Biodiversity Of Pastures Research Articles

Characteristics of mountain vs. lowland dairy products

SummaryBesides the clean environment, mountain pastures are important sources of bioactive compounds that contribute to the quality of dairy products resulting from animals grazing there. This review aimed to compare the main differences among mountain and lowland dairies in terms of chemical composition, physical and sensory properties and microflora. The most important factors influencing final product properties are the biodiversity of pastures and the abundance of plants in terpenes and fatty acids, farm practices, animal breeds and climatic conditions. Differences between dairies from lowland and mountain products were observed regarding the sensory profile, microflora and nutritional and functional value. The comparisons of the results presented in the literature concluded that some mountain dairies presented more than 50% higher content of terpenes compared to lowland products. Furthermore, the amounts of polyunsaturated fatty acids (PUFA) were more than 15% greater in mountain products compared to lowland ones, conjugated linoleic acids more than 35%, n−6 and n−3 PUFA more than 10%, while the saturated fatty acids content was reported to be more than 3% lower in mountain dairies. In conclusion, mountain dairy products can be distinguished from lowland ones, especially by their content of terpenes and fatty acid profile, along with the microflora which are influenced by livestock management.

Challenges of Pasture Feeding Systems—Opportunities and Constraints

Grazing plays an important role in milk production in most regions of the world. Despite the importance of grazing, current trends in livestock farming in Europe are causing a decline in the popularity of pasture-based feeding of dairy cows. This paper aims to provide an overview of the challenges faced by the pasture feeding system under climate change. Grazing lands provide ecosystem services including regulation and storage of water flows, nutrient cycling, and C sequestration. Livestock grazing is the most important factor shaping and stabilizing pasture biodiversity. Some opportunities for pasture feeding are the health-promoting and nutritional qualities of milk and milk products, especially milk from pasture-fed cows. The beneficial effects of pasture feeding on animal health and welfare are not insignificant. Available organizational innovations can help better manage livestock grazing and, above all, better understand the impact of the grazing process on the environment and climate change.

Composition, abundance and biodiversity of terrestrial arthropods in pastures and their relationship with landscaping plants

We investigated the association of landscaping plants with the communities of ground-dwelling arthropods within pastures and tested the hypothesis that arthropod biodiversity increases with vegetation heterogeneity. The community characterization and biodiversity of arthropods in a pasture were compared with those within communities with landscaping plants, including forest remnants, Forsythia koreana and Prunus serotina. The total abundance of mites was greater within the forest remnants than within the pasture; however, the abundance of insects and spiders did not differ. Nonmetric multidimensional scaling and the multiresponse permutation procedure revealed that the community composition of insects and spiders differed according to vegetation type. The abundance of Teleogryllus emma was highest within the forest remnant community, which suggested the species’ dependency on vegetation type. Species richness and the Shannon index of insects increased within F. koreana but not within P. serotina compared with the pasture. This suggested that belts of shrubs might have a greater promoting effect on insect biodiversity than belts of trees. Species richness of spiders did not differ by vegetation type. The total number of insect and spider species within the study area increased by 2.8 and 3.5 times, respectively, by establishing three types of vegetation. These results suggested that increasing vegetation heterogeneity by establishing landscaping plants is a good option for conserving insect and spider biodiversity in pastures.

Developing a future protocol for measuring spider biodiversity in pastures in New Zealand

ABSTRACT Arthropods are often ignored or under-sampled in biodiversity and conservation assessments because of their large diversity, small size and lack of taxonomic guides. Rapid biodiversity assessment programmes have been established to assess these groups accurately. A COBRA (Conservation Oriented Biodiversity Rapid Assessment) protocol consists of an intense sampling of a habitat using the optimal combination of sampling methods. We set a basis for future protocols of measuring spider biodiversity in exotic pastures in New Zealand. Overall, 28 spider species were collected. There was variation in species discovery for each collection method, i.e. pitfall traps (86.6% of total species found), ground hand collection (95.4%), suction sampling (85.7%), and sweeping (25%). The various collection methods were complementary in species that were found. Of the four sampling methods used pitfall traps and ground hand collection were far more efficient at collecting spider species in pastures per sample. These findings are relevant for the future development of these protocols and ultimately, these tools will be used for assessing and monitoring biodiversity on farms and the impacts of farming methods.

Floristic Composition: Dynamic Biodiversity Indicator of Tree Canopy Effect on Dryland and Improved Mediterranean Pastures

Montado is a characteristic ecosystem of the Mediterranean region. The adequate management of this silvo-pastoral ecosystem requires good understanding of the effect of factors such as tree canopy, fertilization and soil amendment on pasture growth. The main objectives of this work were: (1) to evaluate the effect of tree canopy on soil characteristics and pasture productivity and quality; and (2) to test floristic composition assessment as a bio-indicator of soil improvements (amendment and fertilization) in each study area (under and outside tree canopy). Topsoil was characterized at the beginning of the project (October 2015) and at the end of the experiments (spring 2020). Soil parameters obtained by electronic sensors (soil moisture content, soil cone index and surface temperature) were monitored monthly during the 2017/2018 pasture vegetative cycle. Pasture productivity, quality and floristic composition were evaluated every two years (2016, 2018 and 2020) in the spring flowering period. The results of the floristic inventory were submitted to a multilevel pattern analysis (Indicator Species Analysis, ISA). Pasture biodiversity was evaluated based on the calculation of richness indices. This study showed a positive effect of tree canopy on soil fertility and pasture quality (e.g., CP). Pasture productivity, on the other hand, was higher in areas outside tree canopy. The great potential of ISA as a tool for identification of bio-indicator species was also demonstrated. Pasture species were identified as ecological and dynamic attributes characteristic of each study area, before and after soil amendment and fertilization.

Lasting decrease in functionality and richness: Effects of ivermectin use on dung beetle communities

Use of ivermectin in agro-ecosystems negatively affects non-target dung beetles, which provide keystone ecosystem services for pasture functioning. While the direct effects of ivermectin on dung beetles are at the center of scientific attention, its long-lasting effects on routinely treated pastures have not yet been studied on real communities and under field conditions. We focused on basic characteristics (species richness, abundance, biomass) and functionality (dung removal ability represented by guild composition) of dung beetle communities in response to ivermectin treatment. We selected 15 sites with routine ivermectin treatment and 11 without any treatment, both for at least five consecutive years prior to our sampling. We covered wide range of climatic conditions in the Czech Republic, seasonal variability, and sampled the dung of four main herbivore dung types. Additionally, we separated the samples from ivermectin treated sites into two categories, i) recently treated representing immediate effects (treated <8 weeks prior to sampling, expected lethal or sublethal levels of residues), and ii) long-ago treated representing lasting effects (treated >8 weeks, expected sublethal or inconsequential levels of residues). Ivermectin treated sites had ca. 35% lower species richness and 44% lower abundance per pat. Per pat biomass did not change. However, from a functional perspective, ivermectin use significantly decreased the biomass of beetles with high contribution to dung removal (relocating and dwelling beetles), while the biomass of beetles with low contribution (dung visiting adults with saprophagous larvae) was not affected. This was accomplished with decrease in per pat functionality at treated sites, i.e., the dung removal ability of the community. Our results highlight that the effects of ivermectin use can last far beyond its physical presence in the grazing system. Via its effects on dung beetles, routine antiparasitic treatment by ivermectin has negative consequences for both pasture biodiversity and ecosystem functioning. Therefore, all alternatives should be carefully considered to ensure that the positives of any antiparasitic treatment outweigh the damages. In areas where biodiversity is of concern, as well as in organic farming systems, all precautions should be taken to avoid excretion of toxic residues on-site.

Local Small Ruminant Grazing in the Monti Foy Area (Italy): The Relationship Between Grassland Biodiversity Maintenance and Added-Value Dairy Products.

The literature indicates that grazing small ruminants, when adequately managed, contributes to grassland biodiversity maintenance. On the other hand, milk and cheese from grazing animals show higher nutritional and aromatic quality than those from stall-fed animals. The relationship between the two issues has rarely been addressed. This article provides information for a discussion of this relationship. First, two case studies are reported. Local breeds of small ruminants fed by grazing on pastures within the Special Area of Conservation “Monti Foy” in the Northwestern Basilicata region (Italy), with a stocking rate of 4.0 LU ha−1 year−1, showed the best effectiveness for the maintenance of grassland botanical biodiversity. Milk and cheese from pasture-fed goats showed higher contents of beneficial fatty acids, phenols, and vitamins A and E; higher degree of antioxidant protection; and richer volatile compound profiles, in particular for terpenes content. Finally, some recommendations for the management of grazing systems in similar mountain areas are offered, including a viable approach for land managers to preserve the grassland biodiversity of pastures and provide high-quality products that are valuable both for their nutritional quality and for their contribution to the economic sustainability of mountain communities.

Improvement of Degraded Pastures in the Foothills and Sandy Desert Zone of Uzbekistan by Implementing Best Practices

The article presents the best practices for the restoration of degraded pastures in the foothill zone of the Zamin district of Jizzak region and the sandy desert of Karakul district of the Bukhara region carried out by a UNDP project. On the degraded lands, measures were taken to restore the biodiversity of pastures, preserve landscape-ecological systems. The implementation of reclamation measures for the retention of moving sands, for the creation (restoration) of protective forest belts in pastures, reproduction of pasture productivity by artificial by additional sowing seeds in degraded areas, restoration of pasture infrastructure, bringing non-working wells and wells into working order. Key words: foothills, Kyzylkum desert, degradation, drought-resistant fodder plants, seeds, seedlings, technology, grazing DOI : 10.7176/JSTR/6-10-12

Evaluation of the Nutritive Value and the Fatty Acid, Phenol, Tannin and Terpenoid Contents of Nine Pastures in an Alpine District during the Summer Season

A study was conducted over the summer of 2014 on nine Alpine pastures in the Chisone and Susa Valleys (NW Italy). The aim was to characterize the variation in the chemical composition, gross energy, in vitro true digestibility (IVTD), in vitro neutral detergent fiber digestibility (NDFD), fatty acids (FA), total phenols, total and condensed tannin contents, and terpenoid profile. The dry matter, ash, crude protein, acid detergent fiber, lignin, and gross energy contents of the pastures were found to differ. All the pastures had good IVTD (706–829 g/kg DM) and NDFD (487–694 g/kg NDF) values. The most abundant FAs in all the pastures were α-linolenic (354–519 g/kg of the total FAs), linoleic (75–110 g/kg of the total FAs), and palmitic acid (64–89 g/kg of the total FAs) and they differed significantly among pastures. No significant differences were found in the total phenols, or in the total and condensed tannin contents among pastures. Fifty-eight terpenoids were detected and 4-cyclopentene-1, 3-dione, β-caryophyllene, and eucalyptol were the most abundant. The terpenoids differed both qualitatively and quantitatively among pastures. The results highlight the importance of the great biodiversity of pastures, which provide a balanced distribution of fundamental nutritional elements and bioactive compounds in grasslands.

Alpine and lowland grazing differentially alter the reproductive tract redox milieu and amino acid composition in cattle

An alpine environment is unique due to pasture biodiversity, with an abundant content of natural antioxidant polyphenols. The present study investigated the effects of lowland and alpine grazing on the oviduct and uterine tissue redox status and amino acid concentrations in plasma and reproductive fluids. In the first experiment, heifers grazed on lowland (H-LOW: n = 13) and on alpine (H-ALP: n = 15) pastures. In the second experiment, heifers grazed on the same lowland (HS-LOW: n = 6) and on a different alpine (HS-ALP: n = 6) pasture. The abundance of mRNA transcripts for antioxidant enzymes in the oviduct (glutathione S-transferase alpha 2, glutathione synthetase (GSS)) and the endometrium (catalase, glutathione-disulfide reductase, GSS) was less (P < 0.05), and for glutathione peroxidase 4 in the endometrium greater (P = 0.006) in the H-LOW than in the H-ALP group. The abundance of mRNA transcript for catalase was less in the endometrium in the H-LOW than in the H-ALP (P = 0.001) group. Catalase and NAD(P)H quinone dehydrogenase 1 concentrations in the oviduct were greater in the HS-LOW than in the HS-ALP group (P < 0.05). Of 32 amino acids analysed, there were differences in concentrations in the H-LOW and H-ALP group of 13, seven and 15 in plasma, oviduct and uterine fluids, respectively (P < 0.05). Comparing the HS-LOW to the HS-ALP groups, there were 13, one and three amino acids in the plasma, oviduct and uterine fluids, respectively, that were differentially abundant (P < 0.05). The grazing systems had some effect on the redox status and amino acid patterns in reproductive tissues.

How does stocking rate influence horse behaviour, performances and pasture biodiversity in mesophile grasslands?

Reducing grazing intensity is widely recommended as a strategy to increase grassland biodiversity through greater sward heterogeneity. Horses are playing an increasing role in the management of permanent grasslands across Europe, but the effects of horse grazing under contrasting stocking rates have been poorly studied. Here we describe the effects of two contrasted stocking rates (“High” 1.8LUha−1vs. “Moderate” 1.1LUha−1) on sward structure, horse foraging behaviour and performances, and pasture biodiversity in a mesophile grassland of central France. Horses selectively grazed vegetative patches of high nutritive value, especially at the moderate stocking rate (p<0.01). This enabled them to maintain diet quality (diet dry matter digestibility: 59% DM) and performances (daily liveweight gain>270ganimal−1d−1) at the same level in highly and moderately grazed plots despite contrasted herbage biomass and quality. Horses, with their two sets of incisors, created and maintained patches of short grass in a matrix of tall vegetation in both treatments. Consequently, sward structural heterogeneity did not significantly differ between highly and moderately grazed plots, and there was no detectable effect of grazing intensity on floristic and arthropod diversity over the four-year study. The two stocking rates did however result in a divergent evolution of legumes for which abundance increased at the high stocking rate (p<0.05). Abundance of Carabidae and grasshoppers from tall grasslands was higher at the moderate stocking rate (p<0.05). We conclude that decreasing stocking rate would only have a marginal effect on grassland biodiversity, while farm performance will be strongly affected by the decrease in the number of horses per unit area.

Governing nature by numbers — EU subsidy regulations do not capture the unique values of woody pastures

A vast majority of European farmers are dependent on EU subsidies, which makes subsidy regulations through the Common Agricultural Policy (CAP) powerful tools in shaping agricultural landscapes. Unfortunately, steering recommendations are sometimes arbitrary, like in the case of pasture management, where 50 trees per hectare constitute an upper limit to qualify for subsidies. Although pasture biodiversity is well studied and the core of many CAP conservation programmes, it is seldom studied as direct effects of subsidy systems. In this paper, we examine plant diversity in relation to the impact of subsidy systems in Swedish woody pastures along a gradient from 3 to 214 trees per hectare. We selected 64 sites where we recorded vascular plants, soil properties and canopy cover. We found a general increase in γ- and β-diversity along the gradient, whereas α-diversity and the number of grassland specialists remained indifferent along the gradient. Additionally, tree density, organic content and C:N-ratio were the strongest predictors of species composition. Hence, when CAP regulations encourage tree cutting for pastures to qualify for subsidies there is risk of homogenisation of EU grasslands, leading to decreased γ- and β-diversity. If a general target for the subsidies is to increase biodiversity, there is need to scrutinise these regulation details to preserve the high values of woody pastures. We argue that habitat variation, species diversity and low intensity management, rather than a specific number of trees, should be the main incentives for financial support to preserve biodiversity.

Flora of natural pasture near village Idjos as a indicator of habitat conditions

The natural and semi-natural pastures are highly endangered habitats in Serbia and the world and they are habitats of the unique flora and vegetation. Many of them are on the list of priority habitats for biodiversity conservation. Therefore, the starting point for the assessment, monitoring and conservation of biodiversity of pastures is to study the they flora and vegetation. These ecosystems are very sensitive to environmental conditions and anthropogenic influences, and the understanding of the relationship between plants and environmental factors is essential. The development of plants on a habitat depends of environmental factors, because they are excellent indicators of the habitat conditions. The aim of this paper is to assess the prevalent environmental conditions based on the ecological analysis of flora of natural pasture near village Iđos. This would assist its sustainable use and maintenance of its agricultural productivity, and also helped the recovery of this endangered natural ecosystem. The studied paature flora comprises 137 taxa (129 species, 7 subspecies and 1 variety). Based on the ecological analysis of the identified taxa, near village Iđos, the studied ecosystem - in temperate climate conditions (Kx= 3,18), on a soil characterized by considerable degree of salinity in places (S+ = 35,04%) - is moderately moisture (Fx = 2,80), neutral to mildly acidic (Rx = 3,26), moderately rich in nitrogen and nitrogen compounds (Nx = 3,05), and in organic compounds (Hx = 2,96), moderately aerated (Dx = 4,08), and subject to a favorable light (Lx = 3,80) and thermal regimen (Tx = 3,91).

Animal performances, pasture biodiversity and dairy product quality: How it works in contrasted mountain grazing systems

The interactions between botanical composition of pasture, quality of herbage grazed, performances of dairy cows and sensory and nutritional properties of dairy products were investigated using an integrated system approach. Two contrasting grazing systems were evaluated from May to September in two years. The treatments included a continuous grazing system (DIV) managed at a lenient stocking rate (1.0LUha−1) on a botanically-rich permanent pasture, and a rotational grazing system (PROD) set up at a higher stocking rate (1.7LUha−1) on a former temporary grassland presenting moderate biodiversity. DIV aimed to maximize biodiversity and obtain high sensory and nutritional quality cheese, whereas PROD was oriented towards milk production and herbage quality. In each system, 12 non-feed-supplemented Montbéliarde cows were used. The DIV system led to higher milk production per cow in the early grazing season than the PROD system (22.2 vs. 19.9kgd−1). At the beginning of summer, this milk production pattern was inverted following a decrease in grass nutritive value in the DIV system. In parallel, DIV cows showed a more marked loss of body condition than PROD cows over the season. In terms of milk fatty acid profile, the DIV system proved very interesting early in the grazing season but lost its value over time as the herbage matured. Cheese sensory properties differed between systems only after a long ripening period (6 months). Regarding the ecological performances, the DIV plot showed greater botanical and entomological biodiversity than the PROD plot. This study provides evidence that the balance between animal performances, dairy product quality and biodiversity in dairy systems is more complex than previously thought, since the expected benefits of each system vary markedly over periods. The evolution of herbage vegetation stage during the grazing season combined with the botanical composition of the pasture is a key component for understanding these variations.

Effects of type and size of gaps created by simulation of cattle activities on the recovery and similarity of vegetation community

AbstractCattle activities may affect pasture biodiversity and productivity. This study investigated the effects of type and size of gaps simulating cattle activities on the recovery and similarity of vegetation community in pastures. Two types of gaps (bare ground and mown vegetation as simulated trampling and grazing by animals, respectively) differing in size (20–100 cm in diameter) were artificially created in three vegetation communities (sown, aged sown and native pastures), and vegetation recovery in the gaps was monitored. Undisturbed patches (100 × 100 cm) were also monitored as a control. The similarity of botanical composition to the control was lowest in the 20 cm gaps, irrespective of the disturbance or vegetation types. Vegetation in the bare ground gaps tended to recover slower in 20 cm gaps than in 100 cm gaps in all vegetation types. Small gaps created by cattle activities may enhance vegetation species diversity while it may decrease productivity of pastures.

Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener) and beta (Jaccard and Magurran) biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing). Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

Differential responses of plants, reptiles and birds to grazing management, fertilizer and tree clearing

AbstractThe relative effects of tree clearing, increased livestock densities and nutrient enrichment have rarely been compared across markedly different organism types, but negative effects are generally predicted. In contrast, adoption of rotational grazing is thought to benefit biodiversity in pastures but there are few supporting data. We examined the response of native plants, birds and reptiles to livestock management in south‐eastern Australia. We selected 12 pairs of rotationally and continuously grazed farms. Two 1‐ha plots were established in native pastures on each farm, one cleared and the second still retaining woodland tree cover. Stocking rates, fertilizer histories and landscape tree cover varied among farms. The abundance and richness of all taxa was lower in cleared pastures. The less mobile organisms (reptiles and plants) were positively correlated with tree cover at landscape scales, but only when trees were present at the plot scale. This pattern was driven by a few observations in landscapes with approximately 50% tree canopy cover. Neither bird abundance nor richness was correlated with stocking rates or nutrient enrichment, but plant richness responded negatively to both. The response of reptiles varied, declining with nutrient enrichment but positively correlated with livestock densities. These responses may be partly interpreted within the context of prior filtering of species pools through long‐term grazing pressure. No taxa responded positively to rotational grazing management. We predict that reductions in livestock density and soil nutrients will directly benefit plants and less so reptiles, but not birds. Indirect benefits are predicted for birds and reptiles if management increases persistence of trees within paddocks. Although some forms of rotational grazing can increase woodland tree recruitment, rotational grazing in itself is unlikely to enhance diversity.

How do sheep affect plant communities and arthropod populations in temperate grasslands?

Grasslands being used in sheep farming systems are managed under a variety of agricultural production, recreational and conservational objectives. Although sheep grazing is rarely considered the best method for delivering conservation objectives in seminatural temperate grasslands, the literature does not provide unequivocal evidence on the impact of sheep grazing on pasture biodiversity. Our aim was therefore to review evidence of the impacts of stocking rate, grazing period and soil fertility on plant communities and arthropod populations in both mesotrophic grasslands typical of agriculturally improved areas and in native plant communities. We therefore conducted a literature search of articles published up to the end of the year 2010 using ‘sheep’ and ‘grazing’ as keywords, together with variables describing grassland management, plant community structure or arthropod taxa. The filtering process led to the selection of 48 articles, with 42 included in the stocking rate dataset, 9 in the grazing period dataset and 10 in the soil fertility dataset. The meta-analysis did not reveal any significant trends for plant species richness or plant community evenness along a wide stocking rate gradient. However, we found frequent shifts in functional groups or plant species abundance that could be explained by the functional properties of the plants in the community. The meta-analysis confirmed that increasing soil fertility decreased plant species richness. Despite the very limited dataset, plant species richness was significantly greater in autumn-grazed pastures than in ungrazed areas, which suggests that choosing an appropriate grazing period would be a promising option for preserving biodiversity in sheep farming systems. Qualitative review indicated that low grazing intensity had positive effects on Orthoptera, Hemiptera (especially phytophagous Auchenorrhyncha) and, despite a diverse range of feeding strategies, for the species richness of Coleoptera. Lepidoptera, which were favoured by more abundant flowering plants, also benefited from low grazing intensities. Spider abundance and species richness were higher in ungrazed than in grazed pastures. In contrast, there are insufficient published studies to draw any firm conclusions on the benefits of late grazing or stopping fertilization on insect diversity, and no grounds for including any of this information in decision support tools at this stage.

Grazing and climatic variability in Sajama National Park, Bolivia

Sajama National Park, the first protected area in Bolivia, includes five indigenous communities with a primary production base of pastoralism. The semi-arid region of the Central Andes is one of the most extreme areas of human occupation at 4200 meters altitude and affected by high climatic variability. This paper studies the relations between climate variability, resilience, biodiversity of pastures and pastoral production in Sajama National Park. We present a botanical study of palatable pasture herbs between two years, one humid (2006) and the other dry (2007). Thirty vascular plants were recorded. The number of species and the cover of iro (Festuca ortophylla) peak in areas of intermediate disturbance; areas that are at a medium distance from camelid corrals. On the other hand, the cover of ephemeral plants between tussocks increases in high disturbance areas. This is interpreted as a result of the tradeoff between the damage of grazing and the benefit of the fertilization produced by the herding animals. The local people clearly perceive strong impacts of climate change, combined with changes in management and human pressures. The social dynamics and production management, combined with climate warming, water reduction, and the increasing variability of surface water regimes create potential risks for the local sustainability of pastoralism.

Plant species diversity, ecosystem function, and pasture Management—A perspective

Grassland farmers face many challenges in pasture management including improving sustainability, reducing inputs of fertilizers and pesticides, and protecting soil resources. In this paper we provide our perspective on managing plant diversity within and among pastures as one tool to aid producers in meeting these challenges. Pasture ecosystems can be highly diverse, with a complex array of organisms contributing to ecosystem functioning. Within the broad range of plant and animal biodiversity in pastures, plant species diversity may be the most amenable to manipulation or management. Reported benefits of plant diversity in grasslands include: increased forage production, greater ecosystem stability in response to disturbance, and reduced invasion by exotic species such as weeds. Some view diversity as a sort of insurance policy where different species contribute in their own time or can take the place of species that fail from stress or mismanagement. Using mixtures of several forages in pastures, in some instances, can improve forage yield and reduce weed invasions. Pasture management for increased plant species diversity, however, is not simply mixing and planting as many forage species as possible. The kinds and amounts of different forage species along with their arrangement within and among pastures at the farm scale are critical features that must be considered. Tools must be developed to determine the appropriate species mixtures for varying soils, landscapes, climate and purposes to fulfill multiple functions for producers. Key words: Grazing ecosystem; forages; diversity; ecosystem function; ecosystem services