Lowland Grassland Research Articles

Status and distribution of the globally threatened Bristled Grassbird Chaetornis striata (Jerdon, 1841) (Fam. Sylviidae) in Nepal

Lowland grasslands in Nepal were thoroughly surveyed in 1996-1999 to assess the status and distribution of the globally threatened Bristled Grassbird Chaetornis striata. Birds were located on foot, from elephants and from jeeps by sight and sound backed up by mistnets and tape playback. The status information was updated again by visiting these areas in 2010-2012. Bristled Grassbirds were recorded in Sukla Phanta and Koshi Tappu Wildlife Reserves, and Chitwan National Park where most of the Nepal population is confined. From the research, it was found that they were most associated with newly formed Saccharum and Imperata dominated grasslands during summer. The low numbers present during winter suggested that this species was primarily a summer migrant to Nepal. A total population for Nepal is presented based on a reliable density estimate. Loss and degradation of grassland habitat and invasion of Mikania micrantha were identified as the major threats. Further research on migratory status, better control of cattle grazing inside reserves, expansion of Protected Areas to include more grassland, and listing of Bristled Grassbird as protected under the wildlife law of Nepal for its conservation are highly recommended. DOI: http://dx.doi.org/10.3126/init.v5i0.10244 The Initiation 2013 Vol.5; 1-15

The impact of extreme summer drought on the short-term carbon coupling of photosynthesis to soil CO<sub>2</sub> efflux in a temperate grassland

Abstract. Along with predicted climate change, increased risks for summer drought are projected for Central Europe. However, large knowledge gaps exist in terms of how drought events influence the short-term ecosystem carbon cycle. Here, we present results from 13CO2 pulse labeling experiments at an intensively managed lowland grassland in Switzerland. We investigated the effect of extreme summer drought on the short-term coupling of freshly assimilated photosynthates in shoots to roots as well as to soil CO2 efflux. Summer drought was simulated using rainout shelters during two field seasons (2010 and 2011). Soil CO2 efflux and its isotopic composition were measured with custom-built chambers coupled to a quantum cascade laser spectrometer (QCLAS-ISO, Aerodyne Research Inc., MA, USA). During the 90 min pulse labeling experiments, we added 99.9 atom % 13CO2 to the grass sward. In addition to the isotopic analysis of soil CO2 efflux, this label was traced over 31 days into bulk shoots, roots and soil. Drought reduced the incorporation of recently fixed carbon into the shoots, but increased the relative allocation of fresh assimilates below ground compared to the control grasslands. Contrary to our hypothesis, we did not find a change of allocation speed in response to drought. Although drought clearly reduced soil CO2 efflux rates, about 75% of total tracer uptake in control plots was lost via soil CO2 efflux during 19 days after pulse labeling, compared to only about 60% under drought conditions. Thus, the short-term coupling of above- and below-ground processes was reduced in response to summer drought. The occurrence of a natural spring drought in 2011 lead to comparable albeit weaker drought responses increasing the confidence in the generalizability of our findings.

Methane emissions from beef and dairy cattle: Quantifying the effect of physiological stage and diet characteristics1

The prediction of methane outputs from ruminant livestock data at farm, national, and global scales is a vital part of greenhouse gas calculations. The objectives of this work were to quantify the effect of physiological stage (lactating or nonlactating) on predicting methane (CH4) outputs and to illustrate the potential improvement for a beef farming system of using more specific mathematical models to predict CH4 from cattle at different physiological stages and fed different diet types. A meta-analysis was performed on 211 treatment means from 38 studies where CH4, intake, animal, and feed characteristics had been recorded. Additional information such as type of enterprise, diet type, physiological stage, CH4 measurement technique, intake restriction, and CH4 reduction treatment application from these studies were used as classificatory factors. A series of equations for different physiological stages and diet types based on DMI or GE intake explained 96% of the variation in observed CH4 outputs (P<0.001). Resulting models were validated with an independent dataset of 172 treatment means from 20 studies. To illustrate the scale of improvement on predicted CH4 outputs from the current whole-farm prediction approach (Intergovernmental Panel on Climate Change [IPCC]), equations developed in the present study (NewEqs) were compared with the IPCC equation {CH4 (g/d)=[(GEI×Ym)×1,000]/55.65}, in which GEI is GE intake and Ym is the CH4 emission factor, in calculating CH4 outputs from 4 diverse beef systems. Observed BW and BW change data from cows with calves at side grazing either hill or lowland grassland, cows and overwintering calves and finishing steers fed contrasting diets were used to predict energy requirements, intake, and CH4 outputs. Compared with using this IPCC equation, NewEqs predicted up to 26% lower CH4 on average from individual lactating grazing cows. At the herd level, differences between equation estimates from 10 to 17% were observed in total annual accumulated CH4 when applied to the 4 diverse beef production systems. Overall, despite the small number of animals used it was demonstrated that there is a biological impact of using more specific CH4 prediction equations. Based on this approach, farm and national carbon budgets will be more accurate, contributing to reduced uncertainty in assessing mitigation options at farm and national level.

Contrasting response of grassland versus forest carbon and water fluxes to spring drought in Switzerland

Since the European summer heat wave of 2003, considerable attention has been paid to the impacts of exceptional weather events on terrestrial ecosystems. While our understanding of the effects of summer drought on ecosystem carbon and water vapour fluxes has recently advanced, the effects of spring drought remain unclear. In Switzerland, spring 2011 (March–May) was the warmest and among the driest since the beginning of meteorological measurements. This study synthesizes Swiss FluxNet data from three grassland and two forest ecosystems to investigate the effects of this spring drought. Across all sites, spring phenological development was 11 days earlier in 2011 compared to the mean of 2000–2011. Soil moisture related reductions of gross primary productivity (GPP) were found at the lowland grassland sites, where productivity did not recover following grass cuts. In contrast, spring GPP was enhanced at the montane grassland and both forests (mixed deciduous and evergreen). Evapotranspiration (ET) was reduced in forests, which also substantially increased their water-use efficiency (WUE) during spring drought, but not in grasslands. These contrasting responses to spring drought of grasslands compared to forests reflect different adaptive strategies between vegetation types, highly relevant to biosphere–atmosphere feedbacks in the climate system.

Seasonal Variation in Habitat Selection by Free-Ranging Feral Horses Within Alberta’s Forest Reserve

Little is known about habitat selection by free-ranging feral horses in Montane environments, including how horse use may vary seasonally throughout the year. We tracked four global positioning system collared horses in four separate harems between November 2008 and October 2010 for a portion of the Rocky Mountain Forest Reserve in southwest Alberta, Canada. We assessed seasonal habitat selection for the study period by combining locational data with landscape data (including vegetation types) in an information theoretic framework. Home ranges for horses varied from 12.4 to 90km2 and were confined to local watersheds. Horses selected most for lowland grasslands across all seasons, with shrublands increasingly selected in spring and summer. Harvested conifer forests were only selected by horses during winter. Resource selection functions indicated that in addition to vegetation type, horses were selecting for a variety of habitat characteristics (i.e., distance to forest and solar radiation), while water availability, topographic accessibility, and disturbance features (e.g., distance to roads, recreational trails, and seismic lines associated with energy exploration) had little or no influence on horse selection. Overall, horses demonstrated selection for habitats covering 14% of the study area while avoiding 42% of habitats: remaining areas were used in proportion to their availability. Concentration of horse use within sparse vegetation types (grassland and shrubland), particularly during one or more times of the year, help identify critical horse habitat including areas where multiple, overlapping land uses interact on public land.

Cattle habitat selection and associated habitat characteristics under free-range grazing within heterogeneous Montane rangelands of Alberta

The integration of multiple uses on public rangeland requires reliable information on patterns of livestock use. We used GPS data and field plot utilization indices to examine cattle selection at the landscape and patch levels, respectively, within a heterogeneous Montane environment of SW Alberta, Canada. We also evaluated factors associated with patterns of summer cattle use, including topographic features, distance to water and roads, as well as forage quantity and quality. Cattle preferred lowland and upland grasslands, while avoiding conifer forests and clear cuts. Selection patterns differed markedly between the landscape and plot scales. At the landscape scale, forage use was related to abiotic factors, primarily slope (β=−0.70) but also distance to water (−0.34) and distance from roads (+0.21). The negative impact of slope was greater than that observed in previous studies, and has implications for identifying primary ranges and deriving sustainable carrying capacities in Montane landscapes. At the plot (feeding patch) scale, forage use was additionally related to biomass availability (β=+0.58), and to a lesser extent crude protein concentration (+0.16), highlighting the importance of forage characteristics in regulating cattle use. Lowland grasslands had the highest biomass and received the greatest forage use (43% utilization). Low visitation (44% of plots) and associated forage use (3% herbage utilization) by cattle within cut blocks, combined with conservative forage use across all habitats (3–43%), indicate grazing by cattle is consistent with maintaining other uses within this area, including riparian function, native grassland conservation and forest management.

The importance of disturbance for the conservation of a low-competitive herb in mesotrophic grasslands

For the protection or re-establishment of species-rich grasslands, the limiting factors controlling species richness have increasingly become of scientific interest. This study aims to analyze the role of disturbance for the occurrence of a low-competitive herb, Centaurium erythraea Rafn, in mesotrophic, lowland grasslands in NW Germany. We sampled a total of 38 plots with presence of C. erythraea and 24 control (random) plots in semi-natural grasslands. As a proxy for disturbance, we estimated the cover of bare ground and Ellenberg flooding indicator species and measured the distance between the plot and the nearest path. Moreover, we counted the number of C. erythraea individuals within each plot. In the GLM analyses the distance from path was the only predictor; both the presence of the species and the number of individuals decreased with the distance from path. The grasslands at the path edges had the highest disturbance intensity. Here horse riding, military-vehicle traffic and regular sod-cutting directly create bare ground. In general, disturbance creating bare ground seems to be the key factor enabling germination and growth of C. erythraea in mesotrophic grasslands and other low-competitive short-lived species. Disturbance enhances the expression of the seed bank, favours the development of the shade-avoiding and low-growing rosettes and oppresses tall-growing competitors. Therefore we suggest grazing as the best management method.

Shrubs versus ‘gullivers’: woody species coping with disturbance in grasslands

Resprouting of trees and shrubs in forest-grassland ecotones is a key process to understand the dynamics of these systems under different disturbance regimes. This study integrates resprouting of grassland shrubs and pioneer forest trees (‘gullivers’), burned in subtropical lowland grassland and cut in temperate highland grassland of Rio Grande do Sul, Brazil. Per grassland site, 20 individuals each of 1–2 grassland shrub species (Asteraceae) and two forest tree species (Myrsinaceae, Myrtaceae) were tagged, and post-disturbance survival and growth monitored for 1 year at 2–4 month intervals. Differences in resprouting vigour (summed-up basal area of resprouted shoots per pre-disturbance summed-up area of basal stems), and in density and allometry of resprouted shoots (allocation mode) were compared between tree and shrub species by linear mixed effects modelling and multiple comparisons, using the Tukey test. All grassland shrub individuals resprouted and regained 73–142 % (species average) of pre-disturbance basal area within one year, as opposed to 14–24 % in trees. All Myrtaceae ‘gullivers’ resprouted, but up to two-thirds of Myrsine individuals did not survive disturbance. Tree species tended to produce either many slender or few stout shoots, while shrub species were intermediate between these extremes. Forest trees regained 22–46 % of pre-disturbance height, independent of allocation mode, and grassland shrubs up to 73 %. This suggests that grassland fires allow grassland shrubs but not forest trees to persist and to grow to reproductive size. Differing sprout allocation modes may reflect allometric constraints rather than strategies to outgrow the fire-prone grass matrix.

Rodent diversity and habitat use in a protected area of Buenos Aires province, Argentina

Habitat use of rodents is associated to environmental variables, species requirements and biological interactions. The aim of this study was to analyse the macro and microhabitat use and spatial variation in the abundance of small sylvan rodents that inhabit Otamendi Natural Reserve, Argentina. We studied rodent communities in six habitats: riparian forest, Celtis tala forest, lowland grassland, salt marsh and two highland grasslands. We captured a total of 153 individual of Scapteromys aquaticus Thomas 1920, Akodon azarae Fischer 1829, Oxymycterus rufus Fischer 1814, Oligoryzomys flavescens Waterhouse 1837, Deltamys kempi Thomas 1917 and O. nigripes Olfers 1818 with a trapping effort of 3636 trap-nights. The species richness is maintained by the presence of different habitats that satisfy specific requirements from specialist species to more generalist species using differentially the reserve and forming communities of different specific composition in each habitat. A differential macrohabitat use by all species and a certain level of selectivity at microhabitat scale in individuals of two species were observed. This study shown that the diversity of environments of a Natural Reserves allows the maintenance of many sylvan species of small rodents; confirming the high ecological and conservational value of the reserves inside an urban region.

Effects of artificially varying amounts of rainfall on two semi‐natural grassland types

AbstractQuestionIs a lowland grassland community with a lower amount of ambient precipitation and a high abundance of subdominant species more sensitive to altered rainfall input in comparison with mountain grassland with higher ambient precipitation and a low abundance of subdominant species?Location(1) Lowland Festuca grassland characterized by dry acidophilous vegetation, low mean annual precipitation and high species richness, and (2) mountain Nardus grassland with high mean annual precipitation and low species richness in the Eastern Czech Republic.MethodsWe conducted a manipulative experiment with rainout shelters and gravity irrigation systems. We simulated three levels of precipitation input (50%, 100% and 150%) and examined the treatment effects on above‐ground net primary productivity (ANPP) of the main plant functional groups (grasses, forbs, legumes, shrubs and mosses) and on plant species composition over three consecutive years.ResultsAltered rainfall input had a significant effect on total live ANPP in the drier, lowland grassland community, while no pronounced effect was observed in the mountain grassland characterized by higher ambient precipitation. In the lowland grassland, changes in total ANPP resulted primarily from enhanced growth of subdominant non‐N‐fixing forbs in response to the direct effect of higher artificial rainfall input and an indirect effect of reduced competition with grasses in drier treatments.ConclusionsWetter, species‐poor mountain grasslands will probably show smaller changes in response to expected climate changes in ANPP, species number and abundance than lowland grasslands, characterized by dry acidophilous vegetation, with higher species richness and higher abundance of subordinate species.

An economic assessment of drought effects on three grassland systems in Switzerland

This paper analyzes the economic impacts of summer drought on Swiss grassland production. We combine field trial data from drought experiments in three different grasslands in Switzerland with site-specific information on economic costs and benefits. The analysis focuses on the economic implications of drought effects on grassland yields as well as grassland composition. In agreement with earlier studies, we found rather heterogeneous yield effects of drought on Swiss grassland systems, with significantly reduced yields as a response to drought at the lowland and sub-alpine sites, but increased yields at the wetter pre-alpine site. Relative yield losses were highest at the sub-alpine site (with annual yield losses of up to 37 %). However, because income from grassland production at extensive sites relies to a large extent on ecological direct payments, even large yield losses had only limited implications in terms of relative profit reductions. In contrast, negative drought impacts at the most productive, intensively managed lowland site were dominant, with average annual drought-induced profit margin reductions of about 28 %. This is furthermore emphasized if analyzing the farm level perspective of drought impacts. Combining site-specific effects at the farm level, we found that in particular farms with high shares of lowland grassland sites suffer from summer droughts in terms of farm-level fodder production and profit margins. Moreover, our results showed that the higher competitiveness of weeds (broad-leaved dock) under drought conditions will require increasing attention on weed control measures in future grassland production systems. Taking into account that the risk of drought occurrence is expected to increase in the coming years, additional instruments to cope with drought risks in fodder production and finally farmers’ income have to be developed.

Quantifying changes in flooding and habitats in the Tonle Sap Lake (Cambodia) caused by water infrastructure development and climate change in the Mekong Basin

The economic value of the Tonle Sap Lake Floodplain to Cambodia is arguably among the highest provided to a nation by a single ecosystem around the world. Nonetheless, the Mekong River Basin is changing rapidly due to accelerating water infrastructure development (hydropower, irrigation, flood control, and water supply) and climate change, bringing considerable modifications to the flood pulse of the Tonle Sap Lake in the foreseeable future. This paper presents research conducted to determine how the historical flooding regime, together with human action, influenced landscape patterns of habitats in the Tonle Sap Lake, and how these habitats might shift as a result of hydrological changes. Maps of water depth, annual flood duration, and flood frequency were created for recent historical hydrological conditions and for simulated future scenarios of water infrastructure development and climate change. Relationships were then established between the historical flood maps and land cover, and these were subsequently applied to assess potential changes to habitat cover in future decades. Five habitat groups were clearly distinguishable based on flood regime, physiognomic patterns, and human activity: (1) Open water, flooded for 12 months in an average hydrological year; (2) Gallery forest, with flood duration of 9 months annually; (3) Seasonally flooded habitats, flooded 5–8 months and dominated by shrublands and grasslands; (4) transitional habitats, flooded 1–5 months and dominated by abandoned agricultural fields, receding rice/floating rice, and lowland grasslands; and (5) Rainfed habitats, flooded up to 1 month and consisting mainly of wet season rice fields and village crops. It was found that water infrastructure development could increase the area of open water (+18 to +21%) and the area of rainfed habitats (+10 to +14%), while reducing the area covered with seasonally flooded habitats (−13 to −22%) and gallery forest (−75 to −83%). Habitat cover shifts as a result of climate change include a net increase of open water (2–21%), as well as a reduction of rainfed habitats by 2–5% and seasonally flooded habitats by 5–11%. Findings from this study will help guide on-going and future conservation and restoration efforts throughout this unique and critical ecosystem.

Identification of Black-tailed Godwit’s Limosa limosa breeding habitat by botanical and environmental indicators

Despite concentrated conservation efforts and targeted agri-environmental schemes, breeding wader species have declined in most western European countries during recent decades. Assuming that wader species aggregate in relation to physical and biological features of their breeding habitats, this study aimed to identify botanical and environmental indicators that can be used to identify sites and management regimes to enhance breeding potential for the Black-tailed Godwit Limosa limosa as a focal species. We selected 36 fields (mean 7.1 ha) with and without this species in grazed lowland grasslands in the Danish Wadden Sea area. Bird numbers observed during 2007 and 2008 were analysed in relation to environmental and management variables together with presence/absence of plant species in the main body of the fields, the field silt trenches and field edges. Black-tailed Godwits preferred unfertilized fields with a short growth plant community that included the presence of moss-carpet. The plant indicator species for fields with Black-tailed Godwit were besides Bryopsida (moss sp.) also Trifolium pratense var. maritimum (maritime red clover), Poa trivialis (rough meadowgrass), Plantago major (greater plantain) and Veronica serpyllifolia (thyme-leaved speedwell).

Improving the Farmland Biodiversity Value of Riparian Buffer Strips: Conflicts and Compromises

The intensity of management of lowland grassland fields in the United Kingdom, coupled with the fact that such grasslands dominate much of the lowland landscape, means that there are now few opportunities for many plants, invertebrates, birds, or mammals to survive. The Scottish Agricultural College (SAC) has investigated whether fencing off the margins of such fields next to watercourses to control diffuse pollution has any positive impacts on biodiversity, based on assessments of vegetation composition and condition and structure of assemblages of invertebrates of importance as foodstuffs to farmland birds. Fencing watercourses increased the abundance of key groups of invertebrates. However, the invertebrate species diversity was not increased unless the margins were ≥ 5.4 m in width. Margins established in the study area to prevent access by livestock to watercourses or to enhance biodiversity are generally ≤ 2.6 m wide and are therefore unlikely to provide conditions for additional invertebrate species to use. The dense, tall swards within such margins are also unlikely to provide foraging opportunities for farmland birds. Management (such as low-intensity grazing by livestock in the margins) is essential to provide the conditions required for these groups, but this could conflict with the diffuse pollution mitigation aims. A compromise is proposed whereby limited autumn/winter grazing by livestock could be used to open the vegetation structure in the margins. Grazing by livestock at that time may be acceptable since it is not occurring in the period of main diffuse pollution concern (i.e., the fecal contamination of watercourses and bathing waters in the spring and summer). It is also essential that a landscape-scale approach is taken, driven by knowledge of the full needs of the species concerned, when deciding where best to target agri-environmental actions aimed at farmland bird conservation.

The effects of submergence on anatomical, morphological and biomass allocation responses of tropical grasses Chloris gayana and Panicum coloratum at seedling stage

Submergence is a major factor affecting seedling recruitment in lowland grassland ecosystems. Our aim was to evaluate the tolerance to increasing flooding intensity of the seedlings of tropical grasses Chloris gayana K. and Panicum coloratum L., whose use as a forage species is increasing in humid grasslands. For this purpose, 2-week-old seedlings of C. gayana and P. coloratum were subjected to control, partial submergence (PS) and complete submergence (CS) in clear water for 14 days and allowed to grow for a subsequent 12-day period to assess their recovery. The following responses were assessed: generation of root aerenchyma, morphological changes and emergence from water, biomass allocation in relation to plant size, and biomass accumulation. Results showed that constitutive root aerenchyma was high in both species. Under PS and CS, root aerenchyma increased by up to 50–55% in C. gayana and up to 40–48% in P. coloratum. Under PS, the increase in seedling height for both species was the same as for controls. Under CS, C. gayana further increased its height and emerged more quickly from water; P. coloratum was not able to increase its height, and therefore the seedlings always remained underwater. The escape-from-water response of C. gayana was associated with preferential biomass allocation towards shoots and with a marked lengthening of leaf blades. By contrast, there was no change in allocation in P. coloratum, and its leaves were shorter under CS. The final biomass of C. gayana under CS was similar to that under PS, and equivalent to 54% of its controls. In P. coloratum, biomass under PS and CS were 64 and 21% of its controls (respectively), which indicates that injury caused by CS persisted during the post-submergence period. In conclusion, both species are tolerant to PS at the seedling stage. However, when flood depth increases by submerging the seedlings, C. gayana is able to escape from water while P. coloratum is not, thus strongly affecting its recovery. Therefore, C. gayana appears to be a more promising species for cultivation in lowland grasslands prone to flooding of unpredictable intensity.

ANALISIS TATA RUANG (ZONASI) PENGEMBANGAN EKOWISATA DI KAWASAN TAMAN NASIONAL BALURAN JAWA TIMUR

Research on potential ecotourism development at Baluran National Park which consists more than 25.000 Hectares area and coast line about 42 km long has been conducted from June to September 2003 in the local communities area around Baluran National Park and 5 ecosystems type such as mangrove forest, lowland tropical forest, deciduous forest, evergreen forest, and grassland. The objectives of this study were to definited the zonation for ecotourism. For these, research was initiated to inventory ecotourism supply such are biophysic attractions, socio culture local people attractions, tour object around Baluran National Park and facilities attractions. In order to obtain data and information for ecotourism demand of tourist and local people characteristic included activity, interest and opinion data were collected through questionnaires and open-ended interviews. The collected data were analyzed by using zonation analysis for ecotorism landscape. Based on the zonation analysis revealed that at Baluran National park obtained 3 zonation that could further develop for ecotourism: (1) mangrove and coral reef ecotourism zonation, (2) savana and forest ecotourism zonation, (3) village ecotourism zonation. Kind of attraction for ecotourism on each zonation are biodiversity of flora and fauna, coral reef, etnobotany information and cultural local people activities.

The short term agronomic impact of raising canal water levels in grassland areas: A case study in the Belgian polders

This study tested the hypothesis that raising canal water levels with 30 cm beyond the growing season in intensively managed lowland grassland (2.4–3.7 m above sea level) in Belgium decreases the agronomic value of pastures The study ran 3 years before and 3 years after the water elevation. Using five pairs of plots inside and outside the wetted perimeter, it was not possible to demonstrate significant impacts of the elevated water level on dry matter yield, forage quality, botanical composition, and penetration resistance of the top soil layer of the grassland. In an ex situ lysimeter experiment, simulating the effect of a water level in canals up to 50 cm beneath the surface of the pastures indicated a significant decrease of the penetration resistance of the top soil layer. Results are discussed and confronted with the difficulties of field research addressing the elevation of water levels.

Using multi-scale modelling to predict habitat suitability for species of conservation concern: The grey long-eared bat as a case study

Although spatial scale is important for understanding ecological processes and guiding conservation planning, studies combining a range of scales are rare. Habitat suitability modelling has been used traditionally to study broad-scale patterns of species distribution but can also be applied to address conservation needs at finer scales. We studied the ability of presence-only species distribution modelling to predict patterns of habitat selection at broad and fine spatial scales for one of the rarest mammals in the UK, the grey long-eared bat (Plecotus austriacus). Models were constructed with Maxent using broad-scale distribution data from across the UK (excluding Northern Ireland) and fine-scale radio-tracking data from bats at one colony. Fine-scale model predictions were evaluated with radio-tracking locations from bats from a distant colony, and compared with results of traditional radio-tracking data analysis methods (compositional analysis of habitat selection). Broad-scale models indicated that winter temperature, summer precipitation and land cover were the most important variables limiting the distribution of the grey long-eared bat in the UK. Fine-scale models predicted that proximity to unimproved grasslands and distance to suburban areas determine foraging habitat suitability around maternity colonies, while compositional analysis also identified unimproved grasslands as the most preferred foraging habitat type. This strong association with unimproved lowland grasslands highlights the potential importance of changes in agricultural practices in the past century for wildlife conservation. Hence, multi-scale models offer an important tool for identifying conservation requirements at the fine landscape level that can guide national-level conservation management practices.

Hantavirus ecology in rodent populations in three protected areas of Argentina

In this study, we identified hantavirus genotypes and their reservoirs and evaluated the spatial and temporal distribution of the virus in rodent population in three protected areas of Argentina over 3 years (2007-2010). A total of 837 rodents were captured with an effort of 22 117 trap-nights. We detected the genotype Lechiguanas in Oligoryzomys nigripes and O. flavescens and Pergamino in Akodon azarae. There was no correlation between seroprevalence and trap success of the host. The proportion of seropositive males was significantly higher than the proportion of seropositive females. The total length of seropositives was higher than that of seronegatives in each host species. Seropositive individuals were observed in warm months and not in cold months, which suggests an infection cycle. This investigation confirms that protected areas of central east Argentina are places with a variety of sylvan rodents species associated with different hantavirus genotypes where reservoirs are numerically dominant. Although there was more than one known reservoir of hantavirus, only one species had antibodies in each area. This can be explained because the transmission of the virus does need not only the presence of a rodent species but also a threshold density. Longevity of even a small proportion of the host population in cold months may provide a trans-seasonal mechanism for virus persistence. The seroprevalence detected was higher than the one found before in rodent populations of Argentina, and this explains the appearance of human cases in two of these three areas.

Trampling enhances the dominance of graminoids over forbs in flooded grassland mesocosms

AbstractQuestions: What are the interactive effects of flooding and cattle tramplingupon the structural attributes and the floristic composition of a plant commu-nity? Do the effects on the plant community persist over an extended recoveryperiod?Location: Flooding Pampa grasslands, Argentina (36 130 0 S, 58 0 W).Methods: We assessed the effects of 40-d of flooding, trampling and thecombination thereof on plant cover and biomass, vertical distribution of foliageand floristic composition in lowland grassland mesocosms. We considered a120-d recovery period to evaluate the persistence of flooding and tramplingeffects on the plant community.Results: Flooding, with or without trampling, increased cover and biomass ofthe graminoid species, especially marsh grasses, which developed a tallercanopy, whereas most of the forb species were negatively affected. This wasenhanced by trampling, as the aerial biomass of the dominant legume Lotustenuisdecreasedby90%,whilethreemajorforbspeciesdisappeared.Tramplingunder flooding conditions did not reduce the total above-ground biomassproduction, as the growth enhancement of graminoids was enough to com-pensate for the breakdown of the forbs. Below-ground biomass was lowerwhen both perturbations occurred simultaneously. After 120-d of recovery,graminoids continued to be dominant while the remaining forbs (including L.tenuis) recovered only partially. Below-ground biomass recovered fully at theend of the growing season.Conclusions: The combination of flooding and trampling shifts the communityco-dominance of graminoids and forbs towards a persistent dominance ofgraminoid species. When both perturbations are combined, the above-groundproduction of the grassland is unaffected and root biomass is rapidly recovered.However, the loss of the legume L. tenuis deserves attention because this is theunique nitrogen-fixing species of the ecosystem, which improves the foragequality for livestock production.IntroductionTrampling and flooding are two major co-occurring per-turbationsinmanyhumidgrasslandecosystemssubjectedto livestock grazing (Soriano 1991; Milchunas & Lauen-roth 1993; Kohler et al. 2004; Altesor et al. 2006). Thoseperturbationsexertantagonisticeffectsuponthestructur-al attributes and the floristic composition of the plantcommunity.Tramplingmodifiesthecommunitystructureby flattening out the vertical distribution of the canopy(Edmond 1964; Pellerin et al. 2006; Van Uytvanck et al.2010), and changes the floristic composition by favouringprostrate stoloniferous graminoids and rosette forbs (Salaet al. 1986; Sun & Liddle 1993; Cole 1995a; Kobayashietal.1997).Incontrast,floodingmodifiesthecommunitystructure by promoting the location of foliage in upperlayers of the canopy (Pehrsson 1988; Insausti et al. 1999;Striker et al. 2005) and subordinating species with rosetteand creeping growth forms, which remain mostly sub-merged and shaded during the flooding period (Insaustietal.1999;VanUytvancketal.2010).Todate,theeffectsof