Relationships between earthworm communities and burrow numbers under different land use systems

This study addresses the influence of three different land use systems (continuous maize, pasture/maize rotation, permanent pasture) on the relationships between earthworm populations and the number of earthworm burrows quantified in a soil profile. Quantified burrows were limited to those observable by the naked eye (i.e. >2 mm in diameter) and enumerated earthworms were limited to those which could have created the observable burrows (i.e. >0.3 g).The results were combined with data from the literature coming from different geographical regions. This study showed that earthworm abundance decreased with the increasing land management intensity (maize crop vs. pasture), while the number of burrows could be higher or similar under maize compared to pasture. Under maize, despite lower earthworm abundance and the annual destruction of the burrows by tillage, the number of burrows was almost as high as under pasture. This absence of a relationship between burrow numbers and earthworm abundance was observed in the soil profile and for each layer of the profile for each land use system. Furthermore, the burrow number/m⁻² per earthworm strongly varied depending on land use and was far higher under maize when compared to pasture (74 vs. 7). Therefore, a power-law type relationship was clearly established between burrow number/m⁻² per earthworm and earthworm abundance. This power type relationship was also observed when including data from the literature although it followed a different mathematical model. These results were explained by (i) increased earthworm burrowing activity (i.e. an increase in the number of burrows produced by each earthworm) under maize, and (ii) the dynamics of burrow number under pasture (i.e. decreased burrowing activity and burrow destruction process); both results of food accessibility combined with inter-individual competition. The results of the study suggest that farmers should not use the number of pores as an indicator of earthworm abundance, but as an indicator of earthworm activity, which could be integrated in an indicator of soil quality.     

液压前叉减振器示功图分析

分析了液压前叉减振器与汽车筒式减振器示功图之间的差别以及影响液压前叉减振器示功图形状的主要因素，根据示功图的特点提出了对其进行试验和评价的几点看法。     

对CNMARC字段指示符的若干认识和思考

文章结合著录工作实践对CNMARC指示符的赋值问题提出一些看法及建议。     

健康成年黄牛血液动力流变学生理指标的无创检测

首次应用ＸＸＧ－Ａ型心血管功能测试仪对２９头健康成年黄牛进行了无创检测。经数理统计分析，获得成年黄牛血液动力流变学重量指标２５项，分别从心血管功能，血液流变状态和微循环机能等方面反映机体生理机能素质。为黄牛育种、改良及其生理、病理研究提供了重要的数据。     

论河南省林业科技进步评价指标体系

科技进步评价指标体系在科技进步评价中发挥越来越重要的作用,本文对河南省林业科技进步评价指标体系的建立和应用等方面进行了探讨。     

谈森林可持续经营标准的重点及意义

介绍了森林可持续经营的标准和指标,对其重点和意义做了概述。     

森林经营可持续性评价方法

森林经营可持续性评价是当前森林可持续经营研究和实施中亟待解决的一个难题。本文就森林经营可持续性评价指标的筛选、指标的无量纲化、指标权重的确定和可持续性水平综合评价等方法进行了探讨。     

四川林业产业统计监测制度研究

本文讨论了四川省建立林业产业统计监测制度的必要性和林业产业统计指标体系的建立;确立了统计范围和统计报表的构成;提出了统计数据的收集方法。     

Dead wood in European beech (Fagus sylvatica) forest reserves

Data were analysed on the volume of dead wood in 86 beech forest reserves, covering most of the range of European beech forests. The mean volume was 130 m³/ha and the variation among reserves was high, ranging from almost nil to 550 m³/ha. The volume depended significantly on forest type, age since reserve establishment and volume of living wood. More dead wood was found in montane (rather than lowland/submontane) reserves, longer-established reserves (time since designation) and reserves with higher volumes of living wood.

On average, fallen dead wood contributed more to the total dead wood volume than standing dead wood. The percentage of dead wood that was standing was almost twice as high in montane than in lowland/submontane forest reserves (45% versus 25%). The volume of dead wood at selected sites changed considerably over time. The fluctuations were significantly higher in lowland/submontane than montane reserves, possibly connected with differences in the disturbance regimes and especially damage caused by windstorms. In NW Europe, the blow down of formerly managed, even-aged stands led to extraordinary high volumes of dead wood shortly after reserve establishment.

The implications for forest management and biodiversity conservation are discussed. An increase in dead wood volumes must be carried out in accordance with the local/regional forest type and disturbance regime. Thus, in order to fulfil the requirements of as many wood-depending organisms as possible, it is important to preserve not only larger amounts of dead wood, but also dead wood of different types and dimensions as well as securing a long-term continuity of dead wood.     

Relations between selected geomorphology features and tree species diversity of forest ecosystems and interpolation on a regional level

The presented paper analyses the relations between four features of geomorphology, i.e. aspect, slope, elevation and type of terrain, and tree layer diversity of forest ecosystems. The forest stand diversity is quantified by nine species diversity indices (N0, R1, R2, H, N1, N2, E1, E3, E5). The data used in this study come from the regional forest inventory of the Forest School Enterprise, Technical University Zvolen, Slovakia. Within this inventory, 26 permanent tracts were established in the systematic grid of 2×2 km, whereby a total of 120 sample plots were created on which 1,728 trees were measured. Analyses showed that species diversity is closely related only to elevation. However, the relationships of the individual species diversity indices to elevation are loose since the correlation coefficients do not exceed values of 0.30–0.40. The second part of this work presents spatial interpolation of species diversity degrees on a regional level using geostatistical methods. For this regionalisation, we used an indicator kriging. The final kriging map was found to be a suitable tool for the interpretation of tree species diversity over the investigated area.