Measuring uncertainty in estimates of biodiversity loss: The example of biodiversity intactness variance

Developing adequate indicators of biodiversity change is an urgent task for biodiversity studies and policy. An important component of any indicator is a measure of the uncertainty in the estimates it produces. In this paper, we derive the biodiversity intactness variance (BIV) as a formal measure of uncertainty to accompany the recently developed biodiversity intactness index (BII) (Scholes and Biggs [Scholes, R.J., Biggs, R., 2005. A biodiversity intactness index. Nature 434, 45–49]). The BII is based on estimates of baseline species richness, the area of different land-uses, and the abundance of different species under different land uses. The BIV quantifies uncertainty in the abundance estimates, which are the main source of uncertainty in BII. The BII for southern Africa in the year 2000 has been estimated at 84.4%. We calculate the accompanying BIV at 50.4, providing a 95% confidence interval of 76.6–92.2% for BII. By applying the BIV, we can quantify the major sources of uncertainty in the BII for southern Africa: they stem from the abundance estimates for mammals and birds, and for savanna regions and degraded areas. The BIV therefore provides a means for better assessing the state of biodiversity loss and for highlighting research priorities.     

Modelling the efficacy of proposed mitigation areas for shorebirds: a case study on the Seine estuary, France

A behaviour-based model was used to explore the effect of an extension of the port at Le Havre (Port 2000), and the effect of proposed mitigation measures, on the mortality and body condition of the three main shorebird species that overwinter in the estuary of the river Seine, France. In the model, a 20% reduction in the area of mudflats on the north side of the estuary had little effect on curlew Numenius arquata mortality and body condition but significantly increased mortality and decreased body condition in dunlin Calidris alpina and oystercatchers Haematopus ostralegus. Disturbance of feeding birds both day and night had a significant effect on the mortality and body condition of all three shorebird species, as did disturbance of roosting birds. Disturbance of feeding birds in the daytime only had a significant effect on dunlin mortality and body condition, but not that of curlew and oystercatchers. In the model, the creation of a buffer zone to reduce disturbance of feeding birds restored shorebird mortality and body condition to pre-disturbance levels. A new mudflat area was also effective in mitigating the effect of habitat loss on all three shorebirds and in mitigating the effect of roost disturbance on dunlin and curlew. However, a new mudflat area was not effective in mitigating the effect of roost disturbance on oystercatcher mortality and body condition. The effectiveness of the mitigating mudflat depended as much on its size as its quality. We believe that this is the first time that anyone has been able to forecast the efficacy of proposed mitigation measures.     

The value of species rarity in biodiversity recreation: A birdwatching example

Wildlife viewing recreation offers conservationists opportunities for education and generating revenue but can also have detrimental ecological impacts. To manage these opportunities and impacts effectively, a better understanding is needed of what people value in wildlife viewing events. We examine the relationship between species rarity and value for wildlife viewing recreation. We undertook visitor counts of birdwatchers attending rare (vagrant) bird sightings and collected home postcodes to assess the distances these individuals travelled to achieve these sightings. We also undertook visitor counts at common bird viewing locations for comparison. We regressed birdwatcher numbers against rarity, site protection status, time the bird had been on site and day of the week when the count took place. We undertook these analyses for rare bird sightings only, using a continuous measure of rarity, and for both rare and common species combined, using a categorical rarity index. Species rarity was the clearest predictor of visitor numbers in both the analyses. When studying rare birds only, we found the functional form of the relationship between rarity and visitor numbers to be inverse and asymptotic. Individuals also travelled further to see rarer species. However, while exceptional numbers of visitors attended exceptionally rare bird sightings, the marginal value of rarity appeared to be relatively low. Despite the opportunity for revenue raising and education provided by rare bird sightings, a comparison of visitor numbers at sightings inside and outside protected areas showed no evidence that managers of protected areas capitalise on these opportunities.     

农田边界与生物多样性研究进展

本文综述了农田边界内涵和不同类型农田边界的特点及其生物多样性保护的关系,并依据对生物的保护功能和管理方法,可以把农田边界分成昆虫栖息地、保育边行、作物边界、休耕边界、无植被边界、开花植被边界及无作物野生生物边界。同时根据我国耕地资源和农田特点,提出研究农田边界生态学功能的必要性和进一步研究方向;即：边界生态系统与其生物多样性维持的关系,边界的植被结构与有害生物的关系,边界杂草种群和群落与节肢动物的关系,边界内生物的食物链关系,边界的管理措施。     

Metal uptake in maize, willows and poplars on impoldered and freshwater tidal marshes in the Scheldt estuary

Foliar Cd and Zn concentrations in Salix, Populus and Zea mays grown on freshwater tidal marshes were assessed. Soil metal concentrations were elevated, averaging 9.7 mg Cd kg^?1 dry soil, 1100 mg Zn kg^?1 dry soil and 152 mg Cr kg^?1 dry soil. Cd (1.1–13.7 mg kg^?1) and Zn (192–1140 mg kg^?1) concentrations in willows and poplars were markedly higher than in maize on impoldered tidal marshes (0.8–4.8 mg Cd kg^?1 and 155–255 mg Zn kg^?1). Foliar samples of maize were collected on 90 plots on alluvial and sediment‐derived soils with variable degree of soil pollution. For soil Cd concentrations exceeding 7 mg Cd kg^?1 dry soil, there was a 50% probability that maize leaf concentrations exceeded public health standards for animal fodder. It was shown that analysis of foliar samples of maize taken in August can be used to predict foliar metal concentrations at harvest. These findings can therefore contribute to anticipating potential hazards arising from maize cultivation on soils with elevated metal contents.     

Linking species richness, biodiversity and ecosystem function in soil systems

Soils are the central organizing entities in terrestrial ecosystems and possess extremely diverse prokaryotic and eukaryotic biota. They are physically and chemically complex, with micro- and macro-aggregates embedded within a solid, liquid and gaseous matrix that is continually changing in response to natural and human-induced perturbations. Recent advances in molecular techniques in systematics have provided opportunities for the study of biodiversity and biocomplexity of soil biota. A symposium and workshop on soil biogeochemistry and biodiversity International Symposium on Impacts of Soil Biodiversity on Biogeochemical Processes in Ecosystems, Taiwan Forestry Research Institute, Taipei, Taiwan April 18-24, 2004. Convened an international array of participants working in biomes on virtually every continent on the planet (ranging from polar to tropical regions). This special issue reports on the theoretical bases and applications of molecular methods for the measurement of soil biodiversity.

Themes addressed include a melding of classical taxonomic investigations with biochemical fingerprinting and molecular probing of organism identities. Several papers highlight new advances in identifications of prokaryotic and eukaryotic organisms. Examples include new developments in “fingerprinting” of microbes active in “mycorrhizospheres” using immunocapture and other innovative techniques. Developments in the study of impacts of invasive plant and animal species on ecosystem function and subsequent microbial community composition and function have been very great in the last 2-3 years. Soils are major repositories of legacies, including fine and coarse woody debris and other organic products, which have feedbacks on soil diversity. The ways in which species diversity and function of microbial and faunal communities interact and their importance to ecosystem function are examined in biological and biochemical detail. This paper provides an overview of soil biodiversity and its feedbacks on soil biogeochemical processes in ecosystems.     

Understanding mental constructs of biodiversity: Implications for biodiversity management and conservation

The participation of the public in environmental decision-making and management is increasingly seen as essential for the success of conservation initiatives. Ecological scientists and conservation practitioners have, however, argued that a lack of understanding of biodiversity issues by the public is a barrier to their effective participation in decision-making processes. These arguments are often based on studies where scientific knowledge is used as the sole measure of public understanding of biodiversity, and therefore fail to account for individuals’ constructs of biodiversity and related issues such as biodiversity management.We examined individuals’ mental constructs of biodiversity, and their conceptual contexts, through a series of focus group discussions with members of the general public in Scotland. To gain a fuller picture of public understanding of biodiversity, we distinguished between mental associations with the term ‘biodiversity’, and the meanings associated with biodiversity-related concepts independent of scientific terminology.We found participants to express rich mental concepts of biodiversity, irrespective of their scientific knowledge. These included notions of balance, food chains and human-nature interactions, and showed strong normative dimensions that were used to define desirable or ideal states of nature. These concepts of biodiversity were, in turn, strongly related to their attitudes towards how best to manage biodiversity.This study highlights that a better understanding of individuals’ mental constructs of biodiversity, which are linked to their attitudes towards biodiversity management, is essential for the design of biodiversity-related policies that are supported by the public.     

Impacts of different agricultural practices on the biodiversity of microarthropod communities in arable crop systems

Two crop production systems, which differ on tillage and pesticides, were compared for biodiversity of soil microarthropod communities. A biodiversity index, which integrates different structure and density parameters (abundance, taxonomic richness, taxonomic diversity, coenotic diversity) was used. Results showed a greater biodiversity in minimum tillage systems compared to deep tillage systems. Pesticides seemed to be only a second order factor of variance on microarthropod biodiversity.     

Induction of high affinity nitrate and ammonium uptake systems in wheat

Abstract

The ability of 7 day old wheat seedlings to take up nitrate or ammonium from hydroponic solution was measured. Seedlings were grown under fully aerated hydroponic conditions. The growth solution consisted of either 0.5 mM CaSO₄ alone or in combination with high nitrate (5 mM NO₃ ^‐ ), high ammonium (2 mM NH₄ ⁺) or modified 1/10 Hoaglands solution with nitrate N only (14 mM) or ammonium N only (2 mM). After washing the roots for one hour in CaSO₄, nitrate or ammonium uptake was measured with an ion selective electrode. Plants grown in high nitrate were unable to take up nitrate from a 0.1 mM external solution. Those grown in CaSO₄ were able to take up nitrate at the same external concentration (flux = 10.2 +/‐ 3.0 μmol nitrate/g dry wtlbh). The same result was seen for plants grown in high ammonium vs those grown in CaSO₄ (flux = 21.0 +/‐ 10.0 μmol/g dry wtlbh). Similar results were obtained when modified Hoagland's solution was substituted for the high N solutions. These data indicate that wheat roots possess both high and low affinity nitrate and ammonium uptake systems. The data further indicate that, for a given ion, the high and low affinity systems do not operate simultaneously under high N conditions. The high affinity system is switched off in the range of 1 mM for both ionic forms of N. Developmental studies show that the expression of the high affinity trait is reversible and may be induced (repressed) by conditioning for 24 h in low (high) N media. Plants grown in high N solutions showed efflux of the ion under assay conditions. Neither ion interfered with the induction/repression of the high affinity trait for the other under the conditions used in this study.     

农业系统中生物多样性利用的研究现状与未来思考

"现代农业"生产力高,但生物多样性简单化、生物之间的相互作用及其生态学效应常常被忽略,其生产力的稳定性主要依赖于化学肥料、农药、灌溉和高产品种等的投入。传统农业则是利用当地生物多样性(物种多样性和遗传多样性)和生物之间的相互作用来产出食物和维持系统的稳定。因而现代农业能否借鉴传统农业对生物多样性利用的经验,将工业化模式的现代农业转换为生物多样性利用与现代技术相结合的农业受到关注。本文分析了农业系统中生物多样性的特点及农业方式对农业生物多样性的影响;综述了农业系统中生物多样性利用模式与效应方面的研究进展;讨论了在现代农业系统中,利用生物多样性需要开展的研究,即区域上如何布局农业景观多样性,农田内如何根据生物之间的互惠关系配置物种多样性的种养体系,如何建设与生物多样性利用相应的田间设施和发展新型的农业机械、并建立以信息化为基础的管理体系。     

Triazines in the Marne and the Seine Rivers (France) Longitudinal Evolution and Flows

The transportation pathways of triazines were investigatedfrom their origins onwards, in the Marne and the Seine rivers(France). According to the 1991 survey, the highest total triazine concentration levels (956 ng L^-1) were found in the river Marne: 580 ng L^-1 for atrazine and 200 ng L^-1 for simazine, in relation with agricultural practices.The total triazine levels reached 829 ng L^-1 in the riverSeine. The other triazines remained low, from 5 to 75 ng L^-1. The triazine fluxes were 226 and 404 kg for a 118 d period in the Marne and the Seine rivers, respectively. Out of the treatment period, triazine peaks were related to riverflows with a 48 hr delay between the peak and the top of theflood. After herbicide treatment, peak concentrations wereclosely related with the precipitations. Concerning theriver Marne tributaries, highest atrazine concentrationswere found in June, in those which drained the vineyardarea. In January, the concentrations were higher inperiurban areas underlining their contribution to theherbicide inputs in the rivers. On the whole, the ratio oftriazines transported in the two rivers represented 0.2%of the total amount applicated annually on their catchment basins.     

Potassium uptake by Marianna plum under limited oxygen and elevated carbon dioxide levels in the root atmosphere

Potassium (K) uptake rates were determined for Marianna 2624 rootstocks with ‘French’ prune scions using the nutrient solution depletion technique. The nutrient solutions were bubbled with factorial combinations of nitrogen (N₂), oxygen (O₂), and carbon dioxide (CO₂) to create treatment root atmospheres with O₂ ranging from 0.01 to 0.10 m³/m³ and CO₂ ranging from 0 to 0.05 m³/m³. The K⁺ uptake rate was more susceptible to O₂ deprivation than to elevated CO₂ in the root atmosphere. Decreasing O₂ levels from 0.10 m³/m³ decreased K⁺ uptake in a hyperbolic fashion to no net uptake at 0.01 m³/m³ O₂. Increasing root atmosphere CO₂ from 0 to 0.05 m³/m³ had a small depressing effect on net K⁺ influx from 60 μM K⁺ solutions at 0.10 and 0.05 m³/m³ O₂, but no effect when O₂ was 0.025 or 0.01 m³/m³. Elevating CO₂ decreased Km for the net K⁺ influx rate at 0.10 and 0.05 m³/m³ O₂. Increased pH buffering from higher HCO₃ concentration at the plasma membrane surface was suggested to explain the CO₂ effect on Km.     

Influence of trees on soil organic matter in Mediterranean agroforestry systems: an example from the 'Espinal' of central Chile

The ‘Espinal’ agroforestry system of the Mediterranean zone of central Chile, which covers an area of 2000 000 ha, is in various stages of degradation due to human activities. The objective of our study was: (i) to determine the effects of the canopy cover of Acacia caven (‘Espino’) on total soil organic carbon (SOC), soil respiration and the labile components of soil organic matter (microbial biomass, and light fraction); and (ii) to determine the influence of ecosystem degradation on total and labile components of SOC. Soils of the study area are classified as fine, mixed, active, mesic Ultic Palexeralfs, typical of the Mediterranean‐type environment. We investigated sites according to the percentage coverage of A. caven canopy: (i) well‐preserved Espinal (WPE), 80–51% cover; (ii) good Espinal (GE), 50–26% cover; (iii) degraded Espinal (DE), 25–11% cover; and (iv) very degraded Espinal (VDE), < 10% cover. In addition, a site under native forest (NF) was included to characterize the original state of the zone. Soil samples were taken under and outside the canopy of A. caven at two depths, 0–5 and 5–10 cm. We conclude that the microbial biomass carbon (C_mic), and total and labile components of SOC are influenced by the presence of the A. caven tree, with greater values under than outside its canopy. Under the tree canopy, to a depth of 10 cm, C_mic was less under all the agroforestry systems than in NF (46 and 30% less for WPE and GE, respectively, and 67 and 57% less for DE and VDE). However, there was no clear trend for less C_mic with increased ecosystem degradation, especially outside the canopy. However, the respiration of microbial communities was affected by ecosystem degradation for both soil depths under the tree canopy, e.g. soil respiration in VDE ecosystems was about 50% greater than that found in WPE ecosystems. Increasing the coverage of the A. caven tree in the semiarid ecosystems of central Chile, e.g. changing from VDE to WPE, would result in an eventual, long‐term (over several centuries) increase in soil organic C of approximately 50%.     

Soil biodiversity monitoring in Europe: ongoing activities and challenges

The increasing interest in soil biodiversity and its protection includes both the biodiversity conservation issues and the mostly unknown economic and ecological values of services provided by soil biodiversity. Inventory and monitoring are necessary tools for the achievement of an adequate level of knowledge regarding soil biodiversity status and for the detection of biodiversity hot spots as well as areas where current levels of biodiversity are under threat of decline. In this paper the main tools and methodological approaches for soil biodiversity measurement are presented. Technical aspects related to the inventory and monitoring activities at a large spatial scale are discussed. A short review of some current experiences of soil biodiversity monitoring at the European level is also presented.     

Just passing through: Global change and the conservation of biodiversity in protected areas

Climate and land-use changes are expected to cause many species to shift into or beyond the boundaries of protected areas, leading to large turnover in species composition. Here, we tested whether long-established protected areas in Canada were more robust to such climate change impacts than areas with no formal protection by measuring changes in modeled butterfly species distributions (n = 139) within them. We used a recently established distribution modeling technique, Maxent, to model butterfly species’ distributions in two epochs (1900-1930 and 1960-1990). We compared rates of butterfly species richness and composition change within protected areas against distributions of randomly selected, ecologically similar, but non-protected, areas. Change in species richness and composition within protected areas were, for the most part, the same as changes observed among random areas outside protected area boundaries. These results suggest that existing protected area networks in Canada have provided little buffer against the impacts of climate change on butterfly species richness, possibly because land-use change surrounding long-standing protected areas has not been substantial enough to elevate the habitat protection afforded by these protected areas relative to other areas. Although protected areas are unarguably beneficial in conserving biological diversity, their capacity to maintain habitat appears insufficient to prevent broader-scale climate changes from sweeping species beyond their boundaries.     

广东恩平市稻区越冬期不同土地利用方式下主要节肢动物多样性调查分析

连续两年对恩平市境内12个镇双季稻田越冬期的冬闲田、犁冬晒白田、冬种蔬菜、冬种马铃薯和冬闲田田埂等5种典型土地利用方式下各生境的主要节肢动物群落进行动态调查。结果表明：5类样地越冬期的主要节肢动物均以蜘蛛为主要优势种类,而鳞翅目（成虫）则成为冬种蔬菜的优势类群,5类样地的生物多样性指标均有显著差异（P〈0．05）,2005～2006年度越冬期的冬种蔬菜样地、冬种马铃薯样地的物种丰富度、均匀度和密度一类群指数均显著高于其他生境;冬种蔬菜以及冬闲田的Shannon-Wiener多样性指数（H）值较高,分别为1．8659&#177;0．1037和1．5909&#177;0．0938,而密度一类群指数（DG）则以蔬菜样地最大（7．5950&#177;0．0476）。2006～2007年度越冬期与上一年度调查结果基本相同,其中蔬菜样地与田埂的日值较高,分别为1．7825&#177;0．1454、1．1379&#177;0．1015,冬种蔬菜的DG值最大,为11．2103&#177;0．3512,表明冬种蔬菜对DG值有一定的促进作用,冬闲田与冬种马铃薯的Sorenson相似性系数（S1）最高,而犁冬田、田埂的S,则相对较低;犁冬田与冬种马铃薯田的Whittaker相似性系数（S2）最高,经作田与冬种马铃薯田的相似性系数S：则最低。结果表明犁冬田的各生物多样性明显差异于冬种田,冬种蔬菜对提高稻区生物多样性有重大作用。     

Effect of oxygen deficiency on uptake of water and mineral nutrients by tomato plants in soilless culture

The consequences of oxygen deficiency on the root system of tomato plants in soilless culture at the beginning of the flowering stage were assessed over a 72‐hour period. The study of water uptake and oxygen depletion in the medium was conducted using a process of continuous computerized data processing. Fluctuations in composition of the nutrient solution were monitored every two hours through an analysis of samples. Oxygen deficiency of the nutrient solution had immediate effects on the water and nutrient uptake of the whole plant. The root asphyxia of a tomato plant caused a 20 to 30% decrease of water uptake after 48 hours. After 10 hours it also leads to the end of the uptake process of the nutrients except nitrates. Potassium (K) was the nutrient most sensitive to oxygen deprivation since an efflux into the culture medium was observed after only 4 hours of deprivation. Nitrate uptake was the least affected by oxygen deficiency. The persistent appearance of nitrite in the culture medium 12 hours after the beginning of the asphyxia process could be caused by the reduction of nitrates by the root system of the tomato plant. The plant would use the oxygen from the reduction reaction to ensure the water and nitrate uptake processes which are the two most important limiting factors of plant nutrition. Thus it seems that under root asphyxia conditions the plant would adapt to the new condition by relying on a metabolism of the “nitrate respiration”; type.