Cattle grazing and the regeneration of totara (

Totara-matai forests are an under-represented forest type in Westland, relative to their original extent, and require protection and enhancement where possible. This study examined the regeneration of totara on gorse-covered river terraces of the Whataroa and Waiho Rivers, on a site grazed by cattle at Whataroa, and ungrazed sites at both locations. Totara is regenerating prolifically at all sites. Tall-seedling densities were significantly higher at the grazed Whataroa site than at the ungrazed Whataroa site. Conversely densities of small seedlings were significantly higher at the ungrazed Waiho site, with the majority of seedlings occurring on raised surfaces created by rafted logs or occasional silt patches, than at either of the Whataroa sites where seedlings established on the ground. Sapling and tree densities were similar at both Whataroa sites, but significantly greater than at the Waiho site. There was a significant relationship between the density of saplings and trees with terrace age at the Whataroa sites. Gorse cover and seedling density were significantly related at both ungrazed sites, but not at the grazed site. Grazing and gorse cover both appear to have roles in totara regeneration on river terraces. The implications of current management for future forest development are discussed, and it is considered that these areas warrant designation as areas of significant indigenous vegetation because of their conservation potential.     

Intensified grazing affects endemic plant and gastropod diversity in alpine grasslands of the Southern Carpathian mountains (Romania)

Alpine grasslands in the Southern Carpathian Mts, Romania, harbour an extraordinarily high diversity of plants and invertebrates, including Carpathic endemics. In the past decades, intensive sheep grazing has caused a dramatic decrease in biodiversity and even led to eroded soils at many places in the Carpathians. Because of limited food resources, sheep are increasingly forced to graze on steep slopes, which were formerly not grazed by livestock and are considered as local biodiversity hotspots. We examined species richness, abundance and number of endemic vascular plants and terrestrial gastropods on steep slopes that were either grazed by sheep or ungrazed by livestock in two areas of the Southern Carpathians. On calcareous soils in the Bucegi Mts, a total of 177 vascular plant and 19 gastropod species were recorded. Twelve plant species (6.8%) and three gastropod species (15.8%) were endemic to the Carpathians. Grazed sites had lower plant and gastropod species richness than ungrazed sites. Furthermore, grazed sites harboured fewer gastropod species endemic to the Carpathians than ungrazed sites. On acid soils in the Fagaras Mts, a total of 96 vascular plant and nine gastropod species were found. In this mountain area, however, grazed and ungrazed sites did not differ in species richness, abundance and number of endemic plant and gastropod species. Our findings confirm the high biodiversity of grasslands on steep slopes in the Southern Carpathian Mts and caution against increasing grazing pressure in these refuges for relic plants and gastropods as well as for other invertebrates.     

Recovery of understorey vegetation after release from a long history of sheep grazing in a herb‐rich woodland

The effects of stock grazing on native grassy ecosystems in temperate southern Australia are well documented. However, less is known about the potential of ecosystems to recover after a long history of stock grazing and, in particular, whether the removal of stock will have positive, negative or neutral impacts on biodiversity. We examined the response of understorey vegetation to the removal of sheep grazing in a herb‐rich Eucalyptus camaldulensis (red gum) woodland in western Victoria. Using a space‐for‐time chronosequence, woodlands were stratified into groups based on their time‐since‐grazing removal; these were long‐ungrazed (>20 years), intermediate‐time‐since‐grazing (9–14 years), recently ungrazed (5 years) and continuously grazed. We found significantly higher species density in long‐ungrazed sites relative to sites with a more recent grazing history. No differences were found in species density between continuously grazed sites and those ungrazed in the previous 14 years. Species composition differed with time‐since‐grazing removal and indicator species analysis detected several native species (including tall native geophytes and herbs) associated with long‐ungrazed sites that were absent or in low abundance in the more recently grazed sites. Seven of the eight species significantly associated with continuously grazed sites were exotic. Removal of sheep grazing in red gum woodlands can have positive benefits for understorey diversity but it is likely that recovery of key indicators such as native species will be slow.     

The impact of herbivores on nitrogen mineralization rate: consequences for salt-marsh succession

Soil net N-mineralization rate was measured along a successional gradient in salt-marsh sites that were grazed by vertebrate herbivores, and in 5-year-old exclosures from which the animals were excluded. Mineralization rate was significantly higher at ungrazed than at grazed sites. In the absence of grazing, mineralization rate increased over the course of succession, whereas it remained relatively low when sites were grazed. The largest differences in mineralization rate between grazed and ungrazed sites were found at late successional stages where grazing pressure was lowest. The amount of plant litter was significantly lower at grazed sites. In addition, the amount of litter and potential litter (non-woody, live shoots) was linearly related to net N-mineralization rate. This implies that herbivores reduced mineralization rate by preventing litter accumulation. Bulk density was higher at grazed salt-marsh sites than at ungrazed sites. This factor may also have contributed to the differences in net N-mineralization rate between grazed and ungrazed sites. Received: 30 November 1997 / Accepted: 27 August 1998     

Top-down impact through a bottom-up mechanism: the effect of limpet grazing on growth,productivity and carbon allocation of Zostera marina L. (eelgrass)

The unusual appearance of a commensal eelgrass limpet [Tectura depicta (Berry)] from southern California at high density (up to 10 shoot^–1) has coincided with the catastrophic decline of a subtidal Zostera marina L. meadow in Monterey Bay, California. Some commensal limpets graze the chloroplast-rich epidermis of eelgrass leaves, but were not known to affect seagrass growth or productivity. We evaluated the effect on eelgrass productivity of grazing by limpets maintained at natural densities (8±2 shoot^–1) in a natural light mesocosm for 45 days. Growth rates, carbon reserves, root proliferation and net photosynthesis of grazed plants were 50–80% below those of ungrazed plants, but biomass-specific respiration was unaffected. The daily period of irradiance-saturated photosynthesis (H _sat) needed to maintain positive carbon balance in grazed plants approached 13.5 h, compared with 5–6 h for ungrazed plants. The amount of carbon allocated to roots of ungrazed plants was 800% higher than for grazed plants. By grazing the chlorophyll-rich epidermis, T. depicta induced carbon limitation in eelgrass growing in an other-wise light-replete environment. Continued northward movement of T. depicta, may have significant impacts on eelgrass production and population dynamics in the northeast Pacific, even thought this limpet consumes very little plant biomass. This interaction is a dramatic example of top-down control (grazing/predation) of eelgrass productivity and survival operating via a bottom-up mechanism (photosynthesis limitation).     

Effects of grazing on seedling establishment: the role of seed and safe-site availability

Abstract. The first objective of this paper was to assess the effects of grazing on seedling establishment of two species whose relative abundance at the adult stage is affected by grazing in a contrasting fashion. Second, we evaluated the relative importance of seed versus safe-site availability in explaining the effect of grazing on seedling establishment. We monitored seedling establishment on a grazed area, on two areas which had not been grazed for two and seven years, and on plots which had been experimentally defoliated. The species compared were Dan-thonia montevidensis, a native perennial grass which dominates both grazed and ungrazed communities, and Leontodón taraxacoides, an invading exotic rosette species from the Compositae family. Continuous grazing enhanced seedling establishment of both species through its effect on the availability of safe sites. Seed availability accounted for only one, but very important, grazing effect: the lack of response by L. taraxacoides to the defoliation in the seven-year old exclosure. Its seed supply was depleted by exclusion of grazing and, consequently, its short-term regeneration capacity after disturbance was lost.     

Leaf litterfall, fine-root production, and decomposition in shrublands with different canopy structure induced by grazing in the Patagonian Monte, Argentina

Selective sheep grazing in the Patagonian Monte induces the reduction of total and perennial grass cover, species replacement within life forms, and the increase in dominance of long-lived evergreen woody plants with slow growth rates and high concentration of secondary compounds in leaves. We hypothesized that these changes in the canopy structure induced by sheep grazing will affect the mass, chemistry and decomposability of leaf litter and fine roots. We selected two sites in the Patagonian Monte, representative of ungrazed and grazed vegetation states. At each site, we assessed canopy structure (total cover and absolute and relative grass and shrub cover), monthly leaf litterfall, and fine-root biomass and production in the upper soil (15 cm). We also estimated the rates of mass, C, soluble phenolics, lignin and N decay in litterbags containing both leaf litter and fine roots of each site under field conditions during two consecutive years. The ungrazed site exhibited higher total plant cover, absolute and relative grass- and shrub-cover than the grazed one. Leaf litterfall was lower at the grazed site than at the ungrazed site. Fine-root production did not vary between sites. Leaf litter and fine root tissues had higher concentration of secondary compounds at the grazed than at the ungrazed site. However, fine roots showed lower mass and C decay than leaf litter, attributable to the predominant secondary compound (lignin and soluble phenolics, respectively). Leaf litter decomposed slower but released more N during decay at the ungrazed than at the grazed site, probably due to its low concentration of secondary compounds. We concluded that changes in canopy structure induced by grazing disturbance such as those explored in our study could reduce leaf litterfall mass and increase the concentration of secondary compounds of both leaf litter and fine roots leading to slow N release to soil during decay.     

Impact of reindeer grazing on ground-dwelling Carabidae and Curculionidae assemblages in Lapland

Reindeer Rangifer tarandus L. grazing shapes forest vegetation, microclimate, and soil respiration in Lapland, especially due to grazing on lichens (Cladina). We studied how these changes and their magnitude affect ground‐dwelling species of beetle families Carabidae (predators) and Curculionidae (herbivores), by using pitfall traps to collect invertebrates from pairs of grazed and ungrazed study plots over a wide range of site types. Changes in abundance, composition, richness and diversity of beetle assemblage were tested in relation to magnitude of the impacts on vegetation. The species compositions of Carabidae and Curculionidae differed between grazed and ungrazed plots in all sites. The relative difference between grazed and ungrazed plots in the number of individuals increased linearly with the impact of reindeer on vegetation cover. Carabid beetles, as a family, were more common in grazed plots in all sites. Curculionid beetles were more common in ungrazed plots in the birch dominated sites. This difference was mainly due to the species that feeds on deciduous leaves. In the pine dominated sites with high Cladina cover and more changes in ground vegetation, the number of curculionids feeding on conifers was higher in grazed plots. Species richness and diversity (H’) of both families were higher in grazed plots. Of the total 27 species, 11 were found only in grazed plots, while not a single species was found only in ungrazed plots. The relative difference between plots in diversity and evennes (H’/H'max) had humped response to the difference in Cladina cover. The diversity values were greater in grazed plots at the intermediate levels of grazing impact, and only in sites with very low or extremely high Cladina cover difference was the diversity higher in ungrazed plots. The response of beetle diversity resembled the hypotheses suggested for the relationship between grazing and vegetation diversity: greatest positive effect at intermediate grazing intensity and negative effects at unproductive sites.     

Effects of Rotational Grazing on Nesting Ducks in California

Abstract: Grazing is thought to be incompatible with nesting by dabbling ducks (Anas spp.), but this belief is based on little data. We therefore conducted a 2-year, replicated field experiment to determine whether the habitat requirements of nesting ducks could be met on uplands managed by rotational grazing (1 Jul-1 Nov) in the northern San Joaquin Valley, California, USA. Grazed fields had shorter vegetation than ungrazed fields throughout the winter, but vegetation height did not differ by the beginning of the nesting season in late March, and by the end of the nesting season in late May, previously grazed fields had taller vegetation than did ungrazed fields. In 1996, densities of duck nests were >3 times higher in grazed than in ungrazed fields (least-squares means [± 1 SE]: grazed = 2.18 [0.34] nests/ha, ungrazed = 0.59 [0.34] nests/ha), but nest densities were substantially lower in 1997 and did not differ between treatment groups (grazed = 0.65 [0.32] nests/ha, ungrazed = 0.39 [0.32] nests/ha). Mayfield nest success did not differ between grazed fields (5.3%) and ungrazed fields (2.9%). We conclude that rotational grazing was successful in providing summer nesting habitat for dabbling ducks, and we recommend that it be considered for other managed habitats within the Central Valley, California, USA.     

放牧干扰下的蝗虫－植物相互作用关系

本文研究了内蒙古典型草原植物和蝗虫群落在不同放牧强度影响下的多样性、均匀性和丰盛度变化。比较了蝗虫群落与植物群落在放牧梯度上的相互作用关系。研究发现,放牧干扰活动会明显地影响植物和蝗虫群落结构,但蝗虫群落结构的变化趋势并非与植物完全同步。蝗早与植物间的联系列多地表现在植物起着蝗虫栖息地条件的作用,而并不完全是食料植物作用。文中对放牧实践与多样性保护的关系进行了讨论。     

Differential photosynthetic performance of three Mediterranean shrubs under grazing by domestic goats

The impact of grazing by domestic goats, Capra hircus, on the photochemical apparatus of three co-ocurring Mediterranean shrubs, Erica scoparia, Halimium halimifolium, and Myrtus communis was evaluated. Seasonal course of gas exchange, chlorophyll fluorescence and photosynthetic pigment concentrations were measured in the field in grazed and ungrazed plants. Net photosynthetic rate was higher in grazed plants of E. scoparia and H. halimifolium in May, while there were not significant differences in M. communis. Photosynthetic enhancement in grazed plants of E. scoparia could be explained largely by higher stomatal conductance. On the other hand, the lack of differences in stomatal conductance between grazed and ungrazed plants of H. halimifolium could indicate that carboxylation efficiency, and ribulose-1,5-bisphosphate (RuBP) regeneration may have been enhanced by grazing. Overall grazing has little effect on the photochemical (PSII) apparatus, however grazed plants of M. communis showed chronic photoinhibition in the short term. Finally, seasonal variations recorded on photosynthesis, photochemical efficiency and pigment concentrations may be a physiological consequence of environmental factors, such as summer drought and competition for light, rather than an adaptation to grazing.     

Interactive effects of fire and grazing on structure and diversity of Mediterranean grasslands

Abstract. The separate and combined effects of fire and cattle grazing on structure and diversity of productive Mediterranean grasslands in northern Israel were examined within a set of climatically and edaphically similar sites. Cover and height of green and dry plants in winter, and species richness and diversity in spring, were measured in paired transects on both sides of cattle fences, and on both sides of boundaries of both incidental and experimentally lit fires. Early in the first growing season after a fire, plant cover as well as height of green plants were reduced, compared to unburnt grassland. These structural effects of fire were similar to the effects of grazing, but they were greater in ungrazed than in grazed grasslands, indicating a fire-grazing interaction. The effects of fire were considerably attenuated in the second growing season after the fire. Species richness and diversity tended to be higher in grazed than in adjacent ungrazed grasslands. Richness consistently increased after a fire only in grazed grasslands with a strong perennial component. In ungrazed grasslands, and in predominantly annual grasslands, fires reduced species richness and diversity at least as often as they increased it. Fire and grazing should be regarded as two agents with distinct and interactive effects on the community, rather than as two alternative mechanisms of a general disturbance factor.     

The effects of grazers on the performance of individuals and populations of scarlet gilia,Ipomopsis aggregata

Summary I. aggregata exhibits considerable powers of regrowth following removal of its primary shoot by herbivores, but we found no evidence of overcompensation (i.e. of significantly higher plant performance where plants were exposed to ungulate herbivory) in a comparison between individuals on grazed and ungrazed sides of exclosure fences, in a comparison between artificially clipped and control plants in one population in the Okanagan National Forest, or in comparisons between grazed and ungrazed plants in 14 natural populations. We tested whether ungulate grazing affects the population size of Ipomopsis aggregata by comparing populations inside and outside deer exclosures at 7 sites in the Western United States. We found consistent, highly significant differences in plant population density on the grazed and ungrazed sides of these exlosure fences. Plant density was a modal 25-fold higher on the protected side of the fence, suggesting that exposure to ungulate grazing increases plant death rates at some stage in the life cycle. Our results show that the presence of ungulate grazers leads to a substantial decrease in plant density despite the fact that grazing on young bolting shoots has very little influence on fruit production. Since this decrease in population density is not correlated with a decrease in the fecundity of individuals, it must instead be due to other direct and indirect effects of ungulate grazers.     

The effect and extent of heavy grazing by reindeer in oligotrophic pine heaths in northeastern Fennoscandia

Thirty and fifty years old exclosures established in northeastern Fennoscandia in lichen-rich oligotrophic pine Pinus sylvestris forests on podzolised soil were used to study the effect of reindeer grazing on pine fine roots, microbial activity, and on bryophyte, dwarf shrub and lichen biomasses. There were significantly less lichens, especially Cladina stellaris , at grazed than at ungrazed sites. Coverage of other lichens like C. arbuscula and C. rangiferina and bryophytes, especially Dicranum spp., benefitted from grazing. The biomass of vascular plants, mainly Calluna vulgaris, Empetrum nigrum and Vaccinium vitis-idaea , was reduced at grazed sites, although their coverage was not influenced. Microbial activity was significantly lower at grazed sites. The influence of grazing is most obviously mediated by reduced soil moisture during dry periods at grazed sites. Fine root parameters (per soil and stem volumes) were lower at grazed sites (pPCA = 0.072), the first principal component consisting of a number of fine root tips, length and weight. Grazing decreased all exchangeable nutrients by 30–60% in organic layer. Based on PCA the decrease was significant for exchangeable nutrients, although of individual elements only P and S showed statistically significant difference. The extent of heavy grazing in northeastern Fennoscandia coniferous forest was revealed by remote sensing. It revealed extensive area in which reindeer lichens are reduced in northeastern Finland. The Finnish-Russian border can be clearly distinguished in the satellite image composite.     

Soil and plant water relations in a crested wheatgrass pasture: response to spring grazing by cattle

Summary Few field studies have attempted to relate effects of actual livestock grazing on soil and plant water status. The present study was initiated to determine the effects of periodic defoliations by cattle during spring on soil moisture and plant water status in a crested wheatgrass (Agropyron cristatum (L.) Gaertn. and A. desertorum (Fisch. ex Link) Schult.) pasture in central Utah. Soil moisture in the top 130 cm of the soil profile was depleted more rapidly in ungrazed plots than in grazed plots during spring and early summer. Soil moisture depletion was more rapid in grazed plots in one paddock after 1 July due to differential regrowth, but there was no difference in soil water depletion between plots in another paddock during the same period. This difference in soil water depletion between paddocks was related to a difference in date of grazing. Although more water had been extracted from the 60 cm to 130 cm depths in ungrazed plots by late September, cumulative soil moisture depletion over the entire 193 cm profile was similar in grazed and ungrazed plots. Prior to 1 July, grazing had no effect on predawn leaf water potentials as estimated by a pressure chamber technique; however, after 1 July, predawn leaf water potentials were lower for ungrazed plants. Midday leaf water potentials were lower for grazed plants before 1 July, but did not differ between grazed and ungrazed plants after 1 July. A 4- to 8-day difference in date of defoliation did not affect either predawn or midday leaf water potentials. The observed differences in water use patterns during spring and early-summer may be important in influencing growth and competitive interactions in crested wheatgrass communities that are subject to grazing by domestic livestock.     

Long‐term effects of exclusion of grazing stock on degraded herbaceous plant communities in a riparian Eucalyptus camaldulensis forest in south‐eastern Australia

Abstract Stock grazing has degraded many riparian ecosystems around the world. However, the potential for ecosystem recovery following the removal of grazing stock is poorly known. We developed a conceptual model to predict the responses of native and exotic herbaceous plants to grazing exclusion, based on site productivity and the degree of initial vegetation degradation. The effects of excluding grazing stock on richness, cover and composition of herbaceous plants were examined over 12 years in the degraded understorey of a riparian forest in Gulpa Island State Forest in south‐eastern Australia. We predicted that grazing exclusion would lead to limited changes in vegetation cover, richness and composition, owing to presumed low site productivity and the high degree of understorey degradation. Results showed that the cover, richness and composition of native and exotic species varied significantly among years. Over all plots, regions and years, total cover was slightly but significantly lower in grazed than in ungrazed plots (43.4% vs. 50.8%). While the cover of native plants increased over time in both treatments, the rate of increase was slightly greater in ungrazed plots. Grazing exclusion had no effect on the richness of native or exotic species, but had a significant but minor impact on plant composition, with different common species (mostly exotics) being promoted or diminished in ungrazed plots. The composition of grazed and ungrazed areas did not become more different over time. Overall, the effects that could be attributed to grazing exclusion were relatively minor and transient. Results are consistent with predictions based on site productivity and initial degradation, and should not be extrapolated to other more productive, or less degraded, riparian systems.     

Does selective defoliation mediate competitive interactions in a semiarid savanna? A demographic evaluation

Abstract. Three patterns of target-neighbor plant defoliation were imposed on a late-seral, perennial, C₄-grass, Bouteloua curtipendula, in three long-term grazing regimes to determine the influence of selective defoliation on competitive interactions and species replacement in a semiarid savanna on the Edwards Plateau, Texas, USA. Short-term (3-yr) target plant defoliation did not significantly affect either tiller or plant responses in any of the three grazing regimes. Neighbor plant defoliation, either alone or in combination with target plants, produced a significant defoliation interaction with time for tiller number and basal area per plant, but not for tiller recruitment or mortality. The minimal effect of selective defoliation on the intensity of competitive interactions in this semiarid community indicates that selective grazing has a less definitive role in mediating herbivore-induced species replacement than it does in mesic grasslands and savannas. This interpretation is discussed within the context of long-term (45-yr) change in herbaceous vegetation associated with grazing in this community. Cumulative tiller recruitment in the intensively grazed regime was only 44% of that in the ungrazed regime because of greater plant mortality and fewer surviving plants that recruited tillers. Target plant mortality (50%) only occurred in the intensively grazed regime and the proportion of target plants that initiated tillers decreased by 70, 48 and 32% in the ungrazed, moderately and intensively grazed regimes, respectively, during the final two years of the investigation. The decrease in cumulative tiller recruitment in all grazing regimes was probably mediated by a drought-induced increase in median tiller age the second year of the study. However, tiller per tiller recruitment rate among plants that recruited at least one tiller remained relatively constant among grazing regimes and years. Intensive, long-term grazing has modified the population structure of this late-seral perennial grass to the extent that population responses to both herbivory and periodic drought have been altered in comparison with those of ungrazed and moderately grazed populations. Ecological consequences of a herbivore-induced transition in population structure may be to minimize the effect of selective herbivory on competitive interactions and to function as an avoidance mechanism to reduce the probability of localized population extinction in response to intensive long-term herbivory.     

Effects of reindeer grazing on understorey vegetation in dry Pinus sylvestris forests

Abstract. Data on floristic composition and environmental variables were collected in floristically homogeneous oligotrophic pine (Pinus sylvestris) forests with heath-like under- storey vegetation in eastern Fennoscandia, and ordinated by non-linear multidimensional scaling (NMDS) in order to study the effect of lichen grazing by reindeer on the understorey vegetation. The study sites included areas with varying grazing pressure, as well as 50-yr old grazing exclosures. Sites rich in respectively bryophytes and lichens were placed at opposite ends of the ordination axes, and heavily grazed sites were placed in between them. Reindeer grazing increased the abundance of bryophytes, especially Dicranum spp. and Pleurozium schreberi. Grazing changed the vegetation to the extent that it resembled more mesotrophic sites, but this did not show any relationship with tree volume or other site productivity indicators. This was observed both in the ordination and, in a more compelling way, when exclosures with adjacent grazed areas were compared. No such signs were evident at ungrazed sites, where especially Cladina spp. spatially replace Cladonia spp. and tiny bryophytes like Barbilophozia spp., Polytrichum spp. and Pohlia nutans during succession. Cladina stellaris had almost disappeared from the most intensively grazed sites. The soil at ungrazed sites was characterized by high Al and Fe concentrations and bryophyte-rich sites by high Mn concentrations. Shannon's diversity index, depth of humus layer and proportion of bare ground also increased in sites getting richer in bryophytes.     

Utilisation of Wadden Sea salt marshes by geese in relation to livestock grazing

To arctic breeding geese, the salt marshes of the International Wadden Sea are important spring staging areas. Many of these marshes have always been grazed with livestock (mainly cattle and sheep). To evaluate the influence of livestock grazing on composition and structure of salt-marsh communities and its consequences for habitat use by geese, a total of 17 pairs of grazed and ungrazed marshes were visited both in April and May 1999, and the accumulated grazing pressure by geese was estimated using dropping counts. Observed grazing pressure was related to management status and to relevant vegetation parameters.The intensity of livestock grazing influences the vegetation on the marsh. Salt marshes that are not grazed by livestock are characterised by stands with a taller canopy, a lower cover of grasses preferred by geese, and a higher cover of plants that are not preferred.Overall goose-dropping densities are significantly lower in ungrazed marshes compared to marshes grazed by livestock. Some ungrazed marshes had comparatively high goose grazing pressure, and these were all natural marshes on a sandy soil, or artificial mainland marshes with a recent history of intensive livestock grazing. Goose grazing is associated with a short canopy. The plant communities with short canopy, dominated by Agrostis stolonifera, Festuca rubra and Puccinellia maritima, together account for 85% of all goose droppings in our data.The sites that were not visited by geese differed very little from those that were visited, in the parameters we measured. This might indicate that there was no shortage of available habitat for spring staging geese in the Wadden Sea, in the study period.     

Managed grazing is an effective strategy to restore habitat for the endangered autumn buttercup (Ranunculus aestivalis)

The only protected habitat of the endangered autumn buttercup is a small, overgrown, wet meadow that no longer supports the species. We used an experimentally driven reintroduction to examine the role of rodent herbivory in limiting the survival and establishment of autumn buttercup at the site. We evaluated the effectiveness of livestock grazing and cages to exclude rodents by comparing survival of caged and uncaged transplants under two pasture management treatments (grazed vs. ungrazed). We found that transplant survival was greatest for caged plants in grazed pasture with 50% of plants surviving to the end of the second growing season. Grazing increased the species richness in the plant community and decreased the amount of cover for small mammals. Accordingly, rodent density and vole herbivory in late summer were significantly lower on grazed pasture. Our results indicate that rodent herbivores represent a major threat to the survival and reestablishment of autumn buttercup and livestock grazing and protective caging are effective strategies to reduce rodent populations and vole herbivory.