Maximally selected two-sample statistics as a new tool for the identification and assessment of habitat factors with an application to breeding-bird communities in oak forests

Near-natural forest management is one of the major principles of modern forestry in central Europe. A measure commonly used for the assessment of logging is the occurrence and density of character species typical for the local biotope. Near-natural forest structures can be designed only when sufficient knowledge about the relationship between species and habitat factors is available. We suggest the use of simple cutpoint regression models for the derivation of statistically valid rules of thumb. The methodology is applied to bird and structure data of ancient and present oak coppices with standards to demonstrate its practical application. The cutpoints are derived from estimates of break points by means of maximally selected two-sample statistics, and their validity is judged by multiple test procedures. Detailed results are presented for character species and their relationships to the environment. We show that, for example, the tree pipit (Anthus trivialis) is missing in stands with more than 40% canopy overstorey, whereas this species can be regularly observed in more open stands. For the tree pipit, the analysis is illustrated by means of a free software package.     

Costs of harvesting, transportation and milling in the Brazilian Amazon: Estimation and policy implications

We estimate economic cost functions for timber harvesting, transportation and milling in the Brazilian Amazon using a 2003 sample of 527 firms in both new and older frontier locations. We find that labor wage, distance from the forest to the processing location, type of equipment, and the type of the frontier all factor significantly in the total and marginal cost of each activity, and that predicted processing costs are not significantly different on new frontiers implying a lack of technology adoption as industry expansion into the Amazon has occurred. We also show that capturing economies of scale in logging by increasing average annual logging volumes by 50% and reducing the number of firms to about 1400 could lead to an industry wide cost savings of approximately US$90 million per year. Similar economies of scale are also present in log transport but not in processing. Further, if improved logging techniques allow harvest for an additional 1 month per year, for example through better planning, the industry could reduce logging costs by almost US$30 million. This points towards generating forest policies and economic conditions that encourage firm size growth, as opposed to those policies encouraging massive entry of small, unregulated and inefficient firms, and the adoption of management practices that allow for additional time in the forest.     

Discrepancies between ergosterol and the phospholipid fatty acid 18:2ω6,9 as biomarkers for fungi in boreal forest soils

Ergosterol and the phospholipid fatty acid (PLFA) 18:2ω6,9 are frequently used as fungal biomarkers in studies on soils, and in accordance with the ideal for biomarkers of microorganisms they are thought to turn over rapidly after cell death and lysis. These biomarkers should also show the same patterns and responses to perturbations of the studied system. Here, I report strong correlations, in natural boreal forests of contrasting fertility, between free ergosterol and PLFA 18:2ω6,9 (r=0.821, P=0.007, n=9). Surprisingly, ergosterol, but not PLFA 18:2ω6,9, appears non-responsive to both large-scale tree girdling, which interrupts tree belowground C allocation to ectomycorrhizal fungi, and to long-term N-loading, which may have negative effects on both mycorrhizal and saprotrophic fungi. These results, therefore, question the use of ergosterol to monitor effects of soil perturbations on fungi in the field, but do not put into question the use of the biomarker in natural forest ecosystems.     

Formation mechanisms and remediation techniques for low-efficiency artificial shelter forests on the Chinese Loess Plateau

The construction of artificial shelter forests (ASFs) has resulted in substantial ecological, economic, and societal benefits to the Chinese Loess Plateau (CLP). However, the health and benefits of ASFs are being increasingly threatened by the formation of low-efficiency artificial shelter forests (LEASFs). In this study, LEASFs are systematically analyzed in terms of their status, formation mechanisms, and developmental obstacles. The key restoration techniques and schemes were summarized to improve the quality and efficiency of LEASFs. LEASFs are formed by relatively complex mechanisms, but they arise mainly due to poor habitat conditions, improper tree species selections, mismatch between stands and habitat, extensive forest management measures, and human interferences. The restoration and improvement of LEASFs are hindered by water deficits, mismatch between stands and habitat, single management purpose, and low efficiency. LEASFs are becoming more complex due to their wide range, the challenges associated with their restoration, and insufficient technological measures for their restoration. The key techniques of the quality and efficiency improvement of LEASFs include basic forest tending methods, near-natural restoration, multifunction-oriented improvement, and systematic restoration. An understanding on the formation mechanisms of LEASFs and a scientific approach toward their restoration are urgently needed and critical for the ecological protection and high-quality development of LEASFs on the CLP. Based on these analyses, we recommend strengthening the monitoring and supervision of LEASFs, considering the bearing capacity of regional water resources, implementing multiple restoration techniques, promoting multifunction-oriented ecological development, and exploring new management concepts to achieve the sustainable development of ASFs on the CLP.     

桉树人工林与天然林土壤养分的对比研究

在野外调查取样和室内实验分析的基础上,对人工林与天然林的土壤养分进行比较分析,结果表明人工林土壤表层的有机质、全氮、全磷、全钾含量都明显低于天然林,反映了人工林对养分的旺盛需求和消耗,并且人工林还会造成土壤阳离子交换量的降低和土壤容重的增大。提出变炼山全垦为块状整地、轮栽并适当休闲养地、提高人工林生物多样性、建立复杂的人工林群落等措施,以实现桉树人工林土壤养分平衡与生态系统的良性循环。     

Sustainable plantations of high-yield shape Eucalyptus trees for production of fiber: the Aracruz case

The importance of planted forests for human communities is evident today because of the increase in world population year after year. In order to supply the constantly increasing requirements for wood for fiber, energy, civil construction, resin, latex, and other needs, new forests have been established by adopting new concepts of technology. These forests, especially those with fast-growing and short-rotation species, incorporate the objectives of quality, productivity, and environmental protection.The Eucalyptus plantations established by Aracruz Celulose S. A. to produce pulpwood have strongly contributed to the evolution of forest science, especially in the fields of silviculture, propagation, improvement, genetics, biotechnology, nutrition, environment, and disease control related to eucalypt species. Significant investments in research and development were required, as well as technological adaptation to the local conditions. Results of these investments in productivity and quality defined the technical feasibility to build a pulp industry and its expansion to reach 1,025,000 t/yr of bleached pulp.As a result of these advances, the mean increment of pulp productivity has been improved significantly -- from 5.9 air-dried t/ha/yr to 10.9 t/ha/yr (Fenton and Romero 1995; Bertolucci et al. 1995). This became possible by selecting trees more adapted to each site, with high yields of high quality fiber, and with eucalypt clonal plantations with an average rotation age of 7 years. Additional studies of Aracruz have promoted advances in industrial processes, as well as definition of fiber characteristics of mother trees to be in attendance with requirements of markets, thus providing an important competitive advantage (Campinhos and Cláudio-da-Silva 1990).The care for the environment -- both forest and industrial -- has been always present and has been the key point for the good performance of the project. This fact has created a world emulation that strongly contributes to decreasing the pressures on native forests, as a result of the consequent utilization of smaller land areas to produce a desired wood volume. This total project is an example of domestication (Eldridge et al. 1994) of the forest genus Eucalyptus with exceptional qualities and represented by more than 500 species and hybrids (Campinhos et al. 1992).     

玉溪大栗园人工混交林混交模型初步研究

用蓝桉、麻栎、藏柏、山樱桃、圣诞树、山合欢等作混交树种，在玉溪大栗园开展了8种人工混交林混交模型的试验研究，依据Ii=P1h/H+P2d/D+P3v／V计算混交模型的选择指标，用I标=I平均+aδn计算出混交模型的选择标准为3．0175。据此对参试的混交模型进行评定，结果以圣诞树×山樱桃带状混交效果最好，其次是藏柏×山合欢、藏柏×圣诞树带状混交。3种入选的混交模型的配置方式为混交林株行距为1m×2m的带状混交，混交林配置树种以50株为1行，4行200株为一混交模型，行与行随机排列。试验结果还表明混交林中各树种单株的生长量比纯林高。     

巴西人工林集约经营和管理考察报告

巴西现有人工林６００万ｈｍ＾２，约３０％的木材取自人工林。总结其生产经验，主要有：（１）根据国同外市场需求，实行定向培育；（２）企业可以自主告自主采伐，自主加工利用，自主进出口贸易，实行林工商一体 化的经营体制；（３）十分重视科技投入和科技进步，提高林地生产力，降低生产成本；（４）注重环境保护工作。     

中国金小蜂科一新纪录属及新纪录种记述

对采自新疆伊犁河谷西天山野果林的金小蜂科一中国新纪录属爪突金小蜂属(Micradelus Walker,1834)和一新纪录种尖腹爪突金小蜂(Micradelus acutus Graham,1969）进行详细的外部形态特征描述,编制该属世界已知种的检索表,并提供该种的成虫形态特征图以及ITS2和28S rDNA序列信息;结合形态学和分子分析结果,认为将爪突金小蜂属归入寡节金小蜂亚科更合适。所有研究标本均保存在新疆大学生命科学与技术学院昆虫标本馆（ICXU）。