Shrub‐based plantings of woody perennial vegetation in temperate Australian agricultural landscapes: What benefits for native biodiversity?

Summary  In the highly fragmented agricultural landscapes of temperate southern Australia, fodder shrubs are being established as part of commercial grazing enterprises to fill the summer-autumn livestock feed gap. These woody perennial plantings have greater structural complexity than conventional grazing systems and may supplement resources for native fauna. However, to date the resources provided by these systems are poorly defined or documented. In this paper, we identify the potential environmental values of fodder shrub plantings by considering natural and planted shrub-based systems, with a particular focus on planted saltbush in non-saline lands. In marginal agricultural areas, shrub-based perennial fodder crops can not only provide economic benefits through improved livestock productivity, but also contribute to reducing soil erosion and offer potential carbon sequestration opportunities. We contend that these systems may also provide resources for a range of native fauna. More information is needed on the biodiversity value of grazing systems based on perennial shrubs so that their potential to contribute to conservation in multifunctional landscapes can be fully realised and appropriate management recommendations provided.     

Small things are important: the value of singular point elements for birds in agricultural landscapes

Farmland birds belong to the most endangered group of vertebrates in Europe. They are an important component of farmland biodiversity considering the numerous functions they perform (e.g. seed dispersal, improving germination, increasing gene flow, nutrient recycling, and pest control). Therefore, their decline imposes substantial risks on agricultural ecosystems. In general, farmland bird conservation includes land-use and management alterations leading to less-intensive farming and land-sparing for breeding habitats (e.g. agri-environment-climate schemes, and organic farming). However, theoretical concepts describing farmland biodiversity maintenance and applied conservation measures usually ignore the role of singular, often very small, natural or man-made elements in an agricultural landscape. These elements play a role in the populations of certain species, their biology and in the general species richness of farmland. Furthermore, the importance of these elements has never been empirically tested, which means that conservationists and practitioners are not aware of their measurable value for birds. Herein, we define and identify singular point elements in the agricultural landscape (SPELs) which are potentially important for breeding farmland birds. We also describe each SPEL and evaluate its importance for birds in farmland based on a systematic review of the available literature. Using a horizon-scanning technique, we then polled field ornithologists about their personal observations of birds in relation to SPELs and the evaluation of the potential roles of such structures for birds. We identified 17 SPELs that vary in naturalness and age: singular trees, singular shrubs, erratic boulders, puddles, electricity pylons, wind turbines, spiritual sites, hunting platforms, fence and border posts, wells, road signs, scarecrows, piles of manure, piles of brushwood/branches, piles of stones/debris, piles of lime, and haystacks. Analysis of the literature revealed knowledge gaps, because some SPELs are frequently mentioned in ecological studies (e.g. trees, shrubs, pylons), but others such as spiritual sites, stones, hunting platforms, wells, road signs, or piles of lime are ignored. Despite the fact that some authors incorporate the effects of some SPELs in their studies, little research to date has aimed to assess the impact of various SPELs on farmland bird species numbers and distribution. Horizon scanning revealed that ornithologists often observe birds on various SPELs and thus, attribute to SPELs many functions that are important for maintaining bird populations. Horizon scanning also highlighted the importance of SPELs for many declining bird species and suggested possible mitigation of negative changes in the agricultural landscape by retaining SPELs within fields. We suggest that a better understanding of the role of SPELs for farmland birds is required. We also recommend that SPELs are considered as a potential tool for the conservation of birds, and existing conservation programs such as agri-environment-climate schemes and organic farming should be updated accordingly. Finally, we suggest that SPELs are included in predictive models that evaluate habitat suitability for farmland biodiversity.     

A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in‐field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in‐field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.     

High value of short rotation coppice plantations for phytodiversity in rural landscapes

The demand for wood from short rotation coppice (SRC) plantations as a renewable energy source is currently increasing and could affect biodiversity in agricultural areas. The objective was to evaluate the contribution of SRC plantations to phytodiversity in agricultural landscapes assessed as species richness, species–area relationships, Shannon indices, detrended correspondence analysis on species composition, Sørensen similarities, habitat preference proportions, and species proportions found in only one land use. Vegetation surveys were conducted on 12 willow (Salix spp.) and three poplar (Populus spp.) coppice sites as well as on surrounding arable lands, grasslands and forests in central Sweden and northern Germany. SRC plantations were richer in plant species (mean: 30 species per 100 m²) than arable land (10), coniferous forests (13) and mixed forests in Germany (12). Comparing SRC plantations with other land uses, we found lowest similarities in species composition with arable lands, coniferous forests and German mixed forests and highest similarities with marginal grassland strips, grasslands and Swedish mixed forests. Similarity depended on the SRC tree cover: at increased tree cover, SRC plantations became less similar to grasslands but more similar to forests. The SRC plantations were composed of a mixture of grassland (33%), ruderal (24%) and woodland (15%) species. Species abundance in SRC plantations was more heterogeneous than in arable lands. We conclude that SRC plantations form novel habitats leading to different plant species composition compared to conventional land uses. Their landscape‐scale value for phytodiversity changes depending on harvest cycles and over time. As a structural landscape element, SRC plantations contribute positively to phytodiversity in rural areas, especially in land use mosaics where these plantations are admixed to other land uses with dissimilar plant species composition such as arable land, coniferous forest and, at the German sites, also mixed forest.     

Elevational gradients in species abundance,assemblage structure and energy use of rainforest birds in the Australian Wet Tropics bioregion

Elevational patterns of species richness, local abundance and assemblage structure of rainforest birds of north‐eastern Australia were explored using data from extensive standardized surveys throughout the region. Eighty‐two species of birds were recorded with strong turnover in assemblage structure across the elevational gradient and high levels of regional endemism in the uplands. Both species richness and bird abundance exhibited a humped‐shaped pattern with elevation with the highest values being between 600 and 800 m elevation. While much of the variability in species richness could be explained by the species–area relationship, analyses of net primary productivity (NPP) and total daily energy consumption of the bird community (energy use) suggest that ecosystem energy flow or constraints may be a significant determinant of species richness. Species richness is positively correlated with local bird abundance which itself is closely related to total energy use of the bird community. We suggest the hypothesis that lower NPP limits bird abundance and energy use in the uplands (>500 m) and that low bird energy use and species richness in the lowlands is limited by a seasonal bottleneck in available primary productivity and/or a species pool previously truncated by an extinction filter imposed by the almost complete disappearance of rainforest in the lowlands during the glacial maxima. We suggest that some of the previously predicted impacts of global warming on biodiversity in the uplands may be partially ameliorated by increases in NPP because of increasing temperatures. However, these relationships are complex and require further data specifically in regard to direct estimates of primary productivity and detailed estimates of energy flow within the assemblage.     

Effects of soil salt levels on the growth and water use efficiency of Atriplex canescens (Chenopodiaceae) varieties in drying soil

The effect of salt stress on the growth and water use efficiency of the xerohalophyte Atriplex canescens (Pursh.) Nutt. in drying soil was determined by growing plants to the wilting point in soils receiving a one-time irrigation of nutrient solution containing low, medium, and high levels of NaCl. The experiment compared three varieties of A. canescens that differed in salt tolerance and capacity for Na and K uptake in previous research. Contrary to expectations, we did not find that water and salt stress were strictly additive in reducing plant performance. Soil salts enhanced the growth performance of the plants in drying soil by increasing their days to wilting, ability to extract water from the soil, organic matter production, and water use efficiency. The variety with the highest salt tolerance also had the highest growth rates and water use efficiency on drying soils. We conclude that tolerances to water and salt stress are linked through a common mechanism of Na uptake for osmotic adjustment in this species.     

Revegetation,restoration and reptiles in rural landscapes: Insights from long‐term monitoring programmes in the temperate eucalypt woodlands of south‐eastern Australia

Over the past decade, there has been a concerted effort to better understand the distribution and abundance of reptiles in agricultural landscapes and to specifically evaluate their response to revegetation (tree and shrub plantings) and habitat restoration in the wheat‐sheep belt of south‐eastern Australia. This article reviews the response of reptiles to revegetation and woodland management and provides ten insights and lessons that can be applied to help improve reptile conservation in temperate eucalypt woodlands and fragmented agricultural landscapes in Australia. The review focuses primarily on revegetation programmes conducted by Landcare and Greening Australia, and management interventions funded by Local Land Services in NSW and Catchment Management Authorities in Victoria.     

Phylogeography of a game species: the red-crested pochard (Netta rufina) and consequences for its management

Western European populations of red-crested pochard (Netta rufina) are characterized by low size and high fragmentation, which accentuate their sensitivity to hunting. Uncertainties regarding the demographic trends of these populations highlight the need for pertinent hunting regulations. This requires identification of the limits of the populations under exploitation, i.e. delimiting a management unit. We used the left domain of the mitochondrial control region and seven nuclear loci (four microsatellites and three introns) to assess the level of genetic structure and demographic independence between the fragmented Western European and the large Central Asian populations. The second objective was to investigate the colonization history of the Western European populations. This study demonstrated that the Western European populations of red-crested pochard constitute a separate demographic conservation unit relative to the Asian population as a result of very low female dispersal (mitochondrial DNA: PhiST = 0.152). A morphometric analysis further suggested that Central Asian and Western European specimens of both sexes originate from different pools of individuals. Male dispersal seems higher than female dispersal, as suggested by the lack of clear genetic structure for the nuclear markers at this continental scale. Genetic data, in conjunction with historical demographic data, indicate that the current Western European populations probably originate from a recent colonization from Central Asia. As numbers of red-crested pochards in Western Europe cannot be efficiently supplemented by immigration from the larger Asian populations, a management plan regulating the harvest in Western Europe is required.     

新疆北部棉区作物景观多样性对棉铃虫种群的影响

如何从景观尺度上实现对害虫的科学管理已经成为昆虫生态学的研究热点.利用频振式杀虫灯诱集技术,从2007-2009年在新疆北部棉区16-17个农场近240km2作物范围内,监测和评估棉田周边作物景观对棉铃虫种群的影响.结果表明:农业景观多样化显著地影响棉铃虫种群数量,复杂作物系统中(棉花比例＜50％作物面积)棉铃虫成虫数量明显大于简单作物系统(棉花比例≥50％作物面积;棉铃虫种群数量与景观多样性指数(Simpson's Reciprocal Index)呈正相关;同时棉铃虫成虫与加工番茄、玉米和小麦的比例成正相关,但与棉花比例呈负相关.研究结果为转基因棉花抗性管理提供科学依据,同时农田景观多样性指标可作为修正棉区棉铃虫预测模型的重要指标.     

Determining high value areas for steppe birds in Spain: hot spots,complementarity and the efficiency of protected areas

We have examined the distribution of 26 species of steppe birds in the Iberian Peninsula and the Balearic Islands within a grid of 5,070 10 × 10 km grid cells. The most valuable areas for steppe birds have been identified by selecting the upper 5% of the 10 × 10 km grid cells after a simple ranking based on the following criteria: species-richness, richness of rare species, rarity index, species vulnerability at Spanish, European and Global levels, and using an index combining the previous criteria. We have also used a heuristic algorithm to select those areas which offered most complementarity. The results have been analysed on a national scale and have been compared with those obtained by species assessments in previous status summaries. Finally, we have performed an analysis of the coverage afforded to locations which are valuable for steppe species by Natural Protected Areas (NPAs) and Special Protected Areas (SPAs), and an evaluation of the potential effects of temporal changes in species’ threat-status. The combined index was the most reliable criterion for defining hotspots, encompassing 15% of the species’ distributions within 5% of the total area considered. This index showed a high level of geographical concordance with the other criteria (nearly 70% of the selected grid cells coincided). Analysis of complementarity delivered poorer results than simple rank-scoring. The analysis of the efficiency of NPA network showed a very low coverage (less than 2%) of the hotspots selected according to the Combined Index. Coverage of the SPA network was higher (nearly 45%), although it diminished (to <35%) when only steppe-defined SPAs were included. The geographical concordance between high-value areas selected using current status summaries and those chosen using earlier ones was low for European threat status (53.4%), intermediate (63.2%) for Spanish threat status and high for SPEC status (78.1%). The Combined Index showed a high level of geographical concordance between the old and new data (76.6%). We conclude that automatic scoring methods (identifying hotspots) are useful for selecting valuable areas and for analysing the efficiency of the network of protected natural spaces, as well as for examining the potential effects of status changes on hotspot definition. Furthermore, the Spanish SPA network does not cover the most important areas for steppe birds adequately.     

Establishing the evidence base for maintaining biodiversity and ecosystem function in the oil palm landscapes of South East Asia

The conversion of natural forest to oil palm plantation is a major current threat to the conservation of biodiversity in South East Asia. Most animal taxa decrease in both species richness and abundance on conversion of forest to oil palm, and there is usually a severe loss of forest species. The extent of loss varies significantly across both different taxa and different microhabitats within the oil palm habitat. The principal driver of this loss in diversity is probably the biological and physical simplification of the habitat, but there is little direct evidence for this. The conservation of forest species requires the preservation of large reserves of intact forest, but we must not lose sight of the importance of conserving biodiversity and ecosystem processes within the oil palm habitat itself. We urgently need to carry out research that will establish whether maintaining diversity supports economically and ecologically important processes. There is some evidence that both landscape and local complexity can have positive impacts on biodiversity in the oil palm habitat. By intelligent manipulation of habitat complexity, it could be possible to enhance not only the number of species that can live in oil palm plantations but also their contribution to the healthy functioning of this exceptionally important and widespread landscape.     

1976-2013年三江平原景观生态风险变化及驱动力

受自然过程和人类活动的影响,三江平原景观生态风险格局发生了明显变化。采用GIS和RS技术构建景观风险指数,结合网格分析法和地理探测器分析1976-2013年三江平原景观生态风险变化及驱动力。结果表明,从时间上看,1976-2013年三江平原农田、草地和湿地的景观损失度逐渐降低,林地和居民用地景观损失度不断升高,生态风险呈逐渐降低趋势;从空间上看,1976年以高风险区为主,2013年则以低风险区为主,1976-2013年低风险、较低风险和中风险区不断向三江平原西部和西南部扩张,高风险和较高风险区逐渐向北部的黑龙江和乌苏里江沿岸及保护区退缩,生态风险整体向西南方向运移,风险质心向西南转移37.8 km;三江平原景观生态风险格局变化受海拔、地貌、居民点、保护区距离和人为干扰度影响明显,其中人为干扰度、居民点以及保护区距离对景观生态风险解释力最为显著,1995年人为干扰度（71.2%）、居民点距离（64.6%）和保护区距离（43.7%）的因子解释力明显高于地貌类型（11.2%）和流域类型（8.9%）,2013年地貌类型（23.5%）解释力大于保护区距离（23.3%）。该研究为湿地保护和恢复提供科学参考。     

Aquatic birds as bioindicators of trophic changes and ecosystem deterioration in the Mar Menor lagoon (SE Spain)

The Mar Menor is the largest coastal lagoon in the Western Mediterranean and it is an important site for wintering and breeding waterfowl. During recent decades several hydrological and land-use changes in the watershed have increasingly threatened the conservation of the lagoon due to the development of urban areas, tourism and agriculture. A dynamic system model has been developed at the watershed scale to estimate the annual load of nutrients reaching the Mar Menor-associated wetlands. At present, mean annual loadings of approximately 2000 tonnes of nitrogen and 60 tonnes of phosphorus are delivered to the lagoon. The simulation results emphasize the role of heavy rainfall events and floods in the formation of the total nutrient load. The composition of aquatic bird communities has been used to assess the nutrient impact on the lagoon food-web. The Great Crested Grebe is apparently the species most closely dependant on local trophic conditions. The related Black-necked Grebe, that dominates the waterbird community of the lagoon, plays a similar role, but its more opportunistic response to changes in food resources, reduces its indicator value. The abundance of the two species of grebes seems to closely track the nitrogen load curve, especially during the first phase of enrichment, suggesting the existence of a direct trophic relationship. In the following phase, jellyfish blooms coincide with the bird decline. Jellyfishes seem to have a buffering effect towards nutrients, determining a bottom up limitation to other trophic compartments. In recent years, this buffering capacity has probably been overloaded, favouring the growth of new food resources available to the grebes. Unlike grebes, Mergus serrator, a typical piscivorous bird, does not seem to be affected positively by eutrophication since it shows a long-term stability in numbers or even a slight decline. Since this suspected decline would parallel a long-term reduction of fish catches, the species could be regarded as a potential indicator of habitat deterioration.     

长江流域农作物起源及其与生物多样性特征的关联

长江流域的农耕文明是中华文明的重要组成部分。作为世界著名的农作物起源中心之一, 长江流域拥有丰富的生物多样性, 孕育了大量的栽培植物。本文梳理了起源于长江流域的农作物的资料以及新石器时代文化遗址的植物遗存信息; 结合对长江流域的自然环境特征与全新世以来植被变化的总结, 尝试厘清长江流域对植物资源利用的动态变化, 探讨本地栽培植物与生物多样性的关联。结果表明长江流域农耕文明以稻作为最主要的生产方式, 驯化了大量果树与水生蔬菜, 反映出对本地亚热带常绿阔叶林与湿地的依赖与适应。与其他流域相比, 长江流域具有相对优越的生态要素配置, 其驯化作物类型表现出典型的亚热带湿润森林植被区特征。研究长江流域农作物驯化相关的自然与人类因素, 有助于我们更好地把握长江流域农耕文明的起源。本文不但可为长江流域植物遗传资源的保护与开发提供参考, 而且对于推进长江流域的生态文明建设和可持续发展具有指导作用。     

Attributes of trees used by nesting and foraging woodpeckers (Aves: Picidae) in an area with old pollarded Oaks (Quercus spp.) in the Taurus Mountains,Turkey

We used three woodpecker species as umbrella species for old deciduous forests, and analysed their preferences in an area with old pollarded oaks in the Taurus Mountains, Turkey. Using plot inventories, we physically characterised trees utilised for nesting and foraging amongst woodpeckers in general and the Middle Spotted Woodpecker (Leiopicus medius) in particular. Trees more frequently visited by foraging woodpeckers differed from randomly chosen trees by being taller, having a larger circumference, greater bark furrow depth and shorter distance to neighbouring trees. Nesting trees were taller, had a higher proportion of dead wood but a lower surface area of natural cavities. Our results suggest that the woodpeckers in the study area rely upon woodlands containing mature trees, thus have the potential to function as suitable umbrella species’ to highlight the conservation value of oak forest habitats in southern Turkey.     

Factors affecting mortality of the scallop Chlamys asperrima (Lamarck) and its epizooic sponges in South Australian waters

This paper examines the effects of epizooic sponge cover, scallop size, and height of byssal attachment above sea-bed level on the survival of the scallop Chlamys asperrima (Lamarck) and its epizooic sponges. The presence of a sponge on a scallop increased survival in the field and in caging experiments. Mortality of small scallops was greater than that of larger ones, but small sponge-covered scallops suffered less predation than large bare ones. Attachment at the sea-bed level adversely affected both scallops and sponges. Scallops were more susceptible to starfish predation at sea-bed level, while sponges experienced more siltation and abrasion. Potential benefits of a mutualism are discussed.     

Native plantations as an important element for biodiversity in vanishing forested landscapes: A study of the near threatened araucaria tit spinetail (Leptasthenura setaria,Furnariidae)

Although forest loss is still a problem worldwide, estimated rates of deforestation have declined in the last decade, primarily because of an increase in the area of tree plantations. This leads to the central question of how suitable plantations are for indigenous species. Native plantations are thought to have higher value for biodiversity than plantations of non‐native trees; however, not all studies support this view. We assessed occupancy and density of the araucaria tit spinetail (Leptasthenura setaria, Furnariidae), a near threatened species, in the highly endangered araucaria forests of north‐eastern Argentina and in araucaria plantations, which comprise 90% of the remaining habitat for this species. All natural forest remnants were occupied by araucaria tit spinetails. Only 85% of the plantations were occupied; however, density was almost threefold higher in plantations compared with natural forests. Our models indicated that stand age was the most important factor in determining occupancy and density of this bird species in plantations. Plantations <10 years old exhibited lower densities than older plantations. This species does not occur in plantations of non‐native trees, but our results indicate that native plantations may provide important habitat for the araucaria tit spinetail, particularly given that most native forest has been removed. Restoration of natural remnants and conservation of old, connected plantations may assure the protection of significant populations of spinetails. The role of native araucaria plantations as habitat for other species merits further examination.