Highlighting the effects of land-use change on a threatened amphibian in a human-dominated landscape

In Western Europe, habitat loss and landscape fragmentation has led to significant population decline in various animal groups, including amphibians. The extinction of the last natural populations of the yellow-bellied toad in Belgium, Luxembourg and several regions of southern and western France suggests a widespread decline. By using site-occupancy models and adding covariates corresponding to the human-influenced features of the landscape, we tried to identify the relative effects of different land-use types on the species’ distribution pattern in a man-made environment (the Alsatian Rhine floodplain in France). We recorded presence–absence data in 150 forest sample plots (300 × 300 m) and then modeled species distribution while taking into account detection errors in the field. Land-use was recorded on two spatial scales: within the forest sample plots and in a 1500 m radius buffer area around the forest plots. In the forest plots, toad occurrence was negatively correlated with loss of forest cover to agricultural land. In contrast, occurrence is positively correlated with the density of human-made rutted dirt paths and tracks, which provide semi-natural breeding sites. In the 1500 m radius buffer zones around forest plots, toad occurrence was negatively correlated with the density of urbanization and road networks. These results can be used to plan conservation strategies for amphibians in human-dominated landscapes.     

Agricultural land-use in China: a comparison of area estimates from ground-based census and satellite-borne remote sensing

We compare estimates of total cropland area, paddy rice area, and irrigated cropland area in China from land cover maps derived from optical remote sensing in 1992–93 (1-km resolution NOAA AVHRR) and county-level agricultural census data for 1990. At national, regional, provincial, and county scales, the total cropland area estimated by remote sensing is 50–100% higher than reported in the agricultural census. For topographically flat North and Central China, there is a high correlation between county-level cropland area estimates by the two approaches. For other regions, the correlation between remote sensing and agricultural census cropland area is much weaker. Throughout China, there is only moderate to weak correlation between remote sensing-based and census-bases estimates of paddy rice area and total irrigated cropland area. It is likely that the census data underestimates and the remote sensing overestimates the actual cropland area. These uncertainties in agricultural land cover estimates will contribute to uncertainty in any large-scale biogeochemical analyses.     

50 years of change in a Swedish boreal old-growth Picea abies forest

Abstract. Changes in the tree layer (> 1.3m) and sapling layer (< 1.3m, including seedlings) of a Swedish boreal old-growth Picea abies (Norway spruce) forest from the 1930s to the 1980s were studied in permanent plots. The plots were established in 1938–1939 and re-analysed in 1983–1988. Regeneration, mortality, turnover rate in the tree layer and amount of decomposing logs as well as the time required for complete decomposition of logs were investigated using the detailed data from the 1930s. Ca. 25 % of the trees present during the first analysis were no longer alive. This mortality was balanced by recruitment from the sapling layer. The rate of mortality suggests a turnover time for the tree layer of ca. 200 yr. The number of spruces in the sapling layer has increased by ca. 85 %, hypothetically in response to an increase in amount of decomposing wood that can serve as nurse logs and stumps. The mean time for total decomposition was calculated as ca. 200 yr. Spruce regeneration on logs does not occur until the log is at least ca. 50 yr old. The survival pattern in the sapling layer suggests a high mortality rate at the seedling stage (≤ 1 yr) and a low mortality rate at the sapling stage. In conclusion, it is suggested that the amount of coarse woody debris available for regeneration, the occurrence of seedlings, and seedling mortality constitute concurrent factors through which climatic fluctuations, in a long-term perspective, direct stand recruitment and density. As a consequence, these boreal forests will be kept in a dynamical equilibrium.     

典型喀斯特地区石漠化景观格局对土地利用变化的响应

土地利用是人类活动最基本的表现形式,探讨石漠化与土地利用变化之间的响应关系,对于石漠化治理和区域的可持续发展是非常重要的。基于贵州道真县2005年、2015年LANDSAT和石漠化数据,再利用ENVI 5.3进行监督分类,将道真县土地利用分为8种类型。通过景观格局空间分析技术和3S技术,对道真县土地利用时空演变和石漠化景观格局进行综合分析,结果表明:(1) 2005—2015年间,道真县建设用地和灌木林地面积增加,大部分灌木林地由水田和旱地转化而来,其面积增加了7.51%,建设用地增加了1.30%。(2)近10年间,研究区石漠化等级间的转移表现为轻、中、重度转化为潜在石漠化,其斑块转移面积分别为11.26、38.79、2.71 km2,表明研究区石漠化景观得到了恢复,低等级石漠化斑块面积增加,降低了原有高等级石漠化斑块的优势度。(3) 2005—2015年间道真县土地利用和石漠化景观格局,多样性指数分别下降了0.6434和2.4309,均匀度指数各减少了0.0552和0.5436,分维度指数各提高了0.0061和0.0801,蔓延度指数各增加0.1751、25.5396和聚合度指数分别增加1.8688和2.9112,景观形状指数分别减少0.9812和4.536,石漠化景观格局的变化对应土地利用景观格局指数的变化,随着人们土地利用方式的改变,石漠化也发生相应的改变。通过该研究的进行,有助于提高人们对石漠化和土地利用景观格局的认识,基于景观生态学背景对石漠化治理成效进行评估,为之后的石漠化治理工作的进行及研究提供了参考。     

Response of soil organic carbon to land-use change in central Brazil: a large-scale comparison of Ferralsols and Acrisols

Plant and Soil - The southeastern part of the Amazon region is one of the largest agricultural frontiers in the world, leading to extensive land-use change. This paper provides evidence for the...     

Conclusion: applying South East Asia Rainforest Research Programme science to land-use management policy and practice in a changing landscape and climate

The context and challenges relating to the remaining tropical rainforest are briefly reviewed and the roles which science can play in addressing questions are outlined. Key messages which articles in the special issue, mainly based on projects of the Royal Society South East Asia Rainforest Research Programme (SEARRP), have raised of relevance to policies on land use, land management and REDD+ are then considered. Results from the atmospheric science and hydrology papers, and some of the ecological ones, demonstrate the very high ecosystem service values of rainforest (compared with oil palm) in maintaining high biodiversity, good local air quality, reducing greenhouse emissions, and reducing landslide, flooding and sedimentation consequences of climate change-and hence provide science to underpin the protection of remaining forest, even if degraded and fragmented. Another group of articles test ways of restoring forest quality (in terms of biodiversity and carbon value) or maintaining as high biodiversity and ecological functioning levels as possible via intelligent design of forest zones and fragments within oil palm landscapes. Finally, factors that have helped to enhance the policy relevance of SEARRP projects and dissemination of their results to decision-makers are outlined.     

Two decades of change in the ground vegetation of a mixed deciduous forest in an agricultural landscape

Abstract. A vegetation survey of semi‐permanent plots was performed in 1977–1980 and in 1997–1998 to study the floristic changes in a mixed deciduous forest situated in a region of intensive livestock breeding. Our aim was to test the hypothesis of allogenic succession in the forest ground vegetation caused by the emissions of the surrounding agricultural activities. During the last 20 years, a significant increase of nitrogen indicators and a decline of moisture indicators were observed. Results were consistent at the community, the plot and the species level. Nitrogen deposition and the lowering of the groundwater table are suggested as the driving forces behind the changes. The results are discussed in the context of current ecological theory concerning resource competition and community diversity.     

Bluetongue: a historical and epidemiological perspective with the emphasis on South Africa

ABSTRACT: Bluetongue (BT) is a non-contagious, infectious, arthropod transmitted viral disease of domestic and wild ruminants that is caused by the bluetongue virus (BTV), the prototype member of the Orbivirus genus in the family Reoviridae. Bluetongue was first described in South Africa, where it has probably been endemic in wild ruminants since antiquity. Since its discovery BT has had a major impact on sheep breeders in the country and has therefore been a key focus of research at the Onderstepoort Veterinary Research Institute in Pretoria. Several key discoveries were made at this Institute, including the demonstration that the aetiological agent of BT was a dsRNA virus that is transmitted by Culicoides midges and that multiple BTV serotypes circulate in nature. It is currently recognized that BT is endemic throughout most of South Africa and 22 of the 26 known serotypes have been detected in the region. Multiple serotypes circulate each vector season with the occurrence of different serotypes depending largely on herd -immunity. Indigenous sheep breeds, cattle and wild ruminants are frequently infected but rarely demonstrate clinical signs, whereas improved European sheep breeds are most susceptible. The immunization of susceptible sheep remains the most effective and practical control measure against BT. In order to protect sheep against multiple circulating serotypes, three pentavalent attenuated vaccines have been developed. Despite the proven efficacy of these vaccines in protecting sheep against the disease, several disadvantages are associated with their use in the field.     

A comparison of the results following oromandibular reconstruction using a radial forearm flap with either radial bone or a reconstruction plate

Fifteen cases of oromandibular reconstruction using a radial osteocutaneous flap were compared with 16 in which the mandible was replaced with a reconstruction plate and a forearm flap was used for intraoral lining. All cases involved oral cancer; most had been irradiated. Nine survived in each group. Complications included one infected nonunion in addition to two bone exposures in the bone group, compared with three cases of plate exposure and two bone exposures in the plate group. Functional results were similar in both, but osteointegrated implants were possible only in the patients receiving bone. Cosmesis seemed somewhat better in the plate group. Donor-site problems were common but minor, and long-term forearm function was slightly reduced in both groups. Although the sample sizes were small, the reconstruction plate together with a radial forearm flap appeared to provide effective reconstruction following composite resection. However, we would not recommend this for the younger patient or in benign disease.     

The structure and function of the Golgi apparatus: a hundred years of questions

Over the last century, the Golgi apparatus has attracted the attention of researchers world-wide. This highly variable and polymorphic organelle plays a central role in intracellular membrane traffic. Not only does it receive all the secretory material and membrane synthesized by the endoplasmic reticulum and modifies these products by glycosylation, but also packages them and sends them in vesicular carriers to their correct destinations. It is also capable of the synthesis of complex polysaccharides used for building cell walls, a feature unique for higher plants. Yet, the current models of Golgi function are based on those established for yeast and mammalian cells and may not be completely relevant to plants. This review is an attempt to summarize the current knowledge of the plant Golgi apparatus and, where possible, to discuss the applicability of the current models of Golgi function to the plant cell.     

Two hundred years of a diverse Daphnia community in Lake Naivasha (Kenya): effects of natural and human-induced environmental changes

1. We used fossil diapausing eggs extracted from ²¹⁰Pb‐dated sediment cores to reconstruct historical changes in the Daphnia community of Lake Naivasha, a climate‐sensitive lake in Kenya which over the past 200 years has experienced a series of well‐documented natural and anthropogenic environmental changes. 2. Contiguous sampling and analysis of four cores yielded ephippial capsules of eight Daphnia species. Only two of these had been recorded previously in live collections from Lake Naivasha, and one species is new to science. The four more common species (Daphnia barbata, D. laevis, D. magna, and D. pulex) show striking differences in abundance patterns and population dynamics through time. Four other species (D. lumholtzi, D. curvirostris, D. longispina s.l., and Daphnia sp. nov. type Limuru.) appear to have been present only occasionally. Nevertheless, between 1895 and 1915 seven species of Daphnia inhabited Lake Naivasha simultaneously. 3. Despite considerable natural environmental change associated with climate‐driven lake‐level fluctuations, the Daphnia community of Lake Naivasha has been severely affected by human activities over the past century, especially the introduction of exotic fishes and water‐quality changes because of agricultural soil erosion. The recent reappearance of large‐bodied Daphnia species (D. magna, D. barbata, D. lumholtzi, Daphnia sp. nov. type Limuru) after 20–110 years of absence can be explained by their release from fish predation, following a dramatic increase in turbidity caused by excess clastic sediment input from eroded catchment soils. The small‐bodied species D. laevis has fared less well recently, presumably because the benefit of lowered predation pressure is counteracted by more pronounced negative effects of increased turbidity on this species and loss of submerged macrophyte beds which formerly served as predation refuge. 4. Our results suggest that, despite considerable environmental instability and the absence of specialised zooplanktivores, top‐down control of fish on large zooplankton is important in Lake Naivasha. Predation pressure from fish has led to clear‐cut shifts in local Daphnia species composition, but failed to drive the larger taxa to extinction.     

长白山风灾景观30年格局变化过程分析

以长白山自然保护区内的由1986年台风形成的风灾景观为研究对象。选取1987年、1993年、1999年、2004年、2010年和2016年遥感影像进行解译。利用Fragstats 4.2软件对景观格局指数进行定量分析,并用主成分分析法与景观综合评价指数相结合的方法对景观格局变化做出综合评价,揭示风灾后30年景观格局变化过程。结果表明：(1)草本-灌木的优势度不断下降;阔叶林和针叶林在恢复过程中先以增加大斑块为主,后期面积增加主要是以小斑块为主;岳桦林恢复过程中先以增加小斑块为主,后期以大斑块连片生长。(2)小而分散的斑块在恢复过程中转换为大而集中的斑块,景观趋于均质化。(3)草本-灌木,阔叶林,针叶林,岳桦林四种斑块类型在恢复过程中呈现一种演替关系。(4)确定了分别与景观规模、形状和景观聚散度相关的两个主成分,作为表征景观恢复性的关键指标。(5)在30年的恢复期中,研究区整体景观格局质量得到提升,但恢复缓慢,与风灾前依然相差较大。(6)多次强风干扰可以形成长白山西、南坡非标准的垂直带谱。     

Chlamydia trachomatis: milestones in clinical and microbiological diagnostics in the last hundred years: a review

Chlamydia trachomatis an obligate intracellular, Gram-negative bacterium is the causative agent of several acute or chronic, local and systemic human diseases such as trachoma, oculogenital and neonatal infections. It was discovered in 1907 by Halberstaedter and von Prowazek who observed it in conjunctival scrapings from an experimentally infected orangutan. In the last hundred years the detection and study of the intracellular pathogens, including chlamydiae, passed through an enormous evolution. This memorial review is dedicated to these important research and diagnostic discoveries and to the scientists who significantly contributed to this evolution starting from the application of simple light microscopy through the cell culture technique, antibiotic susceptibility, antigen and antibody detection, serotyping, to the real-time nucleic acid amplification and restriction fragment lengths polymorphism analysis. Although the majority of these old and new excellent diagnostic methods have been introduced into the rutine practice, the trachoma has remained one of the leading causes of blindness, and oculogenital chlamydial infections still are the most frequent sexually transmitted bacterial diseases, furthermore lymphogranuloma venereum is a disease emerging in the developed countries at the beginning of the 21 st century.     

Estimating the consequences of land-use changes on butterfly diversity in a marginal agricultural landscape in Sweden

Abandonment of farming with the resultant increase in forest cover is one of the major threats to semi-natural grasslands in marginal agricultural areas. In Sweden, the loss of semi-natural grassland is a serious nature conservation problem since it is one of the most species-rich habitats. In this study, the consequences of grassland abandonment and afforestation on butterfly diversity and butterfly dispersal costs are estimated and used to compare three different future land-use scenarios for a marginal agricultural landscape in Sweden. Based on previous butterfly surveys on grasslands in the area, a relationship between land-use type and butterfly diversity was established. By comparing land-use maps of different scenarios, the number of suitable habitat patches and total suitable habitat patch area with low, medium and high butterfly diversity could be estimated. To obtain an indication of possible fragmentation effects, a least-cost analysis was used to compare travel costs of the butterflies between suitable habitat patches for the different scenarios. The results show that different land-use scenarios affect butterfly diversity and travel costs differently. In the extreme case scenario of cessation of full-time farming and a reduction in part-time farming, nearly all valuable butterfly habitats will vanish, since the most species-rich habitats lie in the periphery of the settlement and are expected to be abandoned and afforested first. If, on the other hand, grassland management is less reduced the effect of abandonment on butterflies depends very much on which areas continue to be managed. To preserve the most important grasslands for butterflies an active management strategy for the whole study area would be needed. While it seems relatively easy to identify the areas most important to conserve from a butterfly diversity perspective, it will be more difficult to find an optimal spatial solution that also minimises dispersal costs for butterflies.     

Diel activity of Gammarus pulex (Crustacea) in a South Swedish stream: comparison of drift catches vs baited traps

The benthos of a perennially ice-covered Antarctic lake, Lake Hoare, contained three distinct signatures of lipophilic pigments. Cyanobacterial mats found in the moat at the periphery of the lake were dominated by the carotenoid myxoxanthophyll; carotenoids: chlorophyll a ratios in this high light environment ranged from 3 to 6.8. Chlorophyll c and fucoxanthin, pigments typical of golden-brown algae, were found at 10 to 20 m depths where the benthos is aerobic. Anaerobic benthic sediments at 20 to 30 m depths were characterized by a third pigment signature dominated by a carotenoid, tentatively identified as alloxanthin from planktonic cryptomonads, and by phaeophytin b from senescent green algae. Pigments were not found associated with alternating organic and sediment layers. As microzooplankton grazers are absent from this closed system and transformation rates are reduced at low temperatures, the benthos beneath the lake ice appears to contain a record of past phytoplankton blooms undergoing decay.     

Impact of landscape predictors on climate change modelling of species distributions: a case study with Eucalyptus fastigata in southern New South Wales,Australia

Aim We consider three questions. (1) How different are the predicted distribution maps when climate‐only and climate‐plus‐terrain models are developed from high‐resolution data? (2) What are the implications of differences between the models when predicting future distributions under climate change scenarios, particularly for climate‐only models at coarse resolution? (3) Does the use of high‐resolution data and climate‐plus‐terrain models predict an increase in the number of local refugia? Location South‐eastern New South Wales, Australia. Methods We developed two species distribution models for Eucalyptus fastigata under current climate conditions using generalized additive modelling. One used only climate variables as predictors (mean annual temperature, mean annual rainfall, mean summer rainfall); the other used both climate and landscape (June daily radiation, topographic position, lithology, nutrients) variables as predictors. Predictions of the distribution under current climate and climate change were then made for both models at a pixel resolution of 100 m. Results The model using climate and landscape variables as predictors explained a significantly greater proportion of the deviance than the climate‐only model. Inclusion of landscape variables resulted in the prediction of much larger areas of existing optimal habitat. An overlay of predicted future climate on the current climate space indicated that extrapolation of the statistical models was not occurring and models were therefore more robust. Under climate change, landscape‐defined refugia persisted in areas where the climate‐only model predicted major declines. In areas where expansion was predicted, the increase in optimal habitat was always greater with landscape predictors. Recognition of extensive optimal habitat conditions and potential refugia was dependent on the use of high‐resolution landscape data. Main conclusions Using only climate variables as predictors for assessing species responses to climate change ignores the accepted conceptual model of plant species distribution. Explicit statements justifying the selection of predictors based on ecological principles are needed. Models using only climate variables overestimate range reduction under climate change and fail to predict potential refugia. Fine‐scale‐resolution data are required to capture important climate/landscape interactions. Extrapolation of statistical models to regions in climate space outside the region where they were fitted is risky.     

One hundred years of American botany: a short history of the Botanical Society of America

This paper offers highlights from the 100 (plus) years of the Botanical Society of America (BSA) and draws extensively on the archives of the BSA. In addition to examining the founding of the society and the attempt to "professionalize" botany in late 19th century America, the paper also explores the complex relations between the BSA and a number of related societies in the United States, the Society's struggle to create a coherent identity for itself, the place of botany as a whole in the context of the burgeoning biological sciences in the 20th century, and the changing role of the BSA in an international context. The paper assesses both the achievements and the challenges facing the BSA. It closes by offering some historical reflections on the status of "botany" as a science and the historical significance of terms like "plant biology" and "plant science."