Conservation value of road verges in the semi-arid Karoo, South Africa: ants (Hymenoptera: Formicidae) as bio-indicators

Ground-foraging ants (Hymenoptera: Formicidae) were used to assess the conservation value of road verges in a semi-arid region around Prince Albert, Western Cape Province, South Africa. Ant communities were sampled using pitfall traps on 50 sites along two roads. Four transects were sampled at each site, two in the road verge and two in adjacent rangeland. A total of 43,298 individual ants of 34 species were caught, with 31 and 32 species in the road verge and adjacent rangeland respectively, but on average road verges were the more species-rich. Road verges also contained relatively more rare species (i.e. those species that occurred in <10% of the traps. Ant species richness appeared to be influenced by food availability. Although ants appeared to be negatively impacted by higher grazing intensities in the rangeland, there was no difference in species richness between fenced and unfenced road verges. Species in the road verge may benefit directly from road kills, and indirectly from lower grazing pressure on plants, increased surface run-off and differences in soil surface temperatures. No alien ant species were observed or captured at any of the sites.     

Grazing impacts on the diversity and composition of alpine rangelands in Northwest Yunnan

Aims The eastern Himalayan region of Southwest China represents the world's most biodiverse temperate region as well as a cultural hotspot undergoing rapid cultural and ecological change. This area represents the center of origin for many plant groups including horticulturally valuable species of Pedicularis, Rhododendron and Primula. Alpine meadows here also provide summer pastures for Tibetan yak herders and the source for important medicinal plants. Stocking levels for livestock here have quadrupled over the last five decades and shrubs are encroaching into many historical rangelands. Yak herders voice concerns over both shrub encroachment and shrinking grasslands. In this study, we sought to determine: (i) Are alpine rangelands in Deqin County overgrazed and degraded? (ii) What are the local impacts of grazing on plant diversity and community composition? And (iii) which environmental variables covary with these differences in species composition across the grazing gradient?Methods To examine the ecological impacts of grazing in Deqin County, northwest Yunnan and assess its long-term sustainability, we used county records to determine historical population and livestock numbers, confirmed the results of interviews by Haynes (2011) and surveyed plant species richness and cover along a grazing gradient extending away from herder huts. Along these transects, we sampled 1?m 2 quadrats at 5 m intervals, noting species present and percent cover for vascular plants, grasses, sedges, rushes, moss, lichen, exposed rock, bare ground and feces. We also measured the average and maximum plant height within each quadrat. We then computed species richness for each of the 38 transects, calculating alpha and beta diversities. We used one-way ANOVAs to compare mean species richness values and average and maximum plant height across grazing intensities. To chart changes in composition along the 100m gradient, we also plotted the percent cover of graminoid, forb, shrub and bare ground versus distance from the hut. We applied NMS ordination to relate community patterns to environmental variables and grazing intensity using distances to determine species groupings.Important findings Livestock impacts are clearly evident with proportions of grass and bare ground decreasing, shrubs increasing and forbs maintaining even cover with increasing distance from the huts. In comparison with earlier surveys of sites farther from huts, we found reduced plant cover and diversity. Plant species richness almost doubles with increasing distance from herder huts from 9.9 to 19.3 species per 1 m 2 quadrat. An ordination of species and environmental variables demonstrates that grazing strongly affects plant community com position across these plots with strong impacts on palatable plants. If herd sizes remain large and suitable areas for grazing continue to decline, the cumulative impacts of grazing appear likely to degrade the rich diversity of the region and reduce rangeland quality, threatening its ability to sustain current grazing levels.     

A fence-line contrast reveals effects of heavy grazing on plant diversity and community composition in Namaqualand,South Africa

Changes in plant species richness and community composition were investigated across a fence separating heavily grazed communal and lightly grazed commercial farming systems in Namaqualand, South Africa. No significant differences in plant species richness between communal and commercial farming systems were detected either locally within individual plots or overall across all plots. Within-plot, richness of species tolerant of grazing, such as annuals and geophytes, has increased, while the richness of large palatable shrub species has decreased on the communal rangeland. In terms of plant cover, species' responses to grazing were strongly associated with growth form. Annuals and geophytes formed the majority of grazing increasers, while large, presumably palatable, shrubs and leaf succulents were characteristic grazing decreasers. An investigation into population processes of five shrub species revealed that heavy grazing on the communal rangeland has resulted in: reduced size of palatable shrub species; reduced flower production and seedling recruitment of palatable species; increased density and recruitment of the unpalatable shrub, Galenia africana. Reductions in shrub volume, reproductive output and seedling recruitment were most marked in the palatable shrub Osteospermum sinuatum and were in the order of 90%. The results are further discussed in terms of their relevance to rangeland dynamics and the current land use practices of the region.     

Effects of road age and distance on plant biodiversity: a case study in the Yellow River Delta of China

A majority of ecological studies of roads have usually focused on their deleterious effect, and these preconceptions have hampered a full evaluation of ecological functions of roads. We examined the effect of road disturbance on plant communities by investigating roadside vegetation in the protogenic road ecosystem of the Yellow River Delta (YRD), China. Specifically, we examined the effect of distance from the road verge and road age on the pattern of plant species richness, diversity, and composition at 17 sites. The results revealed that roads retained higher species richness adjacent to the road verge than far away from the road verge (>200 m). Additionally, species richness and diversity of roadside plants significantly decreased as the distance from the road verge increased. Plant species richness and diversity increased with road age in majority of prescribed distances, while species richness at the road verge significantly increased with road age and peaked at a road age of 20 years, after which species richness plateaued. A correspondence analysis illuminated that the roadside vegetation primarily consists of non-halophytic native species. The percentage of halophytes increased with the distance from the road verge and decreased with road age. Additionally, different performances of alien and native species in response to road disturbance were observed. Furthermore, it is worth noting that roadside environments provide survival habitats for some threatened species, such as wild soybean. In the present study, both positive and negative effects of roads on the plant community were observed from road construction to the long-term operational phases.     

Flowering and seed production success along roads with different mowing regimes

Question: Which one of the two mainly used mowing regimes along road verges, mowing once or twice a year is a better option regarding flowering and seed‐producing success of grassland species and plant species in general? Location: Southeast Finland. Methods: Plant species composition, flowering and seed production success were studied in road verges (1) mown once in August and (2) mown at the end of June and August. Flowering shoots were counted and phenological phases were estimated four times during a growing season. Results: The numbers of flowering or seed‐producing species and shoots indicated that mowing once a year corresponding to the timing of traditional management was markedly better than mowing twice a year. The difference between the management groups was greatest at the end of July when the number of flowering species was 43% and the number of flowering and seed‐producing shoots 76% less after the first mowing than in the still unmown sites. The species avoided early cutting either through the timing of flowering or due to their growth form. Early season mowing had no effect on the occurrence and seed‐producing success of grassland species and the first flowering species. Seed production of grasses succeeded poorly in the verges mown twice. Conclusion: Mowing once in August resulted in higher seed production in general, but mowing twice a season might be a better way to manage young verges on nutrient‐rich soils. The useful qualities of the management options should be considered locally when planning road verge management.     

Spatial analysis of anthropogenic disturbance regimes and roadside shrubs in a fragmented agricultural landscape

Abstract. In fragmented woodlands in agricultural regions of Australia, roadside environments (road verges) provide important refuges for threatened native fauna and isolated populations of plant species. However, as roads are transport corridors for humans and their vehicles, species survival is affected through destruction, fragmentation and modification of remaining habitat by human activity. Few studies have recognised the effects of anthropogenic disturbances, in the form of historical roadworks activities, on adjacent roadside plant populations. The aim of this study was to investigate the effects of soil disturbance from roadworks on the spatial patterns and structural dynamics of roadside Acacia populations in an agricultural area in southeastern Australia. Stem size and disturbance data were collected from 135 roadside populations of three species of Acacia shrubs in the Lockhart Shire area. Spatial pattern analysis using the Network K‐function and Discriminant Function analyses showed that road verge width, road category, disturbance intensity and distance to nearest town were highly significant variables in relation to disturbance from roadworks and shrub structural dynamics. Colonising populations were more abundant along gravel roads where soil disturbance intensity was high, whereas stable populations were more abundant where soil disturbance intensity was low. Senescent populations were more abundant in narrow, little used road verge corridors 4–6 km from nearby towns. These results suggest that anthropogenic disturbance regimes may be critical to shrub recruitment and persistence in roadside environments, which has important consequences for conservation of threatened native flora and fauna in agricultural landscapes.     

Hedges and Green Lanes: Vegetation Composition and Structure

In this paper the vegetation of 20 green lanes, defined as tracks bounded by hedgerows, is examined in terms of composition and structure and compared with that of 20 matched single hedgerows. For analysis the vegetation of the lanes was separated into three areas; central track, verges inside of hedgerows and verges outside of hedgerows. The vegetation of these areas was found to differ in species richness, community structure, plant strategies and environmental traits. When compared with verges of the matched single hedgerows, the inside verges and central track were greatly different whereas the outside verge appeared broadly similar. Green lanes contained significantly more plant species than matched single hedgerows, differences being most pronounced when compared as landscape units, rather than as a mean of the constituent parts. The potential effect of surrounding land use on green lane floral diversity is discussed as well as the importance of maintaining the structural diversity of green lanes for farmland biodiversity.     

Can grassland plant communities be preserved on road and railway verges?

Abstract. Semi‐natural grasslands are a threatened biotope type in many countries. Typical grassland plant species are adapted to continuous grazing or mowing that keeps the environment open. With the decline in grassland area, these species are ever more reliant on alternative habitats such as road verges. To find out whether plant communities comparable to those of semi‐natural grasslands can be maintained on modern road and railway sides, the vegetation of 92 grasslands and 90 road and railway verges was studied. These biotope types were compared with each other according to their community structure, total number of species, number of grassland species and restricted‐range diversity. Further study of the vegetation of road and railway verges was carried out in order to identify the treatments and environments which are most likely to support diverse plant communities. The species number and the restricted‐range diversity proved to be higher next to roads and railways than on grasslands. Grassland species were, however, most abundant on grasslands. Furthermore, the community structure of these biotope types was totally divergent. In their present state, road and railway verges are not a substitute for semi‐natural grasslands. Nevertheless, the occurrence of grassland species in verges may be enhanced by a suitable mowing regime, by giving up the use of de‐icing salt and herbicides and by allowing natural establishment of vegetation on the verges.     

Roadside habitats: effects on diversity and composition of plant, arthropod, and small mammal communities

Road edge effects cover extensive areas and exert a wide range of ecological influences on nearby plants and animals. Most studies have focused on individual and population level effects of the road edge; less is known about how communities and their functionality are altered in proximity to roads. Here, we studied the effect of road edges on species richness, rarity, endemism, composition, and functional (trophic) classification of communities of plants, ground-dwelling arthropods (beetles, spiders, scorpions, diplopods), and small mammals. The study, conducted in a Mediterranean ecosystem in central Israel, included sampling of these taxa in 10 plots adjacent to a regional road, and in 12 nearby control plots located in a typical shrubland habitat. We found a variety of community level road edge effects on the structure, composition, and function of the studied communities. The extent of effects varied among taxa, but they were generally positive or neutral. For the species-rich taxa (plants, beetles, and spiders), distinct road edge communities characterized by higher richness and altered species composition were found. Rarity and endemism were lower, and the proportion of disturbance-associated plant species was higher at the road edge. Among the species-poor taxa, scorpions and small mammals were more abundant along road edges than in control plots, while diplopods, the only negatively affected taxon, showed decreased abundance along the road. No ecologically meaningful changes in richness or composition were detected for the species-poor taxa along the road edge. Road edges profoundly affect floral and faunal communities, with possible implications for biodiversity conservation.     

Road-related landscape elements as a habitat: A main asset for small mammals in an intensive farming landscape

Road construction creates new habitats for a variety of species. In intensive farming landscapes, road verges may be the only suitable habitat for rodents. However, little attention has been paid to other road-related landscape elements (RRLEs), such as excavation slopes or the central islands of roundabouts, and their importance in a rodent territory. This study investigated all types of RRLE in terms of rodent abundances and habitat quality. RRLEs were compared with the semi-natural elements of the studied landscape using a capture-mark-recapture protocol. Four species and 3154 individuals were captured over a period of four months. Relative abundance and habitat quality were higher in RRLEs than in semi-natural elements. Mapping of the landscape showed that 86% of crop fields are accessible to Microtus arvalis (and almost 100% for Apodemus sylvaticus) from road verges. Our results highlight the importance of road verges and all other RRLEs in the conservation of species diversity in intensive farming landscapes.     

Effects of open grazing and livestock exclusion on floristic composition and diversity in natural ecosystem of Western Saudi Arabia

Livestock grazing is one of the main causes of rangeland degradation in Saudi Arabia. Fencing to exclude grazers is one of the main management practices used to restore vegetation and conserve biodiversity. The main objectives of this study were to investigate the changes in plant diversity and abundance, floristic composition and plant groups of the major life forms in response to thirty-five years of grazing exclosure in western Saudi Arabia. These vegetation attributes and palatability were compared in 30 sampling stands located in the excluded and grazed sites. Our results showed that livestock exclusion significantly increased covers, density and species richness of annuals, grasses, perennial forbs, shrubs and trees. Exclosure enhanced the abundance and richness of palatable species and depressed the development of weedy species. About 66.7% of the recorded species at the excluded site were highly palatable compared to 34.5% at the grazed site. In contrary, about 55.2% unpalatable species were found in the grazed site compared to 25.8% in the protected site. Jaccard’s similarity index between the excluded and grazed sites showed lower values of 0.39%, 0.40% and 0.31% at levels of families, genus and species, respectively. The results suggest that establishing livestock exclusion may be a useful sustainable management tool for vegetation restoration and conservation of plant diversity in degraded rangelands of arid regions.     

An underground index of rangeland degradation: cicadas in arid southern Africa

Summary The prediction that density of long-lived, underground herbivores (Cicadidae) is a function of rangeland condition was examined in arid shrublands in the Karoo, South Africa. It was found that the density of adult cicadas was correlated with cover of deep-rooted, perennial plants. Differences in perennial plant cover were independent of soil type and rock cover. On degraded rangelands, where perennial plants had been replaced by ephemerals and short-lived plants, cicada densities were significantly depressed. We concluded that vegetation transformation by domestic livestock is likely to affect invertebrate populations and their vertebrate predators.     

Comparison of biodiversity and ground cover between a commercial rotationally grazed property and an adjacent nature reserve in semi‐arid rangeland

Continuous livestock grazing can have negative effects on biodiversity and landscape function in arid and semi‐arid rangelands. Alternative grazing management practices, such as rotational grazing, may be a viable option for broad‐scale biodiversity conservation and sustainable pastoral management. This study compared ground cover, plant species composition and floristic and functional diversity along gradients of grazing intensity between a pastoral property rotationally grazed by goats and an adjacent nature reserve (ungrazed by commercial livestock) in semi‐arid south‐eastern Australia. Understorey plant species composition differed significantly between the rotationally grazed property and the nature reserve, with a greater proportion and frequency of palatable species recorded in the nature reserve. Understorey plant species richness, diversity, functional biodiversity measures and ground cover declined with increasing grazing pressure close to water points under commercial rotational grazing management. However, at a whole‐paddock scale, there were few differences in plant biodiversity and ground cover between the rotationally grazed property and the nature reserve, despite differences in overall plant species composition. Flexible, adaptive, rotational grazing should be investigated further for its potential to achieve both socio‐economic and biodiversity conservation outcomes in semi‐arid rangelands to complement existing conservation reserves.     

Impact of off-road vehicles on soil and vegetation in a desert rangeland in Saudi Arabia

Off-road vehicle driving is considered as main contributor to land degradation in arid regions. This study examined the impact of off-road vehicles (ORV) on soil and vegetation in a natural recreational desert meadow of Raudhat Khuraim, Saudi Arabia. Vegetation canopy cover and plant height away from road tracks were assessed. Also, species density and canopy cover, bare ground cover and soil attributes were assessed in four microhabitats; tracks, inter-tracks, verges, and away from vehicle tracks (undisturbed natural areas). Results show that the cover of forbs and grasses was negatively associated with distance from road verges. It was observed that the height of woody species responded negatively to distance away from tracks. Cover of native species decreased under verge, inter-track and track microhabitats giving more opportunity for weeds to flourish. Bare ground was highest (60.7%) in tracks. ORV impact on soil bulk density was clear with an increase of 38% under tracks compared to soils of undisturbed natural vegetation and a similar decrease in porosity was observed. On the other hand, soil electrical conductivity was significantly higher (5.45 mS cm^?1) under disturbance compared to 1.32 mS cm^?1 in undisturbed natural vegetation. Organic matter and nitrogen were not affected significantly by ORV disturbance. The results emphasize that managing off-road vehicle driving is essential for conserving native vegetation.     

Using faecal DNA to determine consumption by kangaroos of plants considered palatable to sheep

Disagreement exists within the scientific community with regards to the level of competition for feed between sheep and kangaroos in the Australian rangelands. The greatest challenge to solving this debate is finding effective means of determining the composition of the diets of these potential grazing competitors. An option is to adopt a non-invasive approach that combines faecal collection and molecular techniques that focus on faecal DNA as the primary source of dietary information. As proof-of-concept, we show that a DNA reference data bank on plant species can be established. This DNA reference data bank was then used as a library to identify plant species in kangaroo faeces collected in the southern rangelands of Western Australia. To enhance the method development and to begin the investigation of competitive grazing between sheep and kangaroos, 16 plant species known to be palatable to sheep were initially targeted for collection. To ensure that only plant sequences were studied, PCR amplification was performed using a universal primer pair previously shown to be specific to the chloroplast transfer RNA leucine (trnL) UAA gene intron. Overall, genus-specific, single and differently sized amplicons were reliably and reproducibly generated; enabling the differentiation of reference plants by PCR product length heterogeneity. However, there were a few plants that could not be clearly differentiated on the basis of size alone. This prompted the adoption of a post-PCR step that enabled further differentiation according to base sequence variation. Restriction endonucleases make sequence-specific cleavages on DNA to produce discrete and reproducible fragments having unique sizes and base compositions. Their availability, affordability and simplicity-of-use put restriction enzyme sequence (RES) profiling as a logical post-PCR step for confirming plant species identity. We demonstrate that PCR-RES profiling of plant and faecal matter is useful for the identification of plants included in the diet of kangaroos. The limitations, potential and the opportunities created for researchers interested in investigating the diet of competing herbivores in the rangelands are discussed.     

Resource use of specialist butterflies in agricultural landscapes: conservation lessons from the butterfly Phengaris (Maculinea) nausithous

Most of the European grassland butterfly species are dependent on species rich grasslands shaped by low intensity farming. Conservation of these specialist species in agricultural landscapes relies on knowledge of their essential resources and the spatial distribution of these resources. In The Netherlands, the dusky large blue Phengaris (Maculinea) nausithous butterflies were extinct until their reintroduction in 1990. In addition, a spontaneous recolonization of road verges in an agricultural landscape occurred in 2001 in the southern part of The Netherlands. We analyzed the use of the essential resources, both host plants and host ants, of the latter population during the summers of 2003 and 2005. First we tested whether the distribution of the butterflies during several years could be explained by both the presence of host plants as well as host ants, as we expected that the resource that limits the distribution of this species can differ between locations and over time. We found that oviposition site selection was related to the most abundant resource. While in 2003, site selection was best explained by the presence of the host ant Myrmica scabrinodis, in 2005 it was more strongly related to flowerhead availability of the host plant. We secondly compared the net displacement of individuals between the road verge population and the reintroduced population in the Moerputten meadows, since we expected that movement of individuals depends on the structure of their habitat. On the road verges, butterflies moved significantly shorter distances than on meadows, which limits the butterflies in finding their essential resources. Finally we analyzed the availability of the two essential resources in the surroundings of the road verge population. Given the short net displacement distances and the adverse landscape features for long-distance dispersal, this landscape analysis suggests that the Phengaris population at the Posterholt site is trapped on the recently recolonized road verges. These results highlight the importance of assessing the availability of essential resources across different years and locations relative to the movement of the butterflies, and the necessity to careful manage these resources for the conservation of specialist species in agricultural landscapes, such as this butterfly species.     

Road networks predict human influence on Amazonian bird communities

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called ‘roadless volume (RV)’ at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation.     

Road vegetation in Central Europe — an example from the Czech Republic

Road nets are man-made constructions in the open landscape with a specific vegetation accompaniment in a verge or band along the road or in a divider strip. A determination of six basic vegetation types of bands along roads is possible in Central Europe (tree lines, planting area, forest stand, early successful growth, bushes band, grassy-herbal associations). In the Czech Republic, grassy-herbal communities growing on road verges are mainly formed by perennials, hemicryptophyts, and species with tendency towards pollination by insects and to anemochory and exozoochory. 40% woody and 25% herbaceous species which are non-native for Central Europe form a part of them. Three halophyte species are growing in closed lines along asphalt: Puccinellia distans, Digitaria sanguinalis and Spergularia rubra. Roads and highways should be made and used with respect to the ecological potential of roadside vegetation. However, the road net functioned as a corridor for invasive (planting or spreading) plant species.     

Road verges as habitat for small mammals in Britain

There are 370 000 kilometres of roads in Great Britain, mostly bordered by a verge that is potential habitat for small mammals. The present study assessed the importance of road verges as small mammal habitat and investigated the influence of some key features on rodent abundance. Five rodent and three shrew species were live‐trapped on 14 road verges in late summer 1994 and nine verges in autumn 1996 in north Cambridgeshire, UK. On average, between three and four species were captured per verge. Bank Voles Clethrionomys glareolus, Wood Mice Apodemus sylvaticus and Field Voles Microtus agrestis were the most abundant species, with mean densities of 45.5, 40.2 and 29.5 animals km^–1 in summer and 52.8, 181.9 and 47.2 animals km^–1 in autumn. Numbers varied between verges and this was significantly correlated with particular features on the verge. Bank Vole and Field Vole numbers showed a significant positive correlation with the dimensions of hedges and the width of the tall grass area, respectively. Wood Mice were also more numerous on verges with big hedges but the relationship between mouse abundance and verge structure was complex. The number of mice in 1994 was positively and significantly correlated with hedge features and with the width of the short grass sightline, whereas, in autumn 1996, they were only significantly correlated with total verge width (positive association) and ditch width (negative association).     

Land‐use legacies and present fire regimes interact to mediate herbivory by altering the neighboring plant community

Past and present human activities, such as historic agriculture and fire suppression, are widespread and can create depauperate plant communities. Although many studies show that herbivory on focal plants depends on the density of herbivores or the composition of the surrounding plant community, it is unclear whether anthropogenic changes to plant communities alter herbivory. We tested the hypothesis that human activities that alter the plant community lead to subsequent changes in herbivory. At 20 sites distributed across 80 300 hectares, we conducted a field experiment that manipulated insect herbivore access (full exclosures and pseudo‐exclosures) to four focal plant species in longleaf pine woodlands with different land‐use histories (post‐agricultural sites or non‐agricultural sites) and degrees of fire frequency (frequent and infrequent). Plant cover, particularly herbaceous cover, was lower in post‐agricultural and fire suppressed woodlands. Density of the dominant insect herbivore at our site (grasshoppers) was positively related to plant cover. Herbivore access reduced biomass of the palatable forb Solidago odora in frequently burned post‐agricultural sites and in infrequently burned non‐agricultural woodlands and increased mortality of another forb (Pityopsis graminifolia), but did not affect two other less palatable species (Schizachyrium scoparium and Tephrosia virginiana). Herbivory on S. odora exhibited a hump‐shaped response to plant cover, with low herbivory at low and high levels of plant cover. Herbivore density had a weak negative effect on herbivory. These findings suggest that changes in plant cover related to past and present human activities can modify damage rates on focal S. odora plants by altering grasshopper foraging behavior rather than by altering local grasshopper density. The resulting changes in herbivory may have the potential to limit natural recovery or restoration efforts by reducing the establishment or performance of palatable plant species.