Grassland Patches Research Articles

Habitat availability and climate warming drive changes in the distribution of grassland grasshoppers

Land use and climate change are considered the major drivers of current insect declines. However, in intensively used agricultural landscapes the impacts of both on Orthoptera (hereinafter termed ‘grasshoppers’) are still poorly understood. We analysed grasshopper assemblages in two grassland types (patches, N = 63 and verges, N = 118) by comparing two surveys – one in 1995 and one in 2012 – in an agricultural landscape of the NW-German Lowland. Despite the short time period between the two surveys, we detected strong changes in environmental conditions and grasshopper assemblages. In contrast to grassland verges, grassland patches suffered from severe habitat loss. More than a quarter of all grassland patches were converted to other biotope types, in particular, arable fields cropped with maize. Additionally, summer temperatures rose by 1.1 °C. Species richness and the Community Temperature Index also increased in grassland patches and verges. By contrast, the Community Farmland Index decreased. The ongoing cultivation of maize as a bioenergy crop was responsible for a severe loss of grassland patches leading to a homogenization at the landscape level. However, due to the high connectivity of grasslands, thermophilous and generalistic grasshopper species with both low and high dispersal ability were able to track global warming. Based on our study, (i) the availability of suitable habitats and (ii) climate warming were the major drivers of grasshopper assemblage shifts. With the ongoing loss of grassland patches, grassland verges become increasingly important not only as dispersal corridors, but also as refuges for biodiversity.

Macroecology of North European Wet Grassland Landscapes: Habitat Quality, Waders, Avian Predators and Nest Predation

Wet grassland degradation is a global issue that involves both altered land cover patterns and ecological processes, which affect the distribution and abundance of species. The sharp decline in European wader bird (Charadrii) populations is a good example. The aim of this study is to test the hypothesis that the anthropogenic developmental stage of wet grassland habitats and landscapes drives avian nest predator abundance, and thus the predation pressure on nests, which is a major cause of wader bird declines. Using a macroecological approach we selected six wet grassland landscapes representing a gradient in both grassland habitat development and breeding wader population status in four European countries (Belarus, Iceland, Lithuania and Sweden). We (1) mapped wader and avian predator assemblages in multiple wet grassland patches in each landscape, (2) used artificial nests to estimate the relative rate of egg predation, and (3) analyzed relationships between nest predation pressure, corvid nest predators versus raptors, nest loss and the stage of wet grassland habitat and landscape development. We found (1) inverse relationships between the abundance of corvids and waders, as well as between wet grassland developmental stage and waders, and (2) a positive correlation between the probability of nest loss and the density of corvid birds. In conclusion, we found a clear macroecological pattern linking habitat quality, wader populations, nest predators and nest predation. These linkages stress the importance of including nest predation as a factor limiting wader bird populations, and that corvid control or management may be useful management tools.

Conservation planning for pollinators in the U.S. Great Plains: considerations of context, treatments, and scale

AbstractPopulations of many species of grassland‐associated butterflies, moths, and bumblebees in the Great Plains of North America are experiencing steep declines due to habitat loss and degradation—primarily conversion of grasslands to row‐crop agriculture and invasion of woody plants and exotic cool‐season grasses—and insecticide use. These declines are exacerbated by the generally limited dispersal ability of insects, which make local populations susceptible to extirpation following habitat fragmentation. Interest in pollinator conservation has grown substantially in recent years, but information to guide pollinator conservation across the region is limited. We used pollinator biology along with principles of landscape ecology and metapopulation dynamics to develop a simple decision matrix based on patch size and inter‐patch distances to guide landscape‐scale grassland conservation efforts in the U.S. northern Great Plains. When applied to spatial land cover data depicting potential pollinator habitat, the matrix uses landscape characteristics to guide placement of conservation treatments to help ensure persistence of target pollinator populations. Patch size and connectivity thresholds can be set to match characteristics of target species, but in all cases, local management will be necessary to ensure that fine‐grained features such as nectar sources and host plants are present. Applying the matrix to habitat layers for a nine‐state analysis region showed substantial geographic variation in conservation needs, opportunities, and potential treatments. We also demonstrate that non‐native planted cover such as alfalfa and certain grasslands enrolled in the Conservation Reserve Program can substantially enhance landscape structure by increasing grassland patch size and core area while decreasing distance between patches. Pollinators dependent on native prairie will also benefit from planted cover that provides nectar sources and serves as a buffer from pesticides associated with croplands. Consistent with the principles of strategic habitat conservation, targeted monitoring and research will be necessary to validate and adapt the model to meet local conditions.

Effects of Grassland Patches on the Composition and Stability of Soil Aggregates in the Qinghai-Tibet Plateau

Grassland patchiness was an important process in the succession of grassland degradation. The changings of soil aggregates were affected by grassland patches, which in turn affect soil organic carbon mineralization. In this study, the soil aggregates were divided into three particle sizes: macroaggregates (2-0.25mm), microaggregates (0.25-0.053mm) and clay-silt aggregates (<0.053mm) through the wet sieve method. The indoor culture method measured the cumulative mineralization of soil organic carbon. The study analyzed the changes of soil aggregates in the grassland patches of the Qinghai-Tibet Plateau, and the influences of soil aggregates on the soil organic carbon mineralization. The results of the study showed that grassland patches caused significant differences in soil aggregates. Compared with native vegetation, single plant patches and bare area formed by degradation would reduce the stabilities of aggregates and increased the amount of organic carbon mineralization. Soil aggregates of grassland patches have a significant effect on the cumulative mineralization of organic carbon. Therefore, study of changes in soil aggregates and the impacts of aggregates on organic carbon mineralization would help to accurately understand the future carbon cycle of terrestrial ecosystems and climate changes.

Land-use modifications and ecological implications over the past 160 years in the central Apennine mountains

ABSTRACT Today’s Mediterranean landscapes result from the interaction between ecosystems and anthropogenic activities. This study aims to assess how the land-use changes between the mid-nineteenth and end of the twentieth century influenced the temporal continuity of the ecosystems in central Apennines (central Italy). Information was acquired from Gregorian cadastral maps, orthophotos and aerial photos (1850, 1954, 1980 and 2010), digitised and georeferenced using QGIS 3.10.1 software. Marked changes in land-use types were found. From 1850 to 1954, grasslands were widely transformed into arable lands, but in the next 60 years they changed again into new grasslands and forests. Forests underwent a slow but continuous expansion from 1850 to 2010. Only a small percentage of the forest and grassland patches (14 and 16%, respectively) have seen ecological continuity. These considerations call attention to temporal continuity of ecosystems, together with the historical dynamism of landscapes, in defining land management and nature conservation policies.

A cross‐disciplinary forum promoting efficient biodiversity conservation in “new” grasslands in Sweden

AbstractDue mainly to changes in land use, high nature value grasslands are becoming increasingly rare in agricultural areas. As a consequence, biodiversity is decreasing and many species are facing the risk of extinction. At the same time, the present‐day landscape contains many “new” grassland habitats, for example golf courses, roadside verges, power line corridors, and railway banks. These habitats are well distributed over the landscape with a potential to connect remnant patches of valuable grasslands. As all kinds of grasslands, they need appropriate management to preserve biodiversity. To achieve this, innovative solutions are needed. In order to exchange knowledge and experiences in this field, we established a cross‐disciplinary working group, with members from a large number of National authorities, Universities, power grid companies, and various other stakeholders such as the Swedish Golf Federation. This group has become an invaluable forum for project cooperation and discussions about practical management issues, monitoring, and research. After 10 years we are now approaching a common understanding on how infrastructure habitats can play an important role in nature conservation. At present, this has led to adaptive management of a large number of high value grasslands, for example in power line corridors, along roadside verges, and on golf courses. In addition, three landscape‐scale projects have been initiated with the long‐term aim to establish a green infrastructure.

Island biogeography theory predicts plant species richness of remnant grassland patches in the agro-pastoral ecotone of northern China

Habitat loss and fragmentation are critical threats that cause biodiversity loss. However, the driving factors of species diversity in fragmented habitats are complex. This study was conducted in the agro-pastoral ecotone of northern China, a region that has suffered from severe habitat fragmentation due to agricultural activities. Based on the plant species richness, patch characteristics (patch area, fractal dimension, and isolation), landscape characteristics (grassland area ratio within buffer zones with different radii (50–500 m) around each patch), and environmental characteristics (mean annual precipitation, mean annual temperature, altitude, extremely high temperature, extremely low temperature, slope, and aspect) of 82 remnant grassland patches, we first explored the appropriate buffer zone with the most powerful impact on species richness of remnant grassland patches (SRP). Furthermore, we analyzed the relationships between a series of predictors and SRP. Finally, we confirmed the critical driving factors of SRP through a random forest analysis. The results showed that the landscape scale with the most powerful impact on SRP was 150 m. The patch area, grassland area ratio of a buffer zone with a 150 m radius, mean annual precipitation, and slope all had significantly positive effects on SRP. Among these factors, patch area and patch isolation were the top two driving factors of SRP. Our study suggests that large and highly connected patches should be protected for the construction of natural reserves. Meanwhile, the habitat around patches within a suitable range should also not be ignored. We highlight that the island biogeography theory could be used to predict plant species richness of remnant grassland patches in the agro-pastoral ecotone of northern China.

Woody encroachment in grassland elicits complex changes in the functional structure of above‐ and belowground biota

AbstractWoody plant encroachment affects dry grasslands globally. To predict changes in biodiversity and ecosystem processes, it is important to understand how this process affects the functional composition of grassland organism groups. In this context, seminatural wooded meadows represent a form of experimental manipulation—where open grassland and woody patches co‐occur in homogeneous environmental conditions due to human management decisions—which provides an opportunity to address the effect of woody plant encroachment on vegetation and soil biota. We used environmental DNA metabarcoding to address variation in plant, soil fungal, and soil animal communities in parallel. We also addressed functional groups of fungi—animal and plant pathogens, saprotrophs, decomposers, arbuscular mycorrhizal, ectomycorrhizal, endophytic, and other symbiotrophic fungi—and of soil animals—fungivores, bacterivores, litter feeders, root feeders, macro plant feeders, algal/lichen feeders, predators, and parasites. Co‐variation between communities was detected from aboveground vegetation plots and metabarcoding of soil DNA, in terms of estimated richness and compositional patterns. Differences between open and wooded patches were most pronounced among plants and symbiotic fungi, whereas soil animals exhibited less marked differences. For most organisms, mean richness, as well as total richness per habitat type, was higher in open than wooded patches, but ectomycorrhizal fungi exhibited the opposite pattern. The functional structure of the soil biotic community, as characterized by the proportion of DNA sequences attributed to different functional groups, differed significantly between open and wooded grassland patches, with symbiotic fungi (arbuscular mycorrhizal, ectomycorrhizal, and other symbiotrophic [mostly orchid mycorrhizal] fungi) contributing most to the difference. This study supports the notion that a soil DNA‐based metabarcoding approach can provide insights into the diversity and composition of multiple taxonomic groups in natural ecosystems. It also provides a first demonstration of the complex changes to the functional structure of the belowground community that accompany woody plant encroachment in grasslands.

Disturbance reshapes the productivity–diversity relationship

AbstractQuestionWe evaluated the effect of disturbance on the productivity–diversity relationship in a long‐term monitoring study. We asked whether the same productivity–diversity relationship applies to 12 years of pre‐fire (undisturbed) conditions and to eight years of post‐fire succession studied in the same plots.LocationBugac, Kiskunság, Central Hungary.MethodsWe studied 20 permanent plots for 20 years in grassland patches of a forest–steppe vegetation complex, 12 years before (2000–2011), and eight years after (2012–2019) a severe wildfire. The cover values of each vascular plant species were visually estimated each year. We used total cover as a proxy for productivity and species richness as a measure of diversity. We assessed changes in the productivity–diversity relationship before and after the disturbance event. Temporal changes of the pre‐fire and post‐fire relationship were analysed separately by generalized estimation equations in the R environment.ResultsIn the pre‐fire period, we found a positive linear productivity–diversity relationship, and no time effect. However, in the post‐fire period, we found a unimodal relationship, which changed gradually from year to year. The disturbance event moved the vegetation out of a stable state, increased the range of both productivity and diversity, and resulted in a decreasing linear component of the relationship after the fire. Our results provide a striking example of the influence of succession on the shape of the productivity–diversity relationship.ConclusionsDisturbance may create considerable and long‐lasting changes in the productivity–diversity relationship of formerly stable communities. The changing shape of the productivity–diversity relationship over time after disturbance suggests that the evaluation of broad‐scale productivity–diversity relationships should control for disturbance history.

Grassland vegetation and roads have dominant influence on decadal-scale spatial-temporal patterns of fires in a species-rich protected Terai habitat in northeastern India

The Terai ecoregion of the Himalayan foothills is among the most fire-affected ecosystems in the Indian sub-continent. Although most of the Terai has already been lost to agriculture and urbanization, the few remaining native habitats are strictly protected due to their high biodiversity and ecological importance. The use of fires to maintain vegetation and wildlife habitat in these protected areas is an integral part of forest management. Although fires are initiated by forest managers or local people, their eventual spread and behaviour are not controlled. We hypothesize that distributions of fires are determined by several direct and indirect drivers like fuel load, fuel moisture content, presence of natural or artificial fire breaks, and climatic attributes of precipitation and temperature. Using the moderate-resolution (375m) satellite sensor-based data we studied the environmental influence on the spatial-temporal patterns of fire events over 18 years (2000-2018) in a 519 km2 protected area in northeastern India. The park has a mosaic of vegetation formations – including dry and swampy alluvial grassland, early successional woodland, and moist tropical forest. Despite high rainfall, there is an intense dry season that renders the herbaceous vegetation susceptible to fires. Using spatial and spatial-temporal Poisson regression models in a rigorous conditional autoregressive Bayesian framework, we found that net primary productivity (a proxy of vegetation type and fuel load), distance to roads (a measure of human influence), elevation (through its influence on floods and vegetation type), and river area extent (by determining the area under vegetation) had a significant influence on the spatial distributions of fires. The climatic signal on interannual variation in fires was weak, but dry season rainfall reduced fire incidence. The disproportionate distribution of fires adjacent to roads compared to the interior, and the repeated burning of some grassland patches need to be addressed in fire management.

Decline of White-throated Bushchat Saxicola insignis Gray J.E. & J.R. Gray, 1847 (Aves: Passeriformes: Muscicapidae) in Nepal: implications on its global status

The White-throated Bushchat, also known as Hodgson’s Bushchat, is a long-distance migratory and specialist grassland bird categorized as Vulnerable on the IUCN Red List. In Nepal, White-throated Bushchat winters in the lowlands, and has been primarily recorded in large Phantas (=open plains of grassland). We present the population status of the species in Shukla Phanta, the largest continuous lowland grassland in Nepal that is known to hold the largest wintering population of White-throated Bushchat in the Indian subcontinent. Our 2013–2014, 2016–2017, and 2017–2018 winter surveys for White-throated Bushchat followed the same method used in the 1997–1998 and 2007 surveys in Shukla Phanta for comparable assessment of the status of the species. Our study provided overwhelming evidence that the species has undergone a steep decline over the last two decades (probability of 92% for a decline greater than 5% per year). Shukla Phanta is dominated by the species’ preferred habitat of Imperata cylindrica, Narenga porphyrocoma, and Saccharum bengalensis. Grassland patches managed through controlled burning leaving enough reeds for perches, grazed at medium level of intensity by wildlife and within close distance to water were found to support higher numbers of White-throated Bushchat. Given the observed steep decline in the largest known wintering population of the species and similar declines observed in the wintering populations in India, its status warrants uplisting to Critically Endangered, and we recommend an urgent review of its global status.

Modelling the Impacts of Habitat Changes on the Population Density of Eurasian Skylark (Alauda arvensis) Based on Its Landscape Preferences

The dramatic decline of the abundance of farmland bird species can be related to the level of land-use intensity or the land-cover heterogeneity of rural landscapes. Our study area in central Europe (Hungary) included 3049 skylark observation points and their 600 m buffer zones. We used a very detailed map (20 × 20 m minimum mapping unit), the Hungarian Ecosystem Basemap, as a land-cover dataset for the calculation of three landscape indices: mean patch size (MPS), mean fractal dimension (MFRACT), and Shannon diversity index (SDI) to describe the landscape structure of the study areas. Generalized linear models were used to analyze the effect of land-cover types and landscape patterns on the abundance of the Eurasian skylark (Alauda arvensis). According to our findings, the proportions of arable land, open sand steppes, closed grassland patches, and shape complexity and size characteristics of these land cover patches have a positive effect on skylark abundance, while the SDI was negatively associated with the skylark population. On the basis of the used statistical model, the abundance density (individuals/km*) of skylarks could be estimated with 37.77% absolute percentage error and 2.12 mean absolute error. We predicted the skylark population density inside the Natura 2000 Special Protected Area of Hungary which is 0–6 individuals/km* and 23746 ± 8968 skylarks. The results can be implemented for the landscape management of rural landscapes, and the method used are adaptable for the density estimation of other farmland bird species in rural landscapes. According to our findings, inside the protected areas should increase the proportion, the average size and shape complexity of arable land, salt steppes and meadows, and closed grassland land cover patches.

Delineating fragmented grassland patches in the tropical region using multi-seasonal synthetic aperture radar (SAR) and optical satellite images

ABSTRACT Globally, grasslands are declining and are in highly degraded conditions. In South Asia, grasslands are neglected and treated as wastelands. They remain unprotected, highly fragmented, and poorly understood, which has led to a loss of unique biodiversity and livelihoods. Mapping grasslands accurately is a challenge and current maps based on optical remote sensing often over- or underestimate grasslands in South Asia due to the prevalent complex landscape matrix, small patch sizes, and obscuring monsoonal clouds. Synthetic Aperture Radar (SAR), fused with moderate spatial resolution optical data, has been used to delineate grasslands, but the high-resolution, freely available European Space Agency (ESA)’s Sentinel-1 (SAR) and Sentinel-2 (Optical) provide an opportunity to map small and fragmented patches. Further, high-resolution imageries require high computing power, which is often limited to stand-alone machines. Here, we demonstrate that using cloud computing and optimal use of multi-seasonal imagery, one can obtain a highly accurate land-cover land use (LCLU) classification for a complex habitat matrix. We performed LCLU classification using the Support Vector Machine (SVM) algorithm of Sentinel-1, Sentinel-2, and Sentinel-1 and Sentinel-2 (Combined) in Google Earth Engine (GEE). GEE is a freely accessible cloud computing platform. We compared the accuracy of grassland classes between a) Sentinel-1 seasonal (pre-, during, and post-monsoon), b) Sentinel-2 post-monsoon, and c) combined Sentinel-1 and Sentinel-2. We tested this method at two sites in a highly fragmented habitat matrix in arid and semi-arid areas of Western and Southern India. The classification results have shown that the overall accuracy for the combined image classification was higher than only Sentinel-2 or Sentinel-1 alone for both sites. Grassland class accuracy was also consistent with combined image classification across the sites. Our results identified newer grassland areas that coarse land use management maps used by the government did not. Since the computation was conducted in GEE, a regular laptop was sufficient for the user and processing was completed rapidly. We, therefore, suggest that this approach of using cloud computing and optimal use of resource-hungry (computation and storage) high-resolution Sentinel-1 and Sentinel-2 data can be used to identify major LCLU classes and patchy grasslands in the arid and semi-arid regions of India and has the potential to map at a continent level.

Paleoenvironment of the late Miocene Shuitangba hominoids from Yunnan, Southwest China: Insights from stable isotopes

The Late Miocene witnessed significant changes in climate globally and was an important time in the evolution of hominoids. Here, we report the results of an isotopic study of Late Miocene mammalian teeth and freshwater shells from Shuitangba (Yunnan Province, China) – an important refugium for hominoids, and reconstruct paleoenvironmental conditions in the area. δ13C values of fossil enamel samples range from −15.5‰ to −1.0‰, with a mean of −11.3 ±2.3‰, and δ18O values vary from −14.2 to −4.6‰, averaging −9.7 ±2.2‰. Reconstructed diet-δ13C values for these fossil mammals indicate that although they fed mostly on C3 plants, many of them consumed some C4 vegetation. This suggests that the local ecosystem contained C4 grasses but was dominated by C3 plants. The intra-tooth δ18O variation of fossil herbivores is larger than what is found in modern herbivores. Reconstructed paleo-meteoric water δ18Ow values are on average lower than those inferred from modern samples and also lower than the average δ18Ow values of modern precipitation in the region. Similarly, δ18O values of fossil freshwater shells display a larger seasonal variation and are significantly lower than modern shells from Fuxian Lake in the same region. Thus, the δ18O data from both mammalian teeth and freshwater mollusk shells support a wetter climate, possibly with a stronger precipitation seasonality in the Late Miocene than today. Comparison of clumped isotope temperatures from fossil and modern shells suggests a mean annual temperature of ~15 to 16 °C in the Shuitangba area in the Late Miocene, which is ~3 to 4 °C higher than that of today. Taken together, our isotope results suggest that C4 grasses existed in local ecosystems in the area, likely in patches of grasslands or wooded grasslands in a mostly forested environment in the Late Miocene when the local and regional climate was warmer and wetter than today. Comparison of the δ13C records from Yunnan and the Siwalik region suggests that C4 biomass spread earlier in the Indian subcontinent on the southwest side of the Tibetan Plateau than in Yunnan on the southeast side of the Plateau. The transition from a relatively wet habitat to a more open and drier habitat is also more pronounced and begins earlier in the Siwalik region, relative to Yunnan. These regional differences in climate and ecosystem evolution may be linked to the unique growth history of the Himalayan-Tibetan Plateau.

Specialist Birds Replace Generalists in Grassland Remnants as Land Use Change Intensifies

The ideal free distribution theory predicts that mobile species distribute themselves among habitat patches so as to optimize their fitness. Changes in land use alter the quality of habitat patches and thereby affect the distribution of species. Following the loss of native habitat, habitat specialists are expected to move to patches where native habitat still remains in order to survive. Competition for resources in habitat remnants should consequently increase. As generalists are able to use other habitats, generalists are expected to gradually disappear in remnants in order to avoid increasing competition with specialists. Here, we test these predictions by studying the response of habitat specialist and generalist birds to land-use change in Brazil's southern grasslands. Using a space-for-time substitution approach, we surveyed bird communities in native grassland sites (~4 ha) in 31 regions (10 × 10 km) with differing levels of conversion to agriculture (1–94%). We found a higher abundance of specialists in native grassland patches with increasing agricultural cover in the region, while the total number of individuals in remnants remained constant. At the same time, the share of generalists in total abundance and total species richness decreased. To gain insights into whether these patterns could be driven by shifts in competition, we tested whether generalists that continued to co-occur with specialists in remnants, had less dietary overlap with specialists. As a consequence of community composition in remnants, a higher proportion of generalists were omnivorous and the average generalist species fed less on seeds, whereas the average specialist species fed more on seeds when agricultural cover was high in the region. Our results, therefore, support predictions of the ideal free distribution theory. Specialists that are assumed to have a low survivorship outside of their specialized habitat, distribute to remnants of this habitat when it is converted elsewhere, while generalists, being able to survive in other habitats, disappear gradually in remnants. Such a process could partly explain the segregation of habitat specialist and generalist birds observed in many agricultural landscapes. Finally, our results suggest that native habitat remnants can be important temporary refugia for specialists.

Type and intensity of surrounding human land use, not local environment, shape genetic structure of a native grassland plant.

Landscape heterogeneity can shape genetic structure and functional connectivity of populations. When this heterogeneity imposes variable costs of moving across the landscape, populations can be structured according to a pattern of "isolation by resistance" (IBR). At the same time, divergent local environmental filters can limit gene flow, creating an alternative pattern of "isolation by environment" (IBE). Here, we evaluate IBR and IBE in the insect-pollinated, biennial plant Sabatia angularis (L.) Pursh (Gentianaceae) across serpentine grasslands in the fragmented landscape of SE Pennsylvania, USA using ~4500 neutral SNP loci. Specifically, we test the extent to which radical alteration of the landscape matrix by humans has fundamentally altered the cost of movement, imprinting a pattern of IBR dictated by land use type and intensity, and the potential for IBE in relation to a gradient of heavy metal concentrations found in serpentine soil. We reveal a strong signal of IBR and a weak signal of IBE across sites, indicating the greater importance of the landscape matrix in shaping genetic structure of S.angularis populations in the study region. Based on Circuitscape and least cost path approaches, we find that both low- and high-intensity urbanization resist gene flow by orders of magnitude greater than "natural" habitats, although resistance to low-intensity urbanization weakens at larger spatial scales. While cropland presents a substantially lower barrier than urban development, cumulative human land use surrounding populations predicts within-population genetic diversity and inbreeding in S.angularis. Our results emphasize the role of forest buffers and corridors in facilitating gene flow between serpentine grassland patches and averting local extinction of plant populations.

How do adults of the critically endangered hermit butterfly (Chazara briseis) utilise their habitat? (Lepidoptera, Satyrinae)

Effective conservation of specialised, endangered species depends on the knowledge of all vital resources they require within species’ lifetime. The butterfly Chazara briseis is endangered throughout Europe, especially so in all states north from the Alps. It depends on large areas of open steppe grassland with short and sparse turf. To identify resource use by adult C. briseis butterflies in relation to vegetation structure within its sites. We re-analysed mark-recapture data from the last Czech metapopulation, inhabiting a chain of volcanic hills in Ceske Stredohori highlands and hosting 2000 adults in 2006. We related adult activities observed prior to captures to visually assessed vegetation structures and land cover types obtained from aerial photographs. Additionally, we used land cover types to explore the adults’ home ranges and to compare capture points with randomly selected points. The butterflies displayed clearly structured diurnal activity with nectaring from morning to noon and courtship activities and egg-laying in the afternoons. Both sexes used short-sward patches (egg laying, patrolling), but also patches with taller, flower-rich vegetation (mating, nectaring). These results were corroborated using land cover types, however, with much lower explanatory power. Lifetime utilisation of land cover types (home ranges) differed between sexes, females utilised more shrubby and longer-sward areas than males. Randomly selected points within the sites significantly differed from capture points, the latter contained more open, either short or tall grassland patches. Management of inhabited sites must provide open, short-sward patches alternating with flower-rich taller sward and shrubby patches.

Research on Land Use Change and Ecological Environment Effect Based on Remote Sensing Sensor Technology

In the regional landscape pattern, woodland landscape patches are developed in a regular manner, showing a trend of agglomeration as a whole; the concentration and dominance of landscape patches of cultivated land, grassland, and unused land are decreasing, and the overall situation is fragmented; the water landscape pattern is also showing a regular development state to varying degrees. On the whole, the landscape of a certain area is scattered and fragmented, and the dominant landscape types dominate the overall landscape layout of the region. The diversity of land use landscape pattern shows positive autocorrelation as a whole. According to the Moran’s I index of the diversity of land use landscape patterns, the overall agglomeration effect of the region has increased, but the overall trend is in a balanced trend. The ecological service value of urban land use change continues to increase, but the regional differences are significant, the structure is simple, and it is mainly supported by ecosystems such as forest land, water area, and agricultural land. Based on the analysis of the spatiotemporal evolution of land use, an in‐depth analysis of the urban water environment, atmospheric environment, soil environment, urban heat island, and other environmental issues of the urban land use in the study area is carried out. The calculation and analysis results of the ecological service value of urban land use change and its flow direction change show that the ecosystem service value has increased, and the regional difference and flow direction of the ecosystem service value have changed significantly.

New locality of Lepidium Cartilagineum in the Hortobágy Region (East Hungary)

A new locality of the halophyte Lepidium cartilagineum (J. C. Mayer) Thell. (Brassicaceae) was recorded at the eastern margin of the Hortobágy region, at Nagyhegyes. Despite the fact that the species is not rare in saline steppes in Hungary, it occurs exclusively on solonchak soils. The soil of the one previously documented location at Hortobágy region is not typical solonetz, with transitional solonchak characteristics. The locality found at ‘Sirály-rét’ (Elep, Nagyhegyes) is in a typical alkaline grassland, where the species grows in Puccinellietum limosae and transitional Camphorosmetum annuae communities. This contribution also includes 14 phytocoenological relevés taken at the locality and a comparison of the two, so far documented locations in the region. The author takes the position that this occurrence is to be regarded as native, mostly based on the habitat specifications (such as developed berm formations), vegetation structure and species composition. The continuity of the grassland patch is also proved by available historical maps and aerial photographs.

Long-Term Changes in Spatial Patterns and Life-Stage Structure in a Population of Senecio umbrosus Waldst. et Kit. Along With the Transformation of Grassland Vegetation

This paper was a part of studies conducted within an island population of the ragwort &lt;em&gt;Senecio umbrosus &lt;/em&gt;(White Mt, southeastern Poland), a vulnerable element of xerothermic grasslands. Special attention was paid to the effects of expansive grass encroachment vs. grassland burning episodes on spatiotemporal patterns and life-stage structure of individuals in the population. The population traits were investigated nine times from 1990 to 2010, within three permanent patches differing in soil properties, initial floristic composition, grassland cover (particularly the cover of &lt;em&gt;Brachypodium pinnatum&lt;/em&gt;), ragwort cover and density, shrub/tree cover influencing light intensity (full light–shadow), and grassland burning (zero–six episodes). There was a drastic decline in ragwort abundance within all the study patches accompanied by a decrease in the population clustering coefficient and a gradual equalization of the spatial distribution of ramets. The abundance was negatively correlated (PCA analysis) with an increase in &lt;em&gt;B. pinnatum &lt;/em&gt;cover and positively correlated with the number of burning episodes, which temporarily delimited persistent litter cover and facilitated recruitment of new individuals. The decrease in ramet abundance ranged from 3.8 times (medium-high, moderately shadowed grassland; six cases of burning) to 8.3 times (high, dense, and shadowed grassland; four cases of burning). The patch of low, loose, sunlit, and never-burned grassland with the greatest initial density of ragwort (a 6.8-fold decrease in abundance) has evolved with time into a high and dense grassland with a greater coverage of &lt;em&gt;B. pinnatum &lt;/em&gt;and &lt;em&gt;Calamagrostis epigejos&lt;/em&gt;, additionally shaded by shrubs and young trees.