Agri-environment schemes and butterflies: the utilisation of 6 m grass margins

The utilisation of 6 m countryside stewardship scheme (CSS) grass margins by butterflies was studied at two farms in Essex between 1997 and 2000. The aim of the study was to establish whether grass margins in cereal fields, as set up and managed under CSS guidelines, would be beneficial to common farmland butterflies. Eight 6 m grass margins (total length 3492 m) and two control sections (no margin; total length 700 m) were monitored over the first years of the agreements using the transect method. Significantly greater total numbers of butterflies and individuals of Maniola jurtina were seen on the 6 m grass margins than on the control sections. There was a significant increase in abundance of Maniola jurtina on the margins over the 4-year study period. Significantly more butterflies and Maniola jurtina were seen on the sown 6 m grass margin next to set-aside than on any of the other methods of establishment. Sown next to set-aside was best for Pyronia tithonus, but not significant.     

Butterfly habitats, broad-scale biotope affiliations, and structural exploitation of vegetation at finer scales: the matrix revisited

Abstract. 1. Biotope and resources data are rarely attached to arthropod (butterfly) synoptic monitoring systems, and invariably not linked to behavioural exploitation of vegetation substrates. Yet, these data allow us to examine resource use within different biotopes and to distinguish more clearly between habitat and the matrix. 2. Comparative data on vegetation exploitation for different behaviours (search flight, direct flight, tactile inspections, perching, feeding, interactions, oviposition) were collected using transect sections over a range of biotopes from bare ground to mature woodland for two closely related satyrine butterflies, Maniola jurtina and Pyronia tithonus with overlapping flight times. Occupancy data were obtained on Pararge aegeria as a marker for the woodland end of the biotope spectrum. 3. There were clear distinctions in biotope occupancy between M. jurtina (grassland bias) and P. tithonus (shrub bias); significant differences in exploitation of vegetation substrates (except for nectar feeding) coincided with this bias in transect sections which comprise both grassland and shrubs. The exception (nectar feeding) is explained by the decline in shrub (Rubus fruticosus) nectar and increase in herb nectar during the later emergence of P. tithonus. 4. Direct flight increased in unsuitable biotopes for both species. However, resource‐exploiting behaviour (>70%) predominated even in biotopes that would be regarded as completely unsuitable for supporting the species and where less than 2% of individuals for each species were observed. 5. Simultaneous collection of biotope, resources, and behavioural data is needed for monitoring affinities of butterflies to vegetation structures and using butterflies as indicators of environmental changes. 6. Much of the landscape is shown to comprise valuable resources for butterflies, even when classified for metapopulation studies as empty matrix.     

The influence of chalk grasslands on butterfly phenology and ecology

The influence of large‐scale variables such as climate change on phenology has received a great deal of research attention. However, local environmental factors also play a key role in determining the timing of species life cycles. Using the meadow brown butterfly Maniola jurtina as an example, we investigate how a specific habitat type, lowland calcareous grassland, can affect the timing of flight dates. Although protracted flight periods have previously been reported in populations on chalk grassland sites in the south of England, no attempt has yet been made to quantify this at a national level, or to assess links with population genetics and drought tolerance. Using data from 539 sites across the UK, these differences in phenology are quantified, and M. jurtina phenology is found to be strongly associated with both site geology and topography, independent of levels of abundance. Further investigation into aspects of M. jurtina ecology at a subset of sites finds no genetic structuring or drought tolerance associated with these same site conditions.     

Grassland Butterfly Fauna under Traditional Animal Husbandry: Contrasts in Diversity in Mown Meadows and Grazed Pastures

Semi-natural grasslands resulting from traditional land use practices (mowing and grazing) are severely endangered throughout Europe due to the intensification of agriculture. The ecological impact of mowing and grazing on grassland butterflies was studied in eight mown meadows and eight grazed pastures under traditional animal husbandry in NW Russia and adjacent Finland. Transect count data over 3 years (1997–1999) covered a total of 48 species and 5742 individuals. The butterfly fauna was rather similar under both management forms; species richness, diversity and total abundance did not differ significantly between meadows and pastures, yet meadows were preferred by more species. In both groups, the most abundant species were Aphantopus hyperantus, Pieris napi and Thymelicus lineola. Of 37 species observed as a minimum of five individuals, Polyommatus amandus, Ochlodes sylvanus and A. hyperantus showed a significant preference for mowing management. According to the ordination, butterfly communities were affected more by the origin and age of the grassland than the present management method. Landscape factors (meadow or pasture surrounded by forests or open environments), the abundance of nectar plants and the intensity of tilling were the most important factors differentiating older grasslands from the younger ones evolved from old Finnish hay fields cultivated prior to the 1940s.     

Interrelations Among Habitat Use, Behavior, and Flight-Related Morphology in Two Cooccurring Satyrine Butterflies, Maniola jurtina and Pyronia tithonus

Mobility, activity patterns, habitat use, and some morphological traits of two often cooccurring satyrine butterflies of grasslands—the meadow brown (Maniola jurtina) and the hedge brown (Pyronia tithonus)—were studied by a mark-release-recapture method at two sites. Additionally, someflight-related morphological traits of a series of collected females of P. tithonus were compared between recently colonized and permanent populations. The more active, but less mobile P. tithonus got faster wing damage than did M. jurtina and had more, and more symmetrically spread eyespots onthe wings. For both species, the microdistribution was affected by shelter, long vegetation, and nectar, but this was more pronounced in P. tithonus. It is hypothesized that P. tithonus may traverse the same landscape at a slower rate than M. jurtina.     

What Prolongs a Butterfly's Life?: Trade-Offs between Dormancy,Fecundity and Body Size

In butterflies, life span often increases only at the expense of fecundity. Prolonged life span, on the other hand, provides more opportunities for oviposition. Here, we studied the association between life span and summer dormancy in two closely related species of Palearctic Meadow Brown butterflies, the endemic Maniola nurag and the widespread M. jurtina, from two climatic provenances, a Mediterranean and a Central European site, and tested the relationships between longevity, body size and fecundity. We experimentally induced summer dormancy and hence prolonged the butterflies’ life in order to study the effects of such a prolonged life. We were able to modulate longevity only in Mediterranean females by rearing them under summer photoperiodic conditions (light 16 h : dark 8 h), thereby more than doubling their natural life span, to up to 246 days. Central European individuals kept their natural average live span under all treatments, as did Mediterranean individuals under autumn treatment (light 11: dark 13). Body size only had a significant effect in the smaller species, M. nurag, where it affected the duration of dormancy and lifetime fecundity. In the larger species, M. jurtina, a prolonged adult life span did, surprisingly, not convey any fecundity loss. In M. nurag, which generally deposited fewer eggs, extended life had a fecundity cost. We conclude that Mediterranen M. jurtina butterflies have an extraordinary plasticity in aging which allows them to extend life span in response to adverse environmental conditions and relieve the time limitation on egg-laying while maintaining egg production at equal levels.     

Diversification of mowing regime increases arthropods diversity in species-poor cultural hay meadows

Agricultural intensification reduces the biodiversity of European farmlands. Hay meadows represent an important farmland habitat, traditionally used to produce hay. With decreased demand for hay, the continuation of hay harvest is supported by Agri-environmental schemes across European Union. Modern hay harvest techniques differ from traditional manual harvest by removing the grass instantaneously over large land areas. To minimize adverse effects on meadow invertebrates, diversifying harvest operations is time and space is often recommended, but effects of such diversification are little studied. We compared the impact of uniform hay harvests with harvests executed in patchy manners, using four arthropod groups (butterflies, ground beetles, orthopterans and spiders) at productive, species-poor meadows in the Czech Republic. Butterflies, observed along transects, avoided uniformly cut units, preferring those cut as strips or blocks. In the three remaining groups, recorded using pitfall traps, a majority of species prevailed in traps located in uncut conditions. Synchronous mowing of large areas suppresses population sizes and diminishes the diversity of common arthropods. Besides of direct mortality and depletion of such resources as nectar or shelter, it synchronises sward regrowth, threatening also species requiring short-sward patches. Uniformly executed mowing contradicts the biodiversity conservation goal of Agri-environmental schemes. Diversifying the mowing operations via temporary fallows, or sequential mowing of land units, will improve the situation for common cultural meadows.     

Does microclimate affect grasshopper populations after cutting of hay in improved grassland?

The microclimate of an improved hay meadow was studied using Tinytag dataloggers to record sward temperature after cutting. Temperatures in the sward were then compared to grasshopper abundances to see if mowing created an excessively hot microclimate unfavourable for sustained grasshopper activity in mid summer. The abundance of Chorthippus albomarginatus and Chorthippus parallelus was significantly reduced on the hay plots compared to the unmanaged control swards, which may have been due to high sward temperatures created by the absence of tall, shady vegetation in which grasshoppers may take refuge to avoid overheating. This study suggests that a combination of mortality caused by the physical process of mowing, and high sward temperatures created by removal of the standing crop by cutting may cause the low abundance of grasshoppers in improved grassland in eastern England. This research is particularly important when considering the orthopteran assemblages of Environmental Stewardship Scheme field margins where mowing for hay in July and August may seriously reduce grasshopper populations. If mowing of grassland has to occur during the grasshopper season, we suggest a later cut in September or a system of rotational mowing, leaving areas of uncut grassland as shelter.     

Effect of local weather on butterfly flight behaviour,movement, and colonization: significance for dispersal under climate change

Recent climate change is recognized as a main cause of shifts in geographical distributions of species. The impacts of climate change may be aggravated by habitat fragmentation, causing regional or large scale extinctions. However, we propose that climate change also may diminish the effects of fragmentation by enhancing flight behaviour and dispersal of ectothermic species like butterflies. We show that under weather conditions associated with anticipated climate change, behavioural components of dispersal of butterflies are enhanced, and colonization frequencies increase. In a field study, we recorded flight behaviour and mobility of four butterfly species: two habitat generalists (Coenonympha pamphilus; Maniola jurtina) and two specialists (Melitaea athalia; Plebejus argus), under different weather conditions. Flying bout duration generally increased with temperature and decreased with cloudiness. Proportion of time spent flying decreased with cloudiness. Net displacement generally increased with temperature. When butterflies fly longer, start flying more readily and fly over longer distances, we expect dispersal propensity to increase. Monitoring data showed that colonization frequencies moreover increased with temperature and radiation and decreased with cloudiness. Increased dispersal propensity at local scale might therefore lower the impact of habitat fragmentation on the distribution at a regional scale. Synergetic effects of climate change and habitat fragmentation on population dynamics and species distributions might therefore appear to be more complex than previously assumed.     

Habitat and host plant use of the Large Copper Butterfly Lycaena dispar in an urban environment

The Large Copper (Lycaena dispar) has been extensively studied due to its high conservation priority. The species has declined severely in North-West Europe, but is currently expanding in Central and North-East Europe. In this study, we investigated egg deposition patterns at three different spatial scales (site, plant, and leaf level) for L. dispar at 23 sites within the municipality of Vienna (Austria). In one season, a total of 2,457 eggs were counted on six Rumex species, of which two (R. stenophyllus, R. patientia) represent novel host plant records. Rumex crispus harboured 87.6% of all egg counts and was significantly preferred (4.4 eggs per plant) over the second-ranked R. obtusifolius for oviposition (1.1 eggs per plant). At the habitat scale, eggs were observed at all study sites. Egg numbers per site were equal across landscape zones, including stretches of waste land in urban habitats, except for lower egg numbers on meadows at the margin of the Vienna forest. Mowing was negatively related to the number of eggs found on all three studied scales. We conclude that L. dispar eggs are easier to find compared to adult butterflies, the butterfly can utilize more host plant species than what was previously known, and that mowing has a strong negative influence on the local butterfly populations. Urban wastelands provide important habitats, in which the species can sustain substantial population densities which are in comparison to those in the countryside. Conservation action should focus on applying less intensive rotational mowing, preferably involving mowing of suitable sites every 2?years.     

No detrimental effects of delayed mowing or uncut grass refuges on plant and bryophyte community structure and phytomass production in low-intensity hay meadows

To maintain European semi-natural grasslands, agri-environment schemes (AES) have been established in many countries but their biodiversity benefits have remained limited. We tested the effects of three new mowing regimes designed to benefit biodiversity in extensively managed meadows across the Swiss lowlands. Our experimental treatments mimicked easily implementable farming practices. We previously showed that invertebrates benefit from delayed mowing and leaving an uncut grass refuge. Here we focus on the effects on plant and bryophyte communities.We compared the standard AES practice (earliest mowing on June 15, no fertilizer input, but no restriction on number of cuts) to three alternative mowing regimes: (i) earliest mowing delayed by one month, (ii) maximum of two cuts per year with at least eight weeks in between, and (iii) leaving an uncut refuge on 10–20% of the meadow area in 12 study areas in the Swiss lowlands. We also tested for the interactive effects of ambient temperature, precipitation, elevation, meadow size, local forest cover, time since AES registration, and phytomass production.After five years of application, we found no difference in the effects of mowing regimes on vascular plant or bryophyte species richness, community composition, phytomass, flowering phenology or average plant height (the latter two indices were derived from the literature). However, cutting frequency and hay nutritional quality (C:N and Ca:P ratios) were lower under delayed mowing. Vascular plant and bryophyte species richness as well as forage quality were negatively related to phytomass, while the latter was positively related to mean summer temperature and negatively to time since AES registration.We conclude that supporting invertebrate biodiversity with alternative mowing regimes has no detrimental effects on the vascular plants and mosses, while the reduced forage quality calls for additional financial compensation of the farmers adopting these agri-environment schemes.     

Unmown refuge areas and their influence on the survival of grassland birds in the Saône valley (France)

The objective of this study is to assess the attractiveness of refuge areas to the avifauna of the mown prairies in the Val de Saône region, after the disappearance of all cover by mowing. We compared the densities of several species, notably the corncrake, Crex crex, and the common quail, Coturnix corturnix, in three categories of refuge areas of unmown grasslands. Within the 10-m wide strips, covering in total 3–5% of the study area, bird densities at the beginning of August, after the hay-making season, are much higher than the densities recorded in the prairies during haymaking in July. Quail and corncrake densities are always lower, although still higher than the July densities in the prairie, in the fields of some 0.5 ha (covering 6.1% of another study area). In fields of 1 ha or more, the low densities of the two species reveal their poor attractiveness, or the absence of it. When during outside-in mowing some 10-m wide strips in the center of the fields are left uncut before the completion of mowing, or when during inside-out mowing two 5-m wide strips along the field margins are not mown, the contacts between the mowing machine and half of the unfledged young quails, and one-third of the unfledged young corncrakes, can be avoided.     

Grazing hay meadows: History,distribution, and ecological context

Aims

Once widely used across Europe, grazing of hay meadows is now a rare agricultural practice that is mainly applied in rural regions with maintained traditional agriculture. In this review, we examine the knowledge on grazing hay meadows in the Carpathian Mountains, including its historical distribution, implementation and timing, potential impacts on grassland productivity and biodiversity, and implications for grassland conservation and restoration.

Location

The Carpathian Mountains (43.8–50.1°N, 16.9–27.1°E).

Methods

We conducted a literature review including biological, ecological, agricultural, ethnological, and historical sources.

Results and Conclusions

In each of the seven farming systems that existed in parallel in the Carpathian Mountains before agricultural intensification, grazing of hay meadows was applied regularly. Spring, autumn, and occasionally summer grazing, along with corralling and manuring of hay meadows, were integral parts of these systems, adapted to the seasonal movement of dairy farms across various agroecosystems. The data reviewed provide insight into the role of animals in hay meadow management, as well as how the breakdown of these historical farming systems is impacting local biodiversity, the economy, and the community. According to the literature sources, grazing hay meadows has numerous positive impacts on grassland biodiversity, including suppressing fast-growing competitors, reducing the accumulation of litter, increasing the availability of germination gaps, dispersing seeds through zoochory, supporting ground-nesting birds through later mowing, and promoting the regeneration of plants from seeds. From this perspective, the combination of mowing and grazing can be considered a promising tool in current grassland conservation and restoration efforts.     

Butterfly abundance in a warming climate: patterns in space and time are not congruent

We present a model of butterfly abundance on transects in England. The model indicates a significant role for climate, but the direction of association is counter to expectation: butterfly population density is higher on sites with a cooler climate. However, the effect is highly heterogeneous, with one in five species displaying a net positive association. We use this model to project the population-level effects of climate warming for the year 2080, using a medium emissions scenario. The results suggest that most populations and species will decline markedly, but that the total number of butterflies will increase as communities become dominated by a few common species. In particular, Maniola jurtina is predicted to make up nearly half of all butterflies on UK Butterfly Monitoring Scheme (UKBMS) transects by 2080. These results contradict the accepted wisdom that most insect populations will grow as the climate becomes warmer. Indeed, our predictions contrast strongly with those derived from inter-annual variation in abundance, emphasizing that we lack a mechanistic understanding about the factors driving butterfly population dynamics over large spatial and temporal scales. Our study underscores the difficulty of predicting future population trends and reveals the naivety of simple space-for-time substitutions, which our projections share with species distribution modelling.     

Evaluating alternative mowing regimes for conservation management of Central European mesic hay meadows: A field experiment

Conservation status of hay meadows highly depends on their management. The main goal of this study was to assess the efficiency of different mowing regimes in maintenance of plant species richness and diversity of mesic hay meadows. The field experiment was carried out on a species rich, mesic hay meadow in Western Hungary. We evaluated the effects of four alternative types of management on the plant community after 7 years of continuous treatment: (1) mowing twice a year, typical traditional management, (2) mowing once a year in May, most practised currently by local farmers, (3) mowing once a year in September, often proposed for conservation management and (4) abandonment of mowing. Traditional mowing resulted in significantly higher number and higher diversity of vascular plant species than other mowing regimes. Mowing twice a year was the only efficient way to control the spread of the invasive Solidago gigantea, and mowing in September was more successful in it than mowing in May. We conclude that the traditional mowing regime is the most suitable to maintain botanical diversity of mesic hay meadows; however, other regimes should also be considered if certain priority species are targeted by conservation.     

An experimental examination of the effects of habitat quality on the dispersal and local abundance of the butterfly Parnassius smintheus

Abstract 1. Nectar flower abundance was manipulated through flower removal, and sex ratio was manipulated by moving individual butterflies within a series of nine alpine meadows. The movement and abundance of the butterfly Parnassius smintheus in the meadows were monitored using mark–release–recapture methods.
2. A total of 937 butterflies, 698 males and 239 females, was captured. There were 223 observed between-meadow movements. Fifty-two per cent of males and 35% of females moved among meadows.
3. The immigration of male butterflies was related positively to nectar flowers, host plant abundance, and female butterflies. Male emigration was not affected by any of the treatments. The number of males captured was related positively to nectar flowers and host plants but not affected by sex ratio. The number of resident male butterflies was greater in meadows containing flowers and was related positively to host plant abundance, but unaffected by sex ratio.
4. Flower removal, sex ratio, and abundance of Sedum had no significant effect on the abundance, movement, or residence time for female butterflies, in part due to small sample size.
5. The fact that males immigrate to higher quality meadows suggests that male butterflies are assessing meadow quality, either by sampling meadows or potentially from a distance using olfactory cues.     

Annual burning of semi‐natural grasslands for conservation: winners and losers among plant species

Species‐rich semi‐natural grasslands in Europe are a main target for conservation efforts, and alternative methods to the traditional management of mowing or grazing would be welcome due to the difficulties in maintaining traditional management practices. One such method proposed is burning of grassland vegetation during late winter or spring. To evaluate the effects of annual spring burning vs annual mowing on semi‐natural grassland vegetation, we compared the frequency of species in eleven field experiments in southern Sweden after ca 14 years. Out of the 88 species analyzed, five were more frequent in burnt plots compared with mowed plots (Vicia cracca, Cirsium arvense, Urtica dioica, Galium verum, Convallaria majalis). In contrast, 37 species were significantly less frequent in burnt plots compared with mowed ones, those with the largest differences being Ranunculus acris, Briza media, Veronica chamaedrys, Festuca ovina, Plantago lanceolata and Anthoxanthum odoratum. Tall‐grown species and those with preferences for N‐rich soils increased in frequency under an annual spring‐burn regime, compared with annual mowing, as did species producing larger amounts of nectar. Hence, although vegetation composition becomes more trivial with annual spring burns, there might be long‐term benefits for nectar‐feeding insects.     

Seasonal fluctuations in butterflies and nectar resources in a semi-natural grassland near Mt. Fuji, central Japan

We investigated seasonal fluctuation patterns in species and individuals of adult butterflies and flowering plants providing nectar in a semi-natural grassland in central Japan. We considered their interrelationships and implications for conservation. The semi-natural grassland included different vegetation structures and management regimes, including: (1) firebreaks where the grass was mowed and removed, (2) plantation areas that were mowed, (3) unpaved roads with mowed banks, (4) abandoned grassland, (5) scattered scrub forest, and (6) the surrounding forest. The sites with management (e.g., firebreaks), plantations and banks of the unpaved road sustained a larger number of butterflies and flowers than sites without management, such as the abandoned grassland, scrub forest and surrounding forest. The number of butterflies increased in the firebreak in June and at all sites in August and September. The firebreak sustained flowers in the spring, and the plantation area and banks of the unpaved road sustained flowers primarily in August and September, which was correlated with the distribution of butterflies. The different treatments such as mowing or mowing with removal of grass induced different numbers of flowers of each species affecting the habitat of adult butterflies through a season. On the other hand, the shrub tree species composing the scrub forest were host plants for the larvae of certain butterfly species. Our results suggest that heterogeneous environments with different human management or different vegetation structure or both could support habitat for various butterfly species, depending on the season and the seral stage.     

Mowing may bring about vegetation change,but its effect is strongly modified by hydrological factors

We assessed the effect of long-term (11 years) mowing with a hand scythe on the distributions of plant species and species turnover within meadow communities dominated by Carex acutiformis and C. acuta in a small lowland river valley subjected to annual flooding. We hypothesized that mowing would trigger the process of species exchange toward multispecies communities according to the abiotic environmental gradients, as has been reported for traditionally used wet meadows. We found that mowing had a much greater impact on the increase in plant species abundance in wetter, subjected to deeper and longer flooding, zone of the valley than in its drier part. The treatment and hydrology had no substantial effect on the sedges and cryptogams while the graminoids and the forbs were the least stable components of the plant communities. We found that annual management was conducive to the appearance of numerous seedlings of Alnus glutinosa in the part of wetland situated close to the valley edge. Surface flooding was found to be a driving force modifying the impact of mowing on sedge meadows. This “hydrological resetting impulse” created a specific floristic reset of the community, bringing it to the more simplified forms. Mowing every 4–5 years at the beginning of August is advisable to protect sedge meadows distributed in flooded small lowland river valleys.