Nature reserve selection on forest fragments in a suburban landscape (Rome, Central Italy): indications from a set of avian species

A set of avian forest species, known from the literature as fragmentation-sensitive, was considered as the target in nature reserve planning following a conceptual framework. Their abundance was investigated in an 'archipelago' of oak woodland fragments embedded in a suburban landscape matrix of central Italy. None of the four species were found in any wood fragment smaller than 10 ha. The presence/absence analysis of woodland fragments studied showed that the study species were present, however, in larger fragments, highlighting the strategic role of habitat size and isolation for the persistence of these species at local scale. Species numbers and their total abundance were significantly and directly correlated to overall species richness of each fragment: in this landscape context our study species shows characteristics of serving as focus and surrogate species of bird richness. The selected species are area-sensitive and poor dispersers: however, they are still relatively widespread, at a regional scale. Although the abundance of individual species may be affected by stochastic factors, total abundance of this forest bird guild may constitute a useful dependent variable that can provide rapid quantitative data needed for planning strategies at local scales.     

利用气质联用技术对木材进行分类和鉴别

采用气质联用技术(GC-MS)对不同类及不同产地的同类木材进行分析,结果发现:不同类木材的总离子流图差别非常明显,相关系数非常小;而同类木材总离子流图基本相同,相关系数较高,并且都含有相同的特征峰.上述实验结果表明,鉴别木材有2种有效方法:一是利用相关系数,即相关系数大于0.900的可认为是同类木材;二是根据特征成分,即每种木材在其总离子流图中都有一组特征峰.     

Changes in Land Cover and Parcel Size of British Lowland Woodlands over the Last Century in Relation to Game Management

The area and number of woodlands within landscapes managed for shooting pheasants and other lowland game birds are contrasted with those not managed for game. The study locations were sample 1-km squares from the Countryside Survey (CS), a survey of the land cover of Great Britain. Two-hundred-and-thirty-two appropriate CS squares were divided into game and non-game squares on the basis of evidence of management for game. No significant differences were found in changes in woodland area or parcel number during the periods 1984-90 and 1990-98. Twelve matched pairs of game and non-game squares were selected, and the disposition of woodland was taken from maps of the 1870s, 1940s, 1960s and 1980s, recording total area, number of woodland parcels and parcel sizes. The number of parcels of woodland in game squares increased more than that in non-game squares during the period 1960s-1980s, but mean parcel size changed little. Landscapes where management for game has taken place have retained a greater proportion of the woodland present in the 1870s. It seems that game shooting has encouraged landowners to retain existing woodlands, and to plant new ones, during the period 1960s-1980s.     

Changes in Land Cover and Parcel Size of British Lowland Woodlands over the Last Century in Relation to Game Management

The area and number of woodlands within landscapes managed for shooting pheasants and other lowland game birds are contrasted with those not managed for game. The study locations were sample 1-km squares from the Countryside Survey (CS), a survey of the land cover of Great Britain. Two-hundred-and-thirty-two appropriate CS squares were divided into game and non-game squares on the basis of evidence of management for game. No significant differences were found in changes in woodland area or parcel number during the periods 1984-90 and 1990-98. Twelve matched pairs of game and non-game squares were selected, and the disposition of woodland was taken from maps of the 1870s, 1940s, 1960s and 1980s, recording total area, number of woodland parcels and parcel sizes. The number of parcels of woodland in game squares increased more than that in non-game squares during the period 1960s-1980s, but mean parcel size changed little. Landscapes where management for game has taken place have retained a greater proportion of the woodland present in the 1870s. It seems that game shooting has encouraged landowners to retain existing woodlands, and to plant new ones, during the period 1960s-1980s.     

Impact of Eucalyptus camaldulensis plantation on an alluvial soil in south eastern Botswana

This paper examines the impact of a 33‐year plantation of Eucalyptus camaldulensis on an alluvial soil in Gaborone, south eastern Botswana, by comparing the soil under the plantation with similar soil under an adjoining native savanna woodland dominated by Acacia karoo. Soil clay content was significantly higher in the plantation soil in both the 0–10 cm and 10–20 cm layers. There were no significant differences between soil under the two ecosystems with respect to the levels of organic matter, exchangeable potassium and available phosphorus. Despite the higher clay contents of the plantation soil, exchangeable calcium and magnesium and pH were higher in soil under the native woodland. This suggests that E. camaldulensis immobilizes soil nutrients faster and that plantation nutrient cycles are less efficient than in the native Acacia woodland. Consequently, soil nutrient deficiency will limit plantation productivity after the first few rotations. It is important to adopt tree harvesting techniques that reduce drain on soil nutrients at the end of a plantation rotation.     

Comparison of the structural stability of pasture and cultivated soils

The structural properties of two neighbouring soils from the NW of Spain were evaluated in order to elucidate the effect of management on the soil structural quality and soil organic carbon turnover. The two soils were developed on granite under a warm and humid climate, but differed in land use (pasture and cultivation). The pasture soil had more favourable structural properties than the cultivated soil, showing lower bulk density, higher porosity and water retention. Also, the pasture soil showed a higher mean aggregate diameter and aggregate stability against mechanical agitation in water, as well as lower soil loss under simulated rainfall. This increased structural stability of the pasture soil could be attributed to its higher soil organic matter (SOM) content. The effect of soil use and aggregate size on SOM mineralization was also investigated. Laboratory incubation experiments were conducted with 1-5 mm aggregates and disaggregated <1 mm soil. More C-CO(2) was released by SOM mineralization in the pasture soil than in the cultivated soil, thus indicating a higher microbial activity in the pasture soil. The respiratory quotient (C-CO(2)/Corg) was also higher in the pasture soil, which means that SOM in this soil is more accessible to microbial decomposition. Nevertheless no significant differences were observed between organic C mineralization in the disaggregated <1 mm soil and the undisturbed 5-1 mm aggregates. The overall results demonstrate the need to maintain adequate levels of OM by adding organic amendments or adopting lower impact cultivation practices such as reduced tillage.     

Intersection reservations as habitats for meadow butterflies and diurnal moths: Guidelines for planning and management

Regularly managed road verge environments, such as intersection reservations, i.e. non-linear grassland patches surrounded by roads and ramps, form potential habitats for plant and insect species dependent on semi-natural grasslands. The first objective was to compare the Lepidoptera communities of intersections to other open biotopes (semi-natural grasslands, abandoned fields and field verges) in order to determine whether this is true under the present management regime. The second objective was to characterise environmental factors explaining the possible differences between the habitat groups and the most important factors associated with high species richness and population sizes in intersections. Between 2002 and 2003, a total of 97 species and 7250 individuals were recorded in transect counts on 17 sites on both intersections and control areas in SE Finland. There were more species and butterfly individuals in the control sites, the differences being due to the surrounding environment and young age of most intersection habitats. Old intersections with high plant species richness and natural vegetation exhibited the highest Lepidoptera species richness, while soil moisture and mowing intensity were the most important factors explaining Lepidoptera abundance. The spreading of a thick layer of top soil rich in nutrients and the use of non-native seed mixes rich in grasses during the construction phase should be avoided and late summer mowing management combined with the removal of cut material should be applied in intersections.     

反观木在中国传统建筑文化中的情结

主要是针对"木"在中国传统建筑文化中的反面探讨,从五个方面分析了"木"存在的缺点,然后指出要辨证地看待"木"在中国传统建筑中的作用,以便更好地继承与发展"木"在现代建筑设计中的应用与实践。     

Human impact on the abundance of useful species in a protected area of the Brazilian Cerrado by people perception and biological data

Studies about relationships between people and landscapes have shown that local communities can affect the abundance of plant species useful to humans, which raises the question of how landscape management processes might modify the abundance of useful plant species in a forested area. We addressed this issue based on people perception and biological evidence. This study was undertaken in the Araripe National Forest, a protected area of sustainable use of natural resources in Brazil. Our results showed that the studied landscape experienced modifications in abundance of species caused by management processes. For instance, phytosociological data for the managed areas showed a greater abundance of the more salient useful species compared with useful species that have lower local importance. The comparison of historical and current aerial images of the landscape indicated that plant density had increased in forested managed areas where agricultural practices were stopped. Despite this, local perceptions indicated that the abundance of most of the useful plant species in the managed areas had decreased over time.     

CS/h-BN/APP层层自组装涂层阻燃杨木的研究

为提高杨木的阻燃性能,利用带正电性的壳聚糖/六方氮化硼(CS/h-BN)聚电解质溶液,以及带负电性的聚磷酸铵(APP)溶液,基于层层自组装(LBL)技术,通过两聚电解质溶液之间的静电吸附作用,在木材表面成功制备出具有良好阻燃性能的CS/h-BN/APP薄膜涂层.结果表明:所制备的涂层均匀分布在木材表面,且具有良好的附着力;涂层阻燃木材试件的热释放速率、烟释放速率显著降低,第2放热峰出现时间晚于未处理木材试件,且在燃烧过程中的残余物质量始终高于未处理木材试件,完全燃尽时间则比未处理木材试件多出约100s,阻燃效果随着自组装涂层数的增加而逐渐增强;涂层阻燃木材试件的CO、CO_2气体生成量明显降低,表明阻燃涂层能有效降低木材烟气及毒性气体释放;涂层阻燃木材试件较未处理木材试件更好地保持了木材本身的结构,显示出了良好的抵抗火灾能力.     

Trees and wood: working with natural river processes

A history of land clearance and riparian tree and wood management has resulted in limited riparian woodland and wood along British rivers. However, river management approaches are now being promoted that ‘work with natural processes’ to reduce flood risk through measures intended to restore, protect and emulate the natural function of catchments, rivers, estuaries and coasts. Wood has started to be reintroduced into river channels during river restoration and natural flood management activities, but this needs to be undertaken using appropriate quantities, locations and designs that mimic natural tree‐wood features. This paper reviews the knowledge that is needed to support wood reintroduction activities including (i) the characteristics of the riparian tree species and wood that are present; (ii) the importance of river size relative to that of trees and wood pieces; and (iii) the way trees, wood and geomorphic processes interact across rivers and floodplains of different energy and style.     

Farmers’ livelihood assets and adoption of sustainable land management practices in north-western highlands of Ethiopia

In Ethiopia, farmers’ adoption and continued use of introduced land management technologies have not been widespread to reduce soil erosion and soil fertility depletion to an acceptable level. An important set of factors in farmers’ use of improved agricultural technologies is generally known to be their possession of livelihood assets. This study examines the influence of ownership of livelihood assets in farmers’ decisions to use cattle manure as land improvement technology, which is currently being promoted by Ethiopia’s agricultural extension system. The study was conducted in Dangila woreda (district) in the north-western highlands of Ethiopia. Data were collected from a survey of 201 rural households from April to June 2011 and in October 2012. Logistic regression modelling and Chi-square and t-tests were used to analyse data. The findings show that plot distance from residence, number of livestock owned, use of dung for fuel, maize–vegetable–fruit intercropping, land to man ratio and perception of land tenure security were important determinants of manure use among the farmers. Existing and future local development interventions should focus on these factors to improve the farmers’ capability to invest in cattle manure application and sustainable land management.     

Construction resource/method factors influencing productivity for high rise concrete construction

Research among European countries had confirmed variance in productivity rates ascribed by construction planning engineers for identical operations. Similar differences in planned construction resource/method factors also had been identified. It is hypothesized that such variance may be due to differences in contractor preference, resulting from socio-economic and corporate objective impacts. Analysis of variance and correlation tests are used to examine this hypothesis on data obtained from French, German and UK contractors. Numerous construction resource/method factors are tested for their impact on mean productivity rates for principal high rise in situ concrete construction operations. Significant productivity rate variations are identified for reinforcement fixing and formwork erection, while variance in concrete placing productivity rates are not found to be dependent upon construction resource/method factors. Contractors seeking to improve productivity might wish to consider solutions for construction resource/method decisions that have been found herein to be related to higher productivity rates and (in some cases) lower costs.     

The effects of ply organization and loading direction on bending strength and modulus of elasticity in laminated veneer lumber (LVL) obtained from beech (Fagus orientalis L.) and lombardy poplar (Populus nigra L.)

The effects of ply organization and loading direction on bending strength and modulus of elasticity in laminated wood materials produced from 3 mm thick veneers, of beech (Fagus orientalis L.) and lombardy poplar (Populus nigra L.) placed one on top of the other in various arrangements were examined in this study. Kleiberit 303 (PVAc), a vinyl (polyvinyl acetate – PVAc) based glue was used in lamination. Eight hundred samples were prepared in order to measure oven-dry specific gravity, bending strength and modulus of elasticity values perpendicular and parallel to the glue line of a total of 10 different arrangements, eight of which have different laminated ply organizations, namely (AAAAAAA) (7A), (BBBBBBB) (7B), (ABBBBBA), (ABABABA), (AABBBAA), (AABABAA), (ABBABBA), (BABABAB), in which (A) represents beech wood and (B) represents poplar wood and the other two, which consist of solid beech and solid poplar wood in same dimensions as control samples. The samples were subjected to tests perpendicular and parallel to the glue line in accordance with the ISO 16978 standard. As a result of statistical analysis of the data obtained from the tests, the bending strength and modulus of elasticity values of solid woods both perpendicular and parallel to the glue line were observed to be smaller than those values of laminated woods made of the same species of woods. It was also observed that as contribution rate of beech in lamination increases, the bending strength and modulus of elasticity values increase.     

Modelling the Soil Moisture Deficits Developed under Grass and Deciduous Woodland: the Implications for Water Resources

The area of deciduous woodland in the UK is increasing as a result of Government policy, and studies suggest that this might result in reduced streamflow and groundwater recharge. Measurements of soil water content were carried out (a) at a site on a sandy loam soil, (b) under land covers of grass, and (c) in deciduous woodland. The data show that both the field capacity and wilting point of the soils were much less under the woodland than those under grass. In 1997, soil moisture deficits were developed down to a depth of 1 m under grass and in excess of 3 m under the deciduous woodland. A simple daily water-balance model was able to simulate the observed soil water contents and emphasised the importance of interception losses from the deciduous woodland canopy. For a 25-year period, the model predicted that the mean annual runoff and soil drainage for the woodland was less than half those for grass.     

The irradiation and ignition of wood by flame

The generally accepted models on the ignition of wood are not valid. So say the authors, who present an improved model, which correlates data on five different woods.     

Assessing land-use effects on water quality, in-stream habitat, riparian ecosystems and biodiversity in Patagonian northwest streams

Changes in land-use practices have affected the integrity and quality of water resources worldwide. In Patagonia there is a strong concern about the ecological status of surface waters because these changes are rapidly occurring in the region. To test the hypothesis that greater intensity of land-use will have negative effects on water quality, stream habitat and biodiversity we assessed benthic macroinvertebrates, riparian/littoral invertebrates, fish and birds from the riparian corridor and environmental variables of 15 rivers (Patagonia) subjected to a gradient of land-use practices (non-managed native forest, managed native forest, pine plantations, pasture, urbanization). A total of 158 macroinvertebrate taxa, 105 riparian/littoral invertebrate taxa, 5 fish species, 34 bird species, and 15 aquatic plant species, were recorded considering all sites. Urban land-use produced the most significant changes in streams including physical features, conductivity, nutrients, habitat condition, riparian quality and invertebrate metrics. Pasture and managed native forest sites appeared in an intermediate situation. The highest values of fish and bird abundance and diversity were observed at disturbed sites; this might be explained by the opportunistic behavior displayed by these communities which let them take advantage of increased trophic resources in these environments. As expected, non-managed native forest sites showed the highest integrity of ecological conditions and also great biodiversity of benthic communities. Macroinvertebrate metrics that reflected good water quality were positively related to forest land cover and negatively related to urban and pasture land cover. However, by offering stream edge areas, pasture sites still supported rich communities of riparian/littoral invertebrates, increasing overall biodiversity. Macroinvertebrates were good indicators of land-use impact and water quality conditions and resulted useful tools to early alert of disturbances in streams. Fish and birds having a greater ability of dispersion and capacity to move quickly from disturbances would reflect changes at a higher scale.     

Land use/cover dynamics and their effects in the Gerado catchment,northeastern Ethiopia

This paper analyses the land use/cover dynamics of land degradation through the interpretation of aerial photographs (1958 and 1980) and 2006 SPOT-5 satellite image of the Gerado catchment. Other, non-visual data were gathered from personal interview and focus group discussions conducted in 2010 and 2011 with local elders, farmers and development (agricultural extension) agents. The results identified the presence of cultivated and rural settlement land, shrubland, woodland, bare land, grassland, urban built up area and forest. Throughout the period 1958–2006, urban built-up area, forest and cultivated and rural settlement land expanded at an average rate of 6.85%, 1.85% and 0.14% per year at the expense of shrub, wood and grasslands, which declined by 0.77%, 0.21%, 0.65% per year, respectively. The land use/cover dynamics of 1958–2006 resulted in the reduction/loss of biodiversity, occurrence of high soil erosion and ramification of gullies. The triggers for these changes were population growth, land cultivation, expansion of farmland, inappropriate land management, civil war and fuel wood demand. These led to further land degradation and more food insecurity among many farming households. Land resources have to be used according to their suitability. Thus, the exposed and steep mountains of the area have to be protected from cultivation and should be re-afforested. The paper discusses other implications for management and policy formulation also.