Wet Meadows Research Articles

Living with Contamination: Insights into an Epigeic Macrofaunal Community in an Area Extremely Polluted by Risk Elements

Five meadows along the Litavka River highly contaminated with heavy metals from mining were sampled for insects and spiders using pitfall traps. The sites are in the Příbram region of central Bohemia, Czechia, which was previously reported as one of the most polluted areas in Europe due to intensive mining and metal processing. The determination of pseudo-total risk elements in soil revealed that all the sampled sites were contaminated with heavy metals, especially As, Cd, Pb, and Zn, with levels ranging from moderate to extreme. The trap results showed a total of 1142 beetles from 21 species, 946 ants from 16 species, 548 spiders from 28 species, and 96 harvestmen from 3 species. With the exception of the scabrous ground beetle, Carabus scabriusculus, all captured specimens were species common to the wet meadows and forest edges of Czechia. With respect to species richness, the dominant spider and beetle taxa were less abundant at the heavily polluted locations than at the moderately polluted locations. In the case of ants, however, there was no relationship between contamination level and abundance or species richness. Thus, it is worthwhile recording and analyzing the differential changes in abundance of the dominant spider and beetle species in polluted areas.

Landscape type affects the functional diversity of carabid beetles in agricultural landscapes

AbstractAgricultural intensification and expansion has been suggested to be a major driver of the loss of biodiversity and associated ecosystem services. Recent studies have shown that landscape‐level effects in addition to on‐site management are of significant importance for insect declines.We here compared carabid beetle (Coleoptera, Carabidae) assemblages of wet meadows among three pairs of highly fragmented ‘modern’ and less fragmented ‘traditional’ agricultural landscapes, using pitfall trapping.Taxonomic diversity and abundance of Carabidae did not differ between modern and traditional landscapes, whereas the proportions of brachypterous, large‐bodied, and habitat specialist species were lower in modern compared to traditional landscapes.These results suggest that landscape type affects functional rather than taxonomic carabid beetle diversity, based on species turnover.To preserve functional diversity in agricultural landscapes, conservation strategies should consider the landscape level in addition to on‐site management, by securing connectivity between remnants of semi‐natural habitats.

A satellite-based monitoring system for quantifying surface water and mesic vegetation dynamics in a semi-arid region

Semi-arid and arid systems cover one third of the earth’s land surface, and are becoming increasingly drier, but existing datasets do not capture all of the types of water resources that sustain these systems. In semi-arid environments, small surface water bodies and areas of mesic vegetation (wetlands, wet meadows, riparian zones) function as critical water resources. However, the most commonly-used maps of water resources are derived from the Landsat time series or single date aerial photographs, and are too coarse either spatially or temporally to effectively monitor water resource dynamics. In this study, we produced a Sentinel Fusion (SF) water resources product for a semi-arid mountainous region of the western United States, which includes monthly maps of both a) surface water and b) mesic vegetation at 10 m spatial resolution using freely available Earth observation data on an open access platform. We applied random forest classifiers to optical data from the Sentinel-2 time series, synthetic aperture radar (SAR) data from the Sentinel-1 time series, and topographic variables. We compared our SF product with three commonly used and publicly available datasets in the western U.S. We found that our surface water class contained fewer omission errors than a leading global surface water product (94 % producer’s accuracy (PA) vs 84 %) and comparable user’s accuracy (UA) (91 % vs 97 %) with commission errors occurring largely in mixed water pixels. Our mesic vegetation class had up to 43 % higher PAs compared to the National Wetlands Inventory (NWI) estimates and up to 78 % higher UAs over the Sage Grouse Initiative mesic resources maps during the most critical part of the water year. We found that while inclusion of SAR data from the C-band Sentinel-1 sensor consistently improved estimates of water resources in each of the last four months of the 2021 water year when compared to optical-only + topographic variables, only in September did those improvements lie outside of the 95 % confidence interval. With nine times finer spatial resolution and more frequent image collection, our SF maps characterize intra-annual dynamics of smaller water bodies (<30 m wide) and mesic vegetation integral to ecosystem functioning in semi-arid systems compared to leading Landsat-derived products. Further, our workflow is easily reproducible using freely available data on an open access platform, and can be adopted to help guide land use decisions related to water resources by farmers, ranchers, and conservationists in semi-arid environments.

Hydrologic restoration of anthropoentically altered springs in the Sheldon National Wildlife Refuge in the Great Basin, USA

Springbox capped springs divert water for livestock and threaten spring conservation in the Great Basin. Springbox restoration is used to increase water availability at riparian zones and wet meadows. The purpose of our study was to compare six restoration methods used to increase soil moisture. We used a BACI design to compare percent soil moisture before and after restoration at 24 spring sites in Northwestern Nevada, U.S.A. Percent soil moisture was measured at 5-, 15-, 30-, and 45-cm depths during spring and summer months. Year 2017 was wetter than 2016 causing an increase in percent soil moisture in all restoration treatments. Empty springbox cases, cases filled with sand, and caseless gravel-filled springs produced the greatest increase in percent soil moisture at all depths. We recommend sand-filled casings because these funnel water to the surface while sand prevents casing collapse. We recommend sand over gravel because sand is easier to displace as water flows to the surface. The ratio of δ18O/d16O suggests that springs are fed by shallow groundwater derived from recent precipitation. Inter-annual reductions in precipitation driven by climate change may be the ultimate force determining the preservation of Great Basin spring ecosystems.

Linear scaling – negative effects of invasive Spiraea tomentosa (Rosaceae) on wetland plants and pollinator communities

Invasive plants directly and indirectly disrupt the ecosystem functioning, of which indirect effects, for example, through trophic cascades, are particularly difficult to predict. It is frequently assumed that the impact of an invading species on the ecosystem is proportional (linearly related) to its density or abundance in a habitat, but this assumption has rarely been tested. We hypothesised that abundance and richness of plants and potentially pollinators of wet meadows change as a result of invasion of steeplebush Spiraea tomentosa and that these changes are proportional to the density of the shrub. We selected 27 sites amongst wet meadows habitats invaded by S. tomentosa with coverage ranging from 0% to 100% and examined the diversity of plants, as well as the abundance and diversity of flower visitors (bees, butterflies with moths and flies). Our results showed that the richness of plants, as well as the richness and number of individuals of flower visitors, decrease significantly and linearly with an increase of the S. tomentosa cover. This finding supports the hypothesis that the impact of an invasive species can be proportional to their population density, especially if this species is limiting the available resources without supplying others. Our study is the first to show such an unequivocal negative, linear effect of an invasive shrub on the abundance and richness of potential pollinators. It proves that the negative impact of S. tomentosa on the wetland ecosystem appears even with a minor coverage of the invader, which should be taken into account when planning activities aimed at controlling the population of this transformer species. The simultaneously detected linear dependence allows us to assume that the benefits of controlling secondary populations of the shrub can be proportional to the incurred effort.

Is Grazing Good for Wet Meadows? Vegetation Changes Caused by White-Backed Cattle

Wetland ecosystems are highly productive and valued for numerous reasons including wildlife habitat, biodiversity, water quantity and quality, and human uses. Grazing livestock on wet grasslands can sometimes be controversial due the humidity of the habitat, but on the other hand, it plays an important role in grassland preservation. Therefore, we evaluated the impact of Polish white-backed cattle grazing on changes in the vegetation (13 phytosociological relevés taken in years 2016–2019) of wet meadows as well as forage quality based on the species composition. Biodiversity was estimated based on species richness, Shannon–Wiener diversity and evenness indices, and Rényi diversity profiles. The peatland featured mostly high-sedge and wet meadows communities of the Magnocaricion and the Calthion alliances. The species and biodiversity indices demonstrated significant rising trends. Extensive grazing resulted in the decreased cover of the dominant species of rush meadows, e.g., the common reed, acute, and tufted sedge. The gaps that had emerged thanks to the reduced cover of the dominant species were filled by meadow plants, which led to increased biodiversity. During the four years of grazing, the cattle obtained satisfactory weight gains, particularly in 2019, which indicates that wet meadows are suitable for grazing and can provide sufficient feed for cattle.

Ecosystems of Alas Landscapes—The Basis for the Development of Cattle Breeding in the Harsh Natural and Climatic Conditions of the Permafrost Zone

Alas landscapes are unique ecosystems, which are dynamic, geochemically closed thermokarst landforms of the permafrost zone. Alases have a limited capacity in their active layer, and specific conditions for soil, flora and fauna formation. A comprehensive study of alas landscape functionswas carried out in Central Yakutia from 1988 to the present time using conventional methods of geobotany, zoology, entomology, etc. This paper presents long-term observations of lake fluctuation cycles and changes in the spatial structure of meadow spaces. The dynamics of the spatial structure lead to significant fluctuations in the productivity of alas phytocenoses. It was revealed that wet and normal alas meadows have the highest vegetation productivity. The long-term course of their productivity tends to decrease, which shows the influence of anthropogenic pressure since the main haymaking areas are located in these meadows. With sharp fluctuations in interannual weather conditions, which determine the microclimatic and soil characteristics of grass growth, the productivity of the edge phytocenoses tends to increase. The productivity of the steppe phytocenoses of the alas remains practically at the same level. Over the years of observation, the economic capacity of alas pastures and hayfields was calculated. Additionally, the paper presents the important role of fauna within closed alas ecosystems, which directly affects the functioning of alas landscapes and is directly involved in soil formation and the circulation of matter and energy.

CUCUJUS CINNABERINUS (SCOPOLI, 1774) (COLEOPTERA: CUCUJIDAE) IN ROSCI0045 CORIDORUL JIULUI, ROMANIA

The protection of the Natura 2000 species Cucujus cinnaberinus (Scopoli, 1774), protected by Romanian and European legislation, requires knowledge of distribution, threats and conservation status. In Romania the species is protected in only 9 Natura 2000 areas of the 442 SCI declared until 2021. All the protected areas in which the species is mentioned are located along the Carpathian Arch except ROSCI0135 Pădurea Bârnova – Repedea located in the Central Moldavian Plateau. The identification of the species in ROSCI0045 Coridorul Jiului brings new data about the distribution of the species and its conservation status. Observations on the species in larval stage were made by direct searches in specific habitats in the protected area. In the months of May, August and September 2022, Cucujus cinnaberinus was identified in several points along the protected area: Dăbuleni on poplar wood in the Danube River meadow, Foișor on poplar wood in the Jiului meadow, Bratovoești in ploplar wood of the former channels of the meanders Jiului River, Calopăr on ash wood from the Dâlga valley and Turburea on alder wood in the Gilortului meadow. The identification of Cucujus cinnaberinus Natura 2000 species requires further monitoring at the site and the implementation of appropriate protection and conservation measures.

Effects of grazing versus mowing on the vegetation of wet grasslands in the northern Pre‐Alps, Switzerland

AbstractQuestionWet grasslands are among the most threatened habitats in Central Europe and are subject to loss of their unique species assemblages. Grazing and mowing are important conservation management tools for such semi‐natural habitats. The aim of this study was to investigate and compare the influence of grazing and mowing on the diversity and species composition of wet grassland vegetation.LocationMontane wet grasslands in the Gantrisch Nature Park, Switzerland.MethodsWe sampled 18 pairs of vegetation plots along land‐use borders between grazing and mowing (fence‐line contrasts), distributed over six fens, mostly belonging to the phytosociological alliance Calthion palustris. We tested for differences in structural parameters, biodiversity indices, mean ecological indicator values and the frequency of individual species. In addition, a detrended correspondence analysis was carried out.ResultsManagement type had no influence on species richness, Shannon index or Shannon evenness. Maximum microrelief, vegetation height, mean nutrient indicator value and mean competitive strategy were significantly higher with grazing, whereas the mean aeration indicator value and the mean ruderal strategy were significantly higher with mowing. Cirsium oleraceum, Filipendula ulmaria, Geum rivale and Juncus effusus, species of nutrient‐rich wet meadows, were more frequent under grazing, whereas mowing favoured grassland species with wide ecological amplitude, such as Plantago lanceolata and Trifolium pratense.ConclusionsAt the plot scale, vascular plant diversity did not differ between these management regimes. Thus, from the conservation point of view, in the study region, there is no clear preference for either management type, and both should be eligible for subsidies. At the landscape scale, it is beneficial to have both management types present to ensure high gamma‐diversity, as they favour different species.

Growing the state endemic, Oregon semaphoregrass (Pleuropogon oregonus)

Oregon semaphoregrass (<i>Pleuropogon oregonus</i> Chase [Poaceae]) is a rare grass that occurs in only a handful of locations in eastern Oregon montane wet meadows, primarily on private lands. Propagation and outplanting methods have been developed over the past few decades to expand the geographic extent and to increase the number of plants by introductions in protected areas. The species rapidly increases through rhizomatous growth in a range of environmental conditions, provided sufficient moisture and nutrients are present, but is susceptible to some pests and pathogens. Over 2 decades, introductions with vegetative material have survived and increased in a mid-elevation meadow on Burns Paiute Tribal lands, a site relatively far from natural populations. Introductions in other areas have largely failed, however, likely because of unsuitable site environmental characteristics. Lessons learned from the successful propagation and outplanting program on Burns Paiute Tribal lands may be useful in future introductions, provided necessary site environmental attributes are identified. Copeland SM, Crouch CG, Palmer BJ, Hamerlynck EP, Ziegenhagen LL, Brown J. 2023. Growing the state endemic, Oregon semaphoregrass (<i>Pleuropogon oregonus</i>): focus on a successful propagation and introduction program on Burns Paiute Tribal lands. Native Plants Journal 24(1):62–71.

Effects of extreme rainfall frequency on soil organic carbon fractions and carbon pool in a wet meadow on the Qinghai-Tibet Plateau

The frequent occurrence of extreme rainfall events may greatly affect soil organic carbon (SOC) fractions and carbon (C) pool of wet meadow in the Qinghai-Tibet Plateau (QTP). However, it remains unclear how SOC fractions will change under different extreme rainfall frequency. Therefore, we set five extreme rainfall frequency treatments in the QTP wet meadow: CK (control plots), DF1 (once a week), DF2 (once every-two weeks), DF3 (once every-three weeks), DF4 (once every-four weeks), all treatments received ambient rainfall. We found that soil particulate organic carbon (POC) content increased with the increasing of extreme rainfall frequency in 0–40 cm layer. Extreme rainfall frequency significantly decreased dissolved organic carbon (DOC) content in 0–10 cm layer. DF2, DF3 and DF4 significantly decreased the soil easily oxidizable carbon (EOC) content, DF2 significantly increased and DF4 significantly decreased SOC content in 0–10 cm layer. Soil organic carbon storage (SOCS) decreased with the increase of extreme rainfall frequency, the lowest value in DF1 treatment (85.61 mg·hm−2) and the highest value in DF4 treatment (139.92 mg·hm−2). The EOC/SOC and DOC/SOC values at 20–40 cm were greater than those at 0–10 cm under each treatment, and the proportion of SOC fractions in the surface layer (0–10 cm) was more sensitive to the extreme rainfall frequency, while in the deep soil layer (10–20, 20–40 cm) was relatively stable. Redundancy analysis (RDA) showed that soil bulk density (BD) (Explanation = 31.8 %), total phosphorus (TP) (Explanation = 12.8 %), NH4+-N (Explanation = 8.8 %) were important environmental factors affecting the SOC fractions content under extreme rainfall frequency. Our study suggests that the increase of extreme rainfall frequency in the future will lead to significant differences in the content of SOC fractions and will reduce the SOCS by affecting soil physicochemical properties, and this may have a serious impact on the C sequestration function and C pool stability of QTP wet meadow soil.

Cambios recientes en la estructura paisajística del humedal de batuco, Chile Central

In spite of the copious regulations created in the last years to protect the Batuco wetland, located in Lampa county; at the northeast of the Metropolitan Region, Chile, this ecosystem has not stopped suffering a significant degradation, expressed by the modification of its landscape. In this study we evaluated the temporal change experienced in the last decades by the landscape structure of that wetland as a result of such degradation. To do this, we calculated a set of landscape metrics over their main land use/land covers; interpreted and mapped from an aerial photograph acquired in 2005 and a satellite image acquired in 2021, in order to allow us to measure the magnitude of its temporary variations. The doubling of the urban area within the period of interest was manifested by their continuous and regular sprawl over mainly two natural vegetation land covers of the wetland: wet brackish meadows and open thorn scrublands. Both have great ecological significance for the ecosystem under consideration, being reduced to patches with smaller core area; clear evidence of a fragmentation process confirming the degradation propitiated by the recent anthropic occupation of the wetland’s soils. Through this research it is expect to provide to the scientific community and the competent government agencies, quantitative data contributing to diagnose the degradation of the wetland in question, so that they can more efficiently guide monitoring and management actions for their conservation and restoration.

Physiological response of adult Salix aurita in wetland vegetation affected by flooding with As-rich fine pyrite particles

An uncontrolled, natural episode of flooding with waters contaminated with As-rich pyrite (FeAsS) particles caused serious ecological damage leading to necrosis of plants growing in a fresh wet meadow located in an area characterized by unique geological structures rich in arsenopyrites. One of the few plant species capable of surviving this event was Salix aurita L., which grew in numbers in the analyzed area, but individual plants were affected differently by toxic flooding. No significant phenotypic changes (Group I), through partial leaf and/or stem necrosis (Group II) up to necrosis of the whole parental plant and root suckers (Group III), were observed for various willow clumps. These varied phenotypic responses of S. aurita to As-rich sediments were compared with the biochemical status of the foliage of willow trees, and with their rhizosphere physiological parameters.Our in situ study revealed that the biochemical status of leaves reflects the phenotypic damage incurred by adult willows growing in their natural environment and affected by the flooding. In leaves of willows with increasingly negative phenotypic changes (Groups I → II → III) as well as increasing levels of reactive oxygen species, malondialdehyde and decreased levels of glutathione and thiol groups were detected. Phytochelatins, commonly considered major As chelators, were not detected in S. aurita leaves. Despite a decrease in the size of leaves with the intensity of tree damage, all leaves expressed a normal level of leaf pigments.Phenotypic changes observed for particular willow clumps were only partly related to soil As levels. Moreover, As and S (but not Fe) foliar levels were related but did not correspond strictly with foliar biochemical features, or with soil As levels, soil pH or soil microbial activity, with the latter two drastically decreased in the rhizospheres of willows from Groups II and III.

The Orchids of Wetland Vegetation in the Central Balkans

Wetland ecosystems are important habitats for the growth and survival of numerous terrestrial orchids in Europe. This study reviews the current knowledge on the orchids of wetland vegetation in the Central Balkans. The orchid flora was analyzed from taxonomic, phytogeographical, ecological and conservation aspects. The most important taxa include the two Balkan endemics (Dactylorhiza cordigera subsp. bosniaca and D. kalopissi subsp. macedonica) and the three subendemics of the Balkans and the Carpathians (Dactylorhiza cordigera subsp. cordigera, D. maculata subsp. transsilvanica and Gymnadenia frivaldii), as well as a considerable number of Central European, Eurasian and boreal orchid representatives. Several orchid taxa occurring in the wet meadows and fens of the Central Balkans have a southern limit of their distribution in this part of Europe, suggesting that wetlands are important refuges for them. In total, 33 orchid taxa were recorded in plant communities from five classes, 10 orders and 17 alliances. Most orchid taxa grow in the following wetland vegetation types: wet meadows (class Molinio-Arrhenatheretea, order Molinietalia caeruleae, alliances Molinion caeruleae, Deschampsion cespitosae and Calthion palustris); fens (class Scheuchzerio palustris-Caricetea fuscae, order Caricetalia fuscae, alliance Caricion fuscae); tall-herb vegetation along mountain streams and springs (class Mulgedio-Aconitetea); marshes and herb-land vegetation of freshwater or brackish water bodies (class Phragmito-Magnocaricetea). This study highlights the importance of serpentine and silicate wetland vegetation types as important habitats for the survival of terrestrial orchids. In addition, detailed taxonomic, ecological and chorological studies of the wetland orchids of the Central Balkans need to be carried out in order to establish a successful plan for their conservation.

Mammals of Hazeldell Nature Preserve, Pulaski County, Kentucky: A Rare Highland Rim Ecosystem

Hazeldell Nature Preserve is a rare ecosystem on the Highland Rim of south-central Kentucky. It is the only state-protected site of its kind. This preserve is comprised of two distinct plant communities, including wet flatwoods and wet meadow. Despite its uniqueness, no ecological studies have been conducted on mammals in the past. Currently, two separate studies are underway on mammals. Here we present the results from the first of these that used camera traps set in the wet flatwoods community from 1 February to 28 March 2020. A total of 34,071 photos were taken with 553 having images of 12 species of mammals. The four most photographed species were eastern gray squirrel, Virginia opossum, white-footed deermouse, and white-tailed deer. These four species appeared in 91% of photos. The remaining 49 photos were of eight species including: eastern cottontail, coyote, bobcat, northern raccoon, striped skunk, southern flying squirrel, common gray fox, and eastern fox squirrel. Woodchuck and eastern chipmunk were not photographed during the study, yet each have ranges that include the preserve. These burrowers may avoid the preserve because of the secondary water table and saturated soil that occur during extended periods. The results of this study serve as baseline data for comparison to future camera trapping. Continued photo documentation will be used to identify changes in the mammal species composition of the preserve caused by species range changes in response to various factors, including habitat fragmentation and climate change.

СОДЕРЖАНИЕ РТУТИ В ПОЧВЕННЫХ БЕСПОЗВОНОЧНЫХ РЕКРЕАЦИОННОЙ ЗОНЫ КРУПНОГО ПРОМЫШЛЕННОГО ГОРОДА (Г. ЧЕРЕПОВЕЦ)

Soil invertebrates are the main food resource for birds and small mammals. The migration of mercury into the food webs of terrestrial ecosystems is still poorly investigated. The mercury content in soil, earthworms, wolf spiders and harvesters of the forest park zone of Cherepovets (Vologda region) was determined. The collection of the material was carried out on 5 sites (birch-aspen forest, wet pine forest, dry pine forest, wet meadow, dry meadow) differing in the composition of vegetation and the position in the cascade of geochemical landscapes. The minimum mercury content was found in the soils of the dry meadow (eluvial landscape) – 25 ng/g, the maximum – in the soils of the wet meadow (accumulative landscape) – 188 ng/g. The maximum concentrations of mercury in all sites were found in earthworms – from 261 ng/g in the dry pine forest to 1095 ng/g in the wet meadow. The concentration of mercury in wolf spiders was lower than in earthworms. The minimum values were found in a dry meadow. In all sites, the mercury content in wolf spiders was significantly higher than in harvesters. There are no significant correlations between the mercury content in soils and the organism of the studied invertebrates.

The interaction between large mammals and Acheulean tools during the Middle Pleistocene in the Manzanares valley (Madrid, Spain): new evidence for Santa Elena and Oxígeno sites

The fluvial deposits of the Manzanares and Jarama rivers present one of the largest concentrations of lithic and faunal remains of Pleistocene sites in Europe. In the Manzanares River close to the confluence of the Jarama River, the stepped terrace system disappears and gives way to the Complex Terrace of Butarque (CTB), where the sites of Santa Elena and Oxígeno are located. Different numerical dates obtained from the visible CTB’s bottom suggest that it was deposited during the MIS 6 or even MIS 7. This paper provides the first taphonomic and palaeoecological interpretation of both collections. A total of 445 fossil elements have been recorded in Oxígeno. The most represented are cranial fragments of Elephas sp. About Santa Elena, 130 fossil elements have been recorded. The best represented are fragments of Bos/Bison sp. horns and Elephas sp. tusks. The taphonomic processes identified at both sites bring to light a complex taphonomic history. The incidence of processes related to fluvial transport is higher in Oxígeno than in Santa Elena. Besides, dismemberment cut marks have been identified exclusively on the humerus of Bos primigenius in Santa Elena. Several tooth marks from carnivores have been recorded: small pits and scores at Oxígeno as well as pits and furrowing on Bos primigenius and Megaloceros sp. bones from Santa Elena. The faunal association depict an open landscape of wet meadows with herbaceous vegetation adjacent to riparian wood habitats associated with the Manzanares alluvial plain, where hominids and predators competed to some unknown extent.

Temporal and geographic extent of the late Holocene dry period in the central Great Basin, USA

We provide evidence from pollen and radiocarbon dating of wet meadow sediments for the presence of multi-centennial drought, termed the Late Holocene Dry Period (LHDP), in the central Great Basin between 3100 and 1800 cal yr BP. We examine four sites along a south to north transect between 39° N and 42° N latitude, spanning the boundary of the anti-phasing dipole pattern of precipitation associated with ENSO. The LHDP conforms to the dipole pattern but contains three different phases, an initial 900-year dry period, followed by 200 years of wetter climate and then another 200 years of extreme drought. The dipole boundary appears to have shifted to a new semi-stable position with each period. Between 3100 and 2200 cal yr BP, the boundary seems to conform to the 40° N parallel across central Nevada, and trending to 42° N in northwest Nevada. Between 2200 and 2000 cal yr BP the boundary shifted south of 40° N, when all sites predominantly record wet conditions. Between 2000 and 1800 cal yr BP the boundary shifts north to ∼41° N, representing the driest phase which was widespread across central Nevada. A review of lake levels, tree-rings, and submerged stumps suggest that the drought between 2000 and 1800 cal yr BP was of greater magnitude than that recorded during the MCA megadrought. We do not yet have sufficient information to establish a cause for megadroughts, however it is important to note that the climate system periodically locks into a pattern with a consistently northward shifted storm track that persists for multiple decades to centuries, bringing persistent drought to the American Southwest. Indigenous human societies adapted to severe droughts through a variety of responses, suggesting a pattern of resilience and mobility in response to recurring climate change across the Great Basin.

Effects of historical management on the vegetation and habitat properties of wet meadows in Germany

Wet meadows in Germany are of high conservational value with a strong decline over the last centuries. Occasionally, new meadows developed, providing us with the opportunity to compare vegetation and habitat properties of wet meadows with currently similar, but different historical management. We categorized the areas as ancient, old or young, according to the point of establishment and grassland continuity in the last two centuries. Several trends derived from other grassland types proved also to be true for wet meadows like a high diversity of vascular plants and Red List species in long‐term managed grasslands. Old grasslands, established one to two centuries ago, exhibited the highest diversity of vascular plants and bryophytes, indicating additional plants arrived by seeding. We investigated species composition using ordination and indicator species. Ancient grasslands were characterized by plants adapted to wet meadows (Molinietalia) such as Rhinanthus serotinus. Young meadows were marked by plants revealing succession like Carex brizoides or a high productivity. A trend, contrary to other grassland types, was that most habitat properties exhibited no temporal pattern except habitat area and few soil attributes. Altogether, a stepwise intensification from ancient to young meadows was detected that reflects the fast development from traditional to modern agriculture. Including the grassland's history in conservation approaches and adapting the management accordingly will improve restoration attempts. Ancient and old grasslands provided more appropriate species for future wet meadows, whereas young grasslands often need a more intensive land use and would benefit from seeding to develop to species‐rich meadows.

Extensive archaeobotanical data estimate carrying capacity, duration, and land use of the Late Bronze Age settlement site Březnice (Czech Republic)

The reconstruction of the settlement´s hinterland and acquisition of plant resources is one of the crucial questions in the field of environmental archaeology. Our study is focused on the reconstruction of the settlement’s structure and character of the environment from which the site drew resources. These research questions were addressed by the interpretation of plant macroremains, charcoals, and the results of the spatial model. We have focused on the maximum size of the settlement that the surrounding countryside was able to withstand. Our results clearly demonstrated significant deforestation and intensive land use in the vicinity of the Late Bronze Age study site. As the weed taxa showed, a wide range of crops was grown in rather dry or less often in damp fields. Based on our archaeobotanical results, we were able to reconstruct several types of grasslands: dry pastures and fallow fields on plateaus and slopes, wet pastures or meadows in the floodplain. Acidophilous oak forests, alluvial forests, and shrubs were reconstructed as the most common forest habitats in the vicinity of the study site. Based on the archaeological knowledge of the region, we assume relatively low population density during the Late Bronze Age, and thus only a small part of the more or less forested landscape was significantly affected by human activities.