对土壤肥力、对景观、对农业和社会,以及对居民的游憩有重要意义,要保持森林,必要时     

马尾松群落的种间联结性研究

以马尾松群落为研究对象,采用方差比率法、x~2检验、Pearson相关和Spearman轶相关检验对乔木层5个主要树种、灌木层25个优势树种、草本层16个优势物种的种间联结性及相关程度进行定量研究。结果表明:马尾松群落乔木层、灌木层、草本层总体种间关系分别表现为显著负关联、不显著正关联和显著负关联;x~2检验统计显示乔木层、灌木层、草本层负关联种均占较大优势,分别占总种对数的40.00%、66.67%、61.67%,正关联种对数次之,分别占总种对数的10.00%、33.33%、38.33%,无关联种对数较少;Pearson相关检验显示乔木层有正关联种对4对、负关联种对6对、正负关联比为0.67,灌木层有正关联种对113对、负关联种对187对、正负关联比为0.60,草本层有正关联种对51对、负关联种对69对、正负关联比为0.74;Spearman轶相关检验显示乔木层有正关联种对3对、负关联种对7对、正负关联比为0.43,灌木层有正关联种对111对、负关联种对152对、无关联种对37对、正负关联比为0.73,草本层有正关联种对46对、负关联种对65对、无关联种对9对、正负关联比为0.71。     

对土壤线虫有害对抗体的研究

本文主要介绍了土壤线虫的有害对抗体,包括几丁质和生物对抗体(真菌对抗体、细菌对抗体、捕食性线虫、无脊椎动物对抗体和自由生存的线虫),同时介绍了影响土壤线虫和这些对抗体的因素.     

自然保护区周边社区居民对保护区依赖与态度的关系研究

通过对广西林业系统自然保护区周边社区居民对保护区依赖情况与态度调查,结果显示,社区居民对保护区的依赖程度并不是很高,目前保护区周边社区居民对保护区的支持率较高。但不同的保护区的周边社区居民对保护区的支持率存在明显差异。社区居民对保护区资源的依赖与态度呈现出明显的负相关性,即随着社区居民对保护区资源直接依赖程度的降低,其对保护区态度越积极。     

对集体林权制度改革的一点看法

文章对集体林权制度改革对促进生态保护的影响进行了阐述;并对如何消除林改对生态保护带来的负面影响提出了相应措施;对相关的配套改革思路进行了探讨。     

尾叶桉芽苗不同真叶分床上袋育苗试验初报

在苗田对尾叶桉芽苗不同真叶期分床上装试验表明；在同样育苗时间内，不同真叶的幼苗分床上袋对培育的苗木高生长量，有着极显著的影响，4对真叶的小苗，移载后培育出的苗木，在高度和质量上，明显优于6对、5对、3对、2对真叶小苗移栽所培育的苗木。     

双戊烯合成对伞花烃的工艺研究

通过气相催化反应，使双戊烯合成对异丙基甲苯即对伞花烃，选择了适宜的催化剂，探讨了反应温度、催化剂活性组分浓度等因素对产物中对伞花烃含量的影响，并对催化剂的重复使用性能进行了考察，得出了适宜的工艺条件，在此条件下，产物中对伞花烃的含量为79.6%，通过精馏可得到高纯度（97.8%）的对伞花烃.     

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。     

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.     

瓜州绿洲植被退化原因及保护对策

瓜洲县近年来人口数量增长和土地开发规模过大,成为水资源紧张、植被退化、生态环境质量下降的重要原因之一,对绿洲农业生产和人居环境影响很大,因此,严格控制人口数量的增长和土地开发规模,大力发展节水农业,保障生态供水,加强对现有植被的保护,维护生态平衡,是瓜洲县实现可持续发展必须认真考虑的问题。     

Using degree-day accumulations and host phenology for predicting larval emergence patterns of the olive psyllid, <Emphasis Type="Italic">Euphyllura phillyreae</Emphasis>

The olive psyllid, Euphyllura phillyreae Foerster is one of the most destructive pests on buds and flowers of olive tree (Olea europaea L.) in May when the olive growers cannot apply any insecticides against the pest. Temperature-dependent development of the psyllid was studied at constant temperatures ranged 16–26°C. A degree-day (DD) model was developed to predict the larval emergence using the weekly cumulative larval counts and daily mean temperatures. Linear regression analysis estimated a lower developmental threshold of 4.1 and 4.3°C and a thermal constant of 164.17 and 466.13 DD for development of egg and larva, respectively. The cumulative larval counts of E. phillyreae approximated by probit transformation were plotted against time, expressed as the sum of DD above 4.3°C, the starting date when the olive tree phenology was the period of flower cluster initiation. A linear model was used to describe the relationship of DDs and probit values of larval emergence patterns of E. phillyreae and predicted that 10, 50 and 95% emergence of the larvae required 235.81, 360.22 and 519.93 DD, respectively, with errors of 1–3 days compared to observed values. Based on biofix depends the development of olive tree phenology; the DD model can be used as a forecasting method for proper timing of insecticide applications against E. phillyreae larvae in olive groves.     

我国竹类植物种质保护体系的适度理念研究

竹类是一类具特殊生长习性与生长型的植物,其分布范围广泛、有性生殖脆弱而无性繁殖发达,易于受到人为和自然因素的影响而沦为小种群或濒危物种。本文从小种群近交危害与集合种群上分析了竹类种质保护的适度思想,即适宜的局域种群与集合种群结构度是优化竹类野生种质保护的重要依据;并从区域相对封闭生态系统结构度与竹类种质稳定性上分析了野生种质适度保护的策略;最后从加强竹类种质种群生态学特征的编目清查、自然野生栖息地就地保护、竹类种质保存圃建立与完善,以及竹类原料林的定向培育4方面阐述了竹类种质的适度保护体系。     

Eugenol and thymol, alone or in combination, induce morphological alterations in the envelope of Candida albicans

The envelope of Candida albicans, with its outermost array of macromolecules protruding towards the environment, is pivotal to the expression of major virulence factors such as adhesiveness, and the morphological transition to hyphal form. We tested the anticandidal activity of eugenol, main component of clove oil, and thymol, main component of thyme oil, alone or in combination, by investigating their ability to interfere with the architecture of the envelope of C. albicans. Both molecules alterated the morphogenesis of the envelope, but the effects of thymol were more pronounced than those of eugenol. Certain combinations of the two molecules led to a synergistic effect, which is interesting in the view of potentiating their inhibition of C. albicans colonisation and infectiousness.     

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.     

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