Biodiversity and Endangered Species: Issues of Significance

Assessing the vulnerability of Thailand's forest birds to global change

Biodiversity monitoring schemes are designed to infer trends in biodiversity over long time periods. The value of a biodiversity monitoring program depends largely on its data quality. High quality data allow to estimate temporal trends without bias and with high precision. Data quality largely depends on the initial design of the monitoring scheme, on properly conducted fieldwork, on various aspects of quality control mechanisms, and on the methods to analyse the data. In my thesis I show and discuss implications of design and data quality presenting five case studies using data from the Swiss Biodiversity Monitoring Scheme (BDM). The BDM is a long-term programme of the Swiss Federal Office for the Environment and was initiated in 2001 to monitor Switzerland’s biodiversity. The programme focuses on changes in species richness and surveys selected species groups in a systematic sampling grid all over the country. Defined and constant sampling methods are needed to allow for unbiased and precise estimations of biodiversity trends. In Chapter I, we analysed inter-observer variation of double-sampled vegetation plots. We could show that both systematic (directed) methodological errors and random variance of species counts were small. We concluded that BDM methods are adequate for detecting biodiversity trends. In the meantime this conclusion has been widely confirmed with recent data from quality control. Chapter II focuses on detectability of species that provides the link between a raw species count and true species richness. Variation in detectability between species or habitats may considerably bias trend estimates in biological studies. We therefore asked if capture-recapture methods were suitable to analyse differences in species detectability of butterflies and looked for underlying factors that may cause variation in detectability. Because the methods available at that time were not allowing the analysis of butterfly surveys over the whole season we had to restrict it to three mid-season surveys. We found that average detectability per count was 0.61 and was influenced by observer, transect and region. Individual species during one count were detected with a mean probability of 0.50. Since the study has been published in 2007 statistical methods have been substantially developed and nowadays enable detailed analyses of butterfly communities. In the study in Chapter III we demonstrated how data from the systematic BDM surveys could be used in combination with environmental variables. We tested different sets of variables for modelling plant species richness and produced species richness maps for Switzerland by predicting species richness for each kilometre square. We found that the final models performed similarly well. Average elevation was the best single variable for explaining plant species richness nationwide. Species richness maps typically showed belt-like patterns of highest richness at intermediate altitudes. We discussed different approaches for explaining such “mid-elevational peaks” of species richness. In the frame of the BDM vascular plants, butterflies and birds are surveyed on the same sites during the same years. These simultaneous studies may be considered as a major advantage of the BDM compared to the monitoring programs in other countries. In the final two chapters we therefore inferred patterns between the species groups. Chapter IV is based on data of the first iteration of surveys. We looked at the changes that had happened in surveyed species communities of plants, birds and butterflies within the period of 5 years. As a response to climate warming we expected species to shift their distribution towards higher altitudes. We used the “Community Temperature Index” (CTI) to test for differences in reaction to climate change. As expected, in the lowlands birds and butterflies tracked climate warming with an average uphill shift of 42 and 38m respectively, while plants showed a shift of only 8m. At higher elevations there was no significant CTI change in plants and butterflies. In general our results supported the idea that reactions to climate change in alpine landscapes were lowest and alpine landscapes could be safer places because of their highly varied surfaces. In the study in Chapter V we examined to what extent distribution patterns of butterfly species are shaped by interactions with their individual host plants or, alternatively, by environmental factors. Our findings indicated that butterfly - host plant interactions were not relevant in benign environments. In contrast, at the cold distribution limits there was a strong coincidence between butterfly and plant ranges. We argued that this could be evidence for butterfly species being limited by the distribution of their host plants in harsh environments and discussed the implications of the findings under climate change conditions. Finally I summarized the most important results and also included more recent experiences from other studies using BDM data and from unpublished analyses, e.g. from quality control. I concluded in discussing the strength and weaknesses of long-monitoring programmes and pointed out that they should be considered as a complementary data source and reference for experimentally orientated research.

Freshwater ecosystems represent hotspots for the world’s total diversity and human well-being. However, they are also subjected to threats across the globe as a result of localised human activities, broad scale catchment clearance, climate change and invasive species. The increased degradation of freshwater habitats and their ecological functions as a consequence of these threats, at local and global scales, has led to significant freshwater problems for human existence and the world’s biodiversity. There is growing evidence that the loss of biodiversity is one of the most complex environmental issues facing the world; however, the importance of understanding species distribution patterns and the ecological differentiation among species that are reflected as species-specific responses or tolerances to environmental drivers is less well understood. In particular, when a morphological approach is used as a taxonomic tool for investigating species diversity and species level responses to environmental drivers, the diversity of responses hidden within species complexes may not be realized, and the conclusion of generality may mask specific cryptic species responses. In South-East Queensland, Australia, European occupation since the mid 1800’s has seen large scale clearing of native vegetation along streams and rivers in nearly all catchments. As a consequence of this land-use change catchment hydrology has been substantially altered, which, combined with the presence of dams and weirs, has resulted in a decline in water quality of streams in some catchments, which is of growing concern for conservation of species biodiversity. This study aimed to explore cryptic diversity in two species complexes of freshwater aytid shrimps common in South-East Queensland and elucidate species level responses to environmental variation that could explain their spatial distribution. This broad aim was met through three specific studies. First, using regional scale data of cryptic species diversity and water quality, the importance of species-specific responses to environmental conditions in determining spatial distribution patterns and environmental relationships of cryptic species in the Caridina indistincta and Paratya australiensis species complexes was examined. To accomplish this aim, DNA sequences were used to identify shrimp specimens from 89 sites in 17 catchments spanning the study area. In addition, an assessment of eight morphological traits was used to test whether these cryptic species could be morphologically identified. Use of these eight traits did allow species level identification, at least in South-East Queensland. However, caution is suggested in the use of these morphological traits for recognising species, due to the probability of morphological plasticity within a species across broad spatial scales. Ordination analysis of presence-absence data showed that the five cryptic species within the two species complexes showed spatially distinct distributions across streams in SEQ, with each cryptic species displaying different relationships with individual environmental variables. For species in the Caridina indistincta complex, C. indistincta sp. B was significantly associated with elevation, C. indistincta sp. D was significantly correlated with dissolved oxygen range, whilst, individuals of C. indistincta sp. A were negatively associated with elevation and dissolved oxygen range. This may indicate that C. indistincta sp. A tended to inhabit sites with low elevation and perhaps having a higher tolerance to a low range of dissolved oxygen. For the Paratya australiensis species complex, P. australiensis lineage 4 and 6 showed significant correlations with elevation and conductivity, respectively. The second broad aim of the study was to explore these spatial patterns at smaller geographical scales and with greater detail about water quality to understand and quantify the fundamental environmental factors (e.g., physical chemical water parameters and concentrations of heavy metals) that are potentially shaping the current distribution patterns and abundance of cryptic species within the two species complexes. To explore this aim, sediment samples from 22 sites in 13 catchments in SEQ were analysed to determine concentrations (mg/kg dry weight) of 11 heavy metals. Additionally, a number of water quality variables were measured in situ, including: elevation, stream width, stream temperature, dissolved oxygen, conductivity, pH, total dissolved solids, and turbidity. Also, a water sample was taken from each site for laboratory analysis of: Ammonium nitrogen (NH4-N), Dissolved oxidized nitrogen (Nitrate+Nitrite) (NOX-N), Total nitrogen (TN), Total kjeldahl nitrogen (TKN), Total kjeldahl phosphorus (TKP), Orthophosphate-P (PO4-P). Shrimps were collected from each site and identified to species using both morphology and DNA sequencing. The morphological identification of each adult individual (except juveniles which were genetically analysed) was used as a measure of absolute abundance and the genetic ‘checking’ of a set number of individuals in each sample was used to compute relative abundance. Redundancy analysis (RDA) showed that the spatial distribution and absolute and relative abundance of C. indistincta sp. D and sp. B were significantly positively influenced by elevation, while the relative abundance of P. australiensis Lin.6 was significantly positively affected by the concentration of manganese (Mn). Stream Total nitrogen (TN) was significantly positive driver of the spatial distribution and relative abundance of C. indistincta sp. A, while Orthophosphate-P (PO4-P) was significantly positive driver for the absolute and relative abundance of this species. Further analysis, this study confirms that P. australiensis Lin.6 was more tolerant of heavy metal concentrations compared with other cryptic species, as its distribution and absolute and relative abundance were significantly positively correlated with the concentrations of manganese, iron and cobalt. In contrast, C. indistincta sp. A was more sensitive to these metals than other study species. These results demonstrated that cryptic species of freshwater atyid shrimps of the C. indistincta and P. australiensis species complexes were different in their environmental requirements. As well, the cryptic species of both complexes were identified to have different associations with heavy metal concentrations, indicating that these species were different in their tolerance to toxicants. Finally, the third aim of the study was to further examine the differences in sensitivity to heavy metals (Copper and Zinc) among cryptic species of the two study complexes experimentally in the laboratory. Two cryptic species of each complex were used as study species, C. indistincta sp. A and sp. D and P. australiensis Lin.4 and Lin.6. The field studies showed differences among these species in their correlations with metal concentrations, and therefore they were seen as good candidate species for testing differences in the sensitivity to metal toxicants. Each cryptic species was exposed to six concentrations of each metal Cu or Zn using an acute (96-h) toxicity test. The results from this study were generally showed contrasting correlation between species and heavy metals; P. australiensis Lin.6 was the most tolerant species to both study metals, while C. indistincta sp. A was more sensitive to copper, and C. indistincta sp. D was more sensitive to Zn compared with the other tested species. Furthermore, the exposure of individuals of each species to the heavy metals caused changes in both their behaviour and their colour during exposure time. Overall, this study has shown cryptic species within broad species complexes can vary in their spatial distribution and their tolerance and response to water quality parameters. This highlights the advantage of using analyses of biotic and abiotic variables for ecological management and biodiversity conservation and the need to understand true species diversity when looking at species level responses to environmental degradation.

Effects of grassland management on plants and invertebrates in Transylvania, Romania : a threat to local biodiversity hotspots

این تحقیق جهت مقایسه تنوع زیستی علف‌های‌هرز بوم‌نظام‌های برنج (Oryza sativa L) شهرستان‌های بابل و بابلسر انجام گردید. نمونه‌ها از شش مزرعه دو نظام مدیریتی (ارگانیک و پرنهاده)، در سال زراعی 91-1390، جمع‌آوری شد. داده‌ها (شامل تعداد گونه‌های علف‌هرز و فراوانی هر یک) از نُه کوادرات (یک×یک متر) هر مزرعه، طی چهار مرحله (پنجه‌زنی، ساقه‌روی، پرشدن دانه و پس از برداشت) به‌دست آمد. مقایسه میانگین شاخص-های تنوع زیستی دو نظام مدیریتی، نشان داد که علی‌رغم افزایش مقادیر شاخص‌های تنوع در نظام ارگانیک، اختلاف معنی‌داری بین دو نظام قابل مشاهده نبود. مقایسه مراحل مختلف نمونه‌برداری بر اساس میانگین دو نظام، حاکی از کاهش تنوع و یکنواختی علف‌های‌هرز در مرحله چهارم (پس از برداشت) بود. ارزیابی شاخص‌های تنوع زیستی دو نظام پرنهاده و ارگانیک نیز حاکی از کاهش معنی‌دار شاخص‌های تنوع زیستی علف‌های‌هرز در مرحله چهارم نسبت به مراحل قبلی بود. این نتیجه می‌تواند به‌علت تخریب ایجاد شده در بوم‌نظام‌های برنج، ناشی از برداشت محصول و فراهم شدن زمینه برای ظهور گونه‌های مختلف علف‌هرز باشد. علی‌رغم اینکه در این شرایط انتظار افزایش تنوع می‌رود، اما به‌واسطه وجود تنش خشکی در مرحله برداشت، گونه‌های مقاوم به تنش ظاهر شده و مستقر گردیدند. برتری تنوع در نظام ارگانیک، به‌ویژه در مرحله چهارم را می‌توان به ظهور و استقرار علف‌های‌هرز مقاوم به شرایط تخریب و تنش مانند علف انگشتی (Digitaria spp.)، توق (Xanthium strumarium L.) و اکلیپتا (Eclipta prostrata L.) (گونه‌های شرایط غیرغرقاب) علاوه بر علف‌های‌هرز رایج (گونه‌های شرایط غرقاب) بوم‌نظام برنج مانند سوروف (Echinochloa crussgalli P. Beauv) و گونه‌های اویارسلام (Cyperus spp.) نسبت داد. نتیجه این که در مجموع، شاخص‌های تنوع زیستی (تنوع و یکنواختی) علف‌های‌هرز در نظام ارگانیک نسبت به رایج برتری داشت.

Ecological impact of phytoinvasions in Ukraine

Competition and coexistence of reef-corals

شاخص‏های تنوع زیستی ابزاری نیرومند برای ارزیابی پایداری نظام های کشاورزی محسوب می شوند. در این تحقیق که به منظور ارزیابی تنوع زیستی محصولات زراعی و باغی شهرستان های استان اصفهان و همچنین بررسی روابط موجود بین تنوع زیستی و عوامل اقلیمی ‏این استان صورت گرفت، سطح زیر کشت، غنای گونه ای، یکنواختی، تنوع گونه ای و تنوع آلفا و بتای محصولات زراعی و باغی محاسبه شده و مورد ارزیابی قرار گرفتند. بدین منظور، اطلاعات مربوط به سطح زیر کشت گیاهان زراعی و باغی شهرستان‏های مختلف استان اصفهان در سال زراعی 92-1391 از طریق اطلاعات سازمان جهاد کشاورزی استان و همچنین پرسشنامه‏هایی جمع‏آوری گردید. محصولات زراعی به هشت گروه غلات، حبوبات، جالیزی، سبزیجات، علوفه ای، صنعتی و دارویی و محصولات باغی به دو گروه درختان میوه معتدله و گرمسیری طبقه بندی شدند. تنوع آلفا و بتا نیز با استفاده از رابطه غنای گونه‏ای مساحت برای اقلیم‏های مختلف استان محاسبه شد. نتایج نشان داد که در گروه محصولات باغی، درختان میوه معتدله (2/76 درصد) بیشترین و در گروه محصولات زراعی غلات (36/59 درصد) و گیاهان دارویی (09/1 درصد) به ترتیب بیشترین و کمترین سطح زیر کشت را دارا هستند. شهرستان های سمیرم و برخوار و میمه به ترتیب بیشترین و کمترین سطح زیر کشت محصولات باغی را به خود اختصاص دادند. بیشترین سطح زیر کشت محصولات زراعی در شهرستان اصفهان و کمترین آن در شهرستان خوروبیابانک مشاهده شد. شهرستان-های کاشان، لنجان، و نطنز با 17 گونه گیاهی، بیشترین و آران و بیدگل با سه گونه گیاهی کمترین غنای گونه ای محصولات باغی استان را در برداشتند. بیشترین و کمترین شاخص یکنواختی محصولات باغی به ترتیب مربوط به شهرستان های اصفهان (83/0) و سمیرم (192/0) بود. شهرستان های فلاورجان، خمینی شهر، کاشان، نایین و نجف آباد دارای بیشترین شاخص یکنواختی در محصولات زراعی و شهرستان اصفهان کمترین میزان این شاخص را نشان داد. به طور میانگین بیشترین و کمترین شاخص تنوع زیستی شانون- وینر در محصولات زراعی به ترتیب مربوط به گیاهان علوفه ای (929/0) و جالیزی (442/0) بود. این شاخص برای درختان معتدله بیش از دو برابر درختان گرمسیری گزارش شد. بیشترین و کمترین میزان تنوع آلفا به ترتیب در شهرستان‏های واقع در اقلیم‏های معتدل و بیابانی گرم مشاهده شد. اقلیم بیابانی معتدل نیز بالاترین میزان تنوع بتا را شامل شد.

Climate change will significantly affect avian biodiversity on a global scale. Increasing temperatures over the next century will lead to shifts in species distributions, alterations in the timing of breeding and migration, changes in morphology and shifts in genetic frequencies among avian populations. The global hotspots of avian diversity are found in mountainous rainforests, regions which may be difficult to access. Therefore, effective ways of monitoring rainforest bird assemblages are vital, for both ecologists and conservationists. This thesis addresses the challenge of monitoring the effects of climate change on rainforest bird assemblages. I used two methods, point counts and automated acoustic recording, to sample the rainforest birds occupying three elevational gradients in rainforests on the east coast of Australia. In doing so, I had the following aims: 1) to determine whether biodiversity data from automated acoustic recordings made using automated recording units (ARUs) was comparable to data generated using a traditional method (point counts), 2) to assess the ability of ARUs to monitor cryptic rainforest species for long time periods, 3) to identify birds that could be used as indicator species of elevation for the purpose of long-term climate change monitoring, and 4) to investigate the driving factors of bird species richness and abundance along elevational gradients in Australian rainforests. Existing studies showed contrasting results when comparing the effectiveness of traditional avian sampling methodologies with ARUs. To address this in an Australian rainforest context, we collected data on the birds of Eungella National Park in central Queensland over two sampling periods. We found that data from point counts and ARUs was broadly similar. On average, point counts detected more species than recordings of the same duration. The respective strengths and weaknesses of point counts and ARUs are complementary, and they should be used simultaneously in future biodiversity surveys. ARUs can sample remotely, simultaneously, and for long time periods. Using ARUs, we collected a year’s worth of data on two cryptic species inhabiting rainforest in north-eastern New South Wales. Bassian Thrush Zoothera lunulata and Russet-tailed Thrush Z. heinei are secretive inhabitants of wet forests on the eastern coast of Australia. We found that the two species had differential elevational preferences: Bassian Thrush preferred elevations above 900m asl, and Russet-tailed Thrush preferred elevations below 700m asl. Recordings of song indicated that Russet-tailed Thrush bred earlier than Bassian Thrush in 2015. This, along with the elevational preferences of the two species, may be related to temperature. The use of ARUs enabled us to quantify the elevational preferences and likely breeding times of these cryptic species. Populations of Bassian Thrush in north-eastern New South Wales and south-eastern Queensland are likely to decline with increasing temperatures. Upwards shifts in the elevational ranges of rainforest birds are expected due to increasing global temperatures. Identifying the current elevational distributions of indicator species has been suggested as one way of monitoring such upwards shifts. Previous research in our study region had identified indicator species among various invertebrate and plant taxa, but information on vertebrate indicators was lacking. Using data on the elevational preferences of birds collected over one year, we identified avian indicators of lowland and highland rainforest sites in north-eastern New South Wales. These indicators may be used to detect future shifts in species elevational preferences in the region. Previous research in tropical rainforests of the Wet Tropics identified temperature as an important driver of bird species’ distributions. There was a comparative lack of information for the subtropical rainforests of north-eastern New South Wales. Our data from elevational gradients in this region indicated that temperature was significantly positively correlated with both avian species richness and abundance. Species richness declined with elevation; there was no consistent elevational pattern in abundance. We found that species’ functional traits mediated their responses to the changes in environmental conditions along the gradient: large-bodied and small-bodied species are likely to be affected in different ways by increasing temperatures. My research has determined effective ways of monitoring the effects of climate change on rainforest bird assemblages. In doing so, I have also addressed major gaps in the knowledge of two relatively understudied biodiversity hotspots on the eastern coast of Australia. The baseline data presented in this thesis allows future researchers to detect changes in the avian biodiversity of the study regions, and represents a significant contribution to ornithology and climate change research in Australia and internationally.

Impacts of invasive plants on soil fungi and on above- and belowground plant diversity in temperate forests

Semi-natural grasslands including hay meadows belong to the most species-rich habitats in central Europe and are therefore of high conservation value. The high biodiversity of these grasslands has been maintained for many centuries through the regular disturbance by traditional management practices. In the Valais, an arid mountain region of Switzerland, traditional management of hay meadows includes irrigation by open water channels. In the past decades, however, the traditional irrigation technique was increasingly replaced by more efficient sprinkler-irrigation systems or irrigation was stopped on marginal and poorly accessible areas. Within the scope of this thesis, four studies were conducted to investigate different aspects of these changes in meadow irrigation. The aim of the first study was to examine whether land-use abandonment resulting from the cessation of irrigation influenced the biodiversity of hay meadows in the Valais. For this purpose, plant and gastropod surveys were conducted in three serial stages of succession (hay meadows, early abandoned meadows and young forests). Meadow abandonment resulted in an increase in gastropod species richness and a loss of plant and gastropod species characteristic for open grassland habitats. Furthermore, functional traits of plants (plant height, the start of seed shedding and the type of reproduction) and gastropods (shell size) were affected by abandonment. Traditional meadow irrigation is assumed to distribute the water more heterogeneously than sprinkler irrigation, which might affect meadow biodiversity as well as the distribution of plants in a small scale. The aim of the second study was to examine whether the change from traditional to sprinkler irrigation affected the local biodiversity (plants and gastropods) of hay meadows in the Valais. A high plant species richness was found in the hay meadows investigated. The diversity and composition of plant and gastropod species did not differ between traditionally and sprinkler-irrigated meadows. However, the installation of sprinkler systems resulted in an increase in the grass-to-forb ratio and affected the leaf distribution and the start of seed shedding in plants. The third study aimed to investigate whether the change in irrigation technique affected the small-scale distribution of plants and soil characteristics in these hay meadows. Three sampling plots consisting of 13 subplots of increasing size were installed in traditionally and sprinkler-irrigated meadows to assess plant species richness and soil characteristics within subplots. The type of irrigation technique did not affect the shape of the plant species-area relationship. Furthermore, spatial autocorrelation in the soil characteristics examined was low and their small-scale distributions were mostly not influenced by the irrigation technique. These findings indicate a pronounced small-scale heterogeneity in the distribution of plant species and soil characteristics in the hay meadows investigated. Therefore, as practiced in our study areas, the distribution of water by sprinklers might be less homogenous than commonly assumed. The abandonment of traditional management practices of semi-natural grasslands is suggested to result in a reduced landscape heterogeneity, which in turn might contribute to the loss of local plant diversity. The fourth study aimed to investigate whether the change from traditional to sprinkler irrigation resulted in alterations in the surrounding landscape of species-rich hay meadows. Furthermore, we asked if plant diversity of differently irrigated meadows is influenced by landscape composition and the heterogeneity of the surrounding landscape. Landscape composition was more diverse for traditionally than for sprinkler-irrigated meadows, but did not differ prior to the installation of sprinklers. A diverse small-scale landscape composition in the close surroundings of hay meadows had a positive effect on the number of generalists but not on total plant species richness or the number of specialists. Finally, sprinkler-irrigated meadows had an increased number of generalist plant species. The findings of this thesis suggest that the installation of sprinklers did not affect the local species richness of plants and gastropods in the hay meadows investigated. Nevertheless, the change in irrigation technique influenced functional aspects of plant diversity (plant traits, grass-to-forb ratio and generalist species). Furthermore, the installation of sprinklers was associated with a homogenization of the landscape, which may eventually result in an intensification of land use. For the conservation of the biodiversity of these hay meadows it is recommended to maintain the relatively extensive irrigation and management practices.

Biodiversity and ecological functioning of mudflat macrofauna in the Anthropocene

There is a great importance of dingaputa haor in fish production, maintaining biodiversity, meeting local demand and regional demand and also serve as the good source of fish seed supply for other water bodies. So a study was undertaken to evaluate the present situation of fish biodiversity of fish species in this region. During the study period 49 species of fish fauna including shrimp species were recorded. Among them, 7 species of carps, 12 species of catfishes, 4 species of snakehead, 5 species perches, 3 species of eels, 6 species < barbs, 2 species of minnows, 3 species of clupied species and other miscellaneous 7 species including shrimp mainly Macrobrachium rossenbergii and Macrobrachium malconsonii were recorded. The highest intensity and abundance were found in eel and clupeid. This result may be due to availability and broad distribution of eel and clupeid throughout the year and all kinds of water bodies. Some reasons are found which are liable for the loss of fish biodiversity such as Degradation of wetland beds due to heavy sedimentation and death of most of the wetlands in winter, Cultivation of rice or other field crops by artificially drying wetlands destroys natural fish habitat, Catch of wide number of small indigenous fishes and egg laying species of fish, Destruction of small indigenous fishes by using chemicals termed them as weed fish species and enhancement of water reclamation. Steps should be taken as early as possible to prevent further degradation.

Stratégies villageoises pour la gestion des paysages forestiers du Menabe Central, Madagascar

A multi-disciplinary evaluation of the hybrid anemonefish Amphiprion leucokranos: behaviour shaping evolutionary outcomes of hybridization