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1.
Although the process of reforestation of grassland has been widely studied in Europe, little is known about the effect of deforestation on grassland development. Thus, the specific objective of this study was to evaluate early changes in plant species composition, functional group, yield and biomass quality after deforestation of long‐term abandoned pastures. The experiment was established immediately after deforestation on sparse herbaceous vegetation (mean initial cover 27%) with the following treatments: grazing management only (G0), cutting and grazing aftermath (CG), grazing after seeding of grassland mixture (GS), grazing after a burning treatment in which branches were burned after deforestation (GB) and unmanaged control (U). Very rapid recovery of bare ground by germination and/or sprouting of grassland species was similar under all types of grazing management. Total plant species richness increased in all managed treatments except GB. Similarities according to redundancy analyses in plant species composition were found among G0, CG and GB treatments, especially for forbs with correlated rosette or creeping growth. The woody species, tall grasses and tall forbs had higher abundance in the U treatment. The restoration of grassland following deforestation of formerly reforested grassland area by grazing management was a relatively fast process, and swards were created after 3 years. The highest biomass yield was observed under treatments GS and GB. Forage quality of all managed treatments was sufficient for the demands of beef cattle grazing. However, for subsequent grassland preservation, some type of grazing management is necessary to prevent reforestation, which can occur immediately after deforestation in unmanaged places.  相似文献   

2.
Livestock grazing can be a means to maintain biodiversity in grasslands, but the outcome for vegetation structure and species composition depends on livestock type and grazing regime. This study aims at disentangling the effects of plant functional‐group abundance and livestock type on the above‐ and below‐ground biomass and N allocation in temperate pastures. We investigated the effects of cattle, sheep and mixed stocking on above‐ground biomass (AGB) and belowground biomass (BGB) and plant N pools in a replicated grazing experiment in two pasture community types with different plant functional‐group abundance (diverse vs. grass‐dominated swards). In the six treatments, AGB was reduced up to 80% compared with an ungrazed control. Cattle reduced AGB to a larger extent than sheep in diverse pastures (80 vs 44% reduction) while sheep grazing tended to do so in grass‐dominated pastures (57 vs 46% reduction); mixed stocking led to intermediate values. Grazing reduced AGB more than the N pool in AGB, thus lowering the biomass C/N ratio relative to the ungrazed control. Neither BGB nor the N pool in BGB differed between the grazing treatments and the control plots. We conclude that livestock type and functional‐group abundance are interacting factors that influence plant biomass and N pools in swards of managed temperate pastures. The contrasting biomass removal rates of cattle and sheep could be used to increase the structural heterogeneity and total plant species pool of pastures by keeping different livestock species in neighbouring patches.  相似文献   

3.
The plant species number and composition, iind yield of herbage biomass of an agriculturally improved hay meadow were assessed after 4 years under various combinations of grazing, fertilizer applicution. cutting date and seed addition treatments in a replicated split-plot design. Grazing treatments consisted of either autumn grazing with cattle and sheep, spring grazing with sheep or both regimes. Fertilizer application treatments consisted of either 25 kg ha?1 N plus 12–5 kg ha?1 P and K or no fertilizer. Cutting date treatments consisted of cuts on either 14 June, 2i July or 1 September. Seed addition treatments consisted of either no addition or sowing with a range of meadow species in the autumn. Data analysis was by correspondence analysis and analysis of variance. Species number decreased with fenilizer use and when the cutting date was 1 September. A range of species was affected by the main treatments and there were some first-order interactions, mainly between cutting date and fertilizer application. Rhinanthus minor was particularly favoured by the seed addition treatment. Species attnbutes in the regenerative and established phase were related to treatments and their effect on species composition. The National Vegetation Classification communities were associated with particular treatment regimes. The 21 July cutting date favoured ‘improved’ over ‘unimproved-traditional’ swards, with spring grazing favouring ‘unimproved-traditional’ swards. Lowest yields of herbage biomass were associated with autumn and spring grazing, the 14 June cutting date and no fenilizer treatments. The fenil-izer, 1 September cutting date and auiumn grazing treatments gave the highest yields. The implications of these results are discussed in terms of the conservation management required to return agriculturally improved mesotrophic grassland to a species composition similarto that of traditionally managed grassland.  相似文献   

4.
This study quantifies the impact of four different grazing regimes (heavy, moderate, light and ungrazed) on the vegetation dynamics of rangeland ecosystems along the southern boundary area of the Mu Us Desert, China. As the grazing intensities decreased, the soil quality, canopy cover, height, density, above‐ and below‐ground biomass, litter, root/shoot ratio and native plant (Aneurolepidium dasystachys) and grass abundances significantly increased; the above‐ground biomass of grasses increased, but the above‐ground biomass of forbs decreased. Ungrazed grassland has significantly improved from grasslands experiencing three other levels of grazing pressure, especially in the grassland biomass. Species richness increased as the grazing intensity decreased in the grazing grasslands, but peak species richness appeared under moderate and light grazing against lower productivity. Grazing exclusion causes desirable transitions in plant communities of desert steppe rangelands. Therefore, appropriate and efficient grazing exclusion is an available way to counteract local grassland degradation and promote rangeland sustainability.  相似文献   

5.
This study was conducted on a mixed‐grass prairie in south‐central North Dakota, USA, to test the effect of animal grazing on rhizome biomass. Below‐ground plant biomass samples were collected from pastures with moderate and heavy grazing by beef cattle. Because the biomass data did not meet the normality assumptions, the computer resampling method involving a nested anova was used. A reduction in rhizomes was found under heavy grazing, as compared with moderate grazing. Although rhizomes only accounted for a small fraction of total below‐ground plant biomass, our study suggested that the high rhizome density found in the moderately grazed pastures might be partly responsible for the greater potential of plant regrowth in the moderately grazed pastures than in the heavily grazed pastures on this mixed‐grass prairie.  相似文献   

6.
Semi‐natural temperate grasslands in Europe make an important contribution to biodiversity, but their existence has been endangered by both agricultural intensification and abandonment. In the Czech Republic, Arrhenatherion meadows are a typical example, with their conservation made difficult by the scarcity of research on effective management practices. We examined effects of two potentially useful approaches, application of 56 kg N ha?1 and earlier first mowing (i.e. in the middle of May, about 2 weeks earlier than usual), on species composition of an Arrhenatherion grassland in central Bohemia over a 7‐year period (1998–2004). These treatments did not influence species richness, but resulted in small changes in canopy structure in terms of cover of individual species and particular plant functional groups. N application resulted in increases in nitrophilous species and tall graminoids, especially Alopecurus pratensis, Festuca pratensis, Heracleum sphondylium and Ranunculus acris, and in decreases in short graminoids. Earlier mowing decreased tall herbs, especially H. sphondylium, and might thus be useful in compensating for increases in some nitrophilous species owing to N application. However, earlier mowing had negative impacts on spring‐flowering species in terms of reduced cover.  相似文献   

7.
Grassland in England and Wales accounts for nearly 60% of the enclosed agricultural land and approximately 50% is at least 20 years old. Botanical composition, especially amongst older grassland, is extremely variable.
A survey of 502 grassland farms was conducted in the 1970s. Factors affecting botanical composition of individual fields have been investigated using correlation and regression analyses and swards of similar botanical composition grouped using cluster analysis. Lolium perenne, Agrostis spp. and Holcus lanatus were numerically the most important species, contributing, on average, 35%. 21% and 10%, respectively. Most older swards contained Lolium perenne and Agrostis spp. in varying proportions depending on drainage, soil fertility and management. Swards containing a significant proportion of Trifolium repens were associated with adequate drainage, good soil nutrient status, low inputs of fertilizer nitrogen and hard grazing. Of the other common species Holcus lanatus was associated with poor drainage, low soil fertility, hay cutting, short-season grazing and low fertilizer N. Festuca rubra was mainly in older swards, at higher elevations and with low fertilizer N but heavy stocking. Swards containing Rumex spp., Poa trivialis and other sown grasses were associated with mowing together with reasonably high soil fertility.  相似文献   

8.
There is scope of increasing the nitrogen (N) efficiency of grazing cattle through manipulation of the energy and N concentrations in the herbage ingested. Because of asymmetric grazing by cattle between individual plant parts, it has not yet been established how this translates into the concentrations of N and water‐soluble carbohydrates (WSC) in the herbage ingested. A model is described with the objective of assessing the efficacy of individual tools in grassland management in manipulating the WSC and N concentrations of the herbage ingested by cattle under strip‐grazing management throughout the growing season. The model was calibrated and independently evaluated for early (April), mid‐ (June, regrowth phase) and late (September) parts of the growing season. There was a high correlation between predicted and observed WSC concentrations in the ingested herbage (R2 = 0·78, P < 0·001). The correlation between predicted and observed neutral‐detergent fibre (NDF) concentrations in the ingested herbage was lower (R2 = 0·49, P < 0·05) with a small absolute bias. Differences in the N concentration between laminae and sheaths, and between clean patches and fouled patches, were adequately simulated and it was concluded that the model could be used to assess the efficacy of grassland management tools for manipulating the WSC and N concentrations in the ingested herbage. Model application showed that reduced rates of application of N fertilizer and longer rotation lengths were effective tools for manipulating herbage quality in early and mid‐season. During the later part of the growing season, the large proportion of area affected by dung and urine reduced the effect of application rate of N fertilizer on herbage quality. In contrast, relative differences between high‐sugar and low‐sugar cultivars of perennial ryegrass were largest during this period. This suggests that high‐sugar cultivars may be an important tool in increasing N efficiency by cattle when risks of N losses to water bodies are largest. The model output showed that defoliation height affects the chemical composition of the ingested herbage of both the current and the subsequent grazing period.  相似文献   

9.
Changes in plant density were evaluated monthly in the first three vegetation seasons after imposing different grazing management treatments on abandoned semi‐natural grassland in the Czech Republic. There was no agricultural management in the 5 years before the start of the experiment in 1998. A completely randomized block experiment was established with the following five treatments: unmanaged control, intensive continuous grazing, extensive continuous grazing and a harvest in June followed by either intensive or extensive continuous grazing for the rest of the growing season. The sward was maintained at a target height of 5 and 10 cm under the intensive and extensive grazing managements respectively. An almost immediate increase in the densities of all sward components, especially grass tillers, occurred after the introduction of grazing on the previously abandoned grassland in comparison with the unmanaged control treatment. Trifolium repens was able to colonize and increase the number of its stolon growing‐points in all managed treatments, particularly in intensively grazed patches during the second and third experimental seasons. Delay to defoliation in both treatments containing a harvest in June resulted in an increase in the number of forb plants, particularly in the number of Taraxacum spp. plants, most probably due to an enabling of its seed production. It is evident that increases in plant density as a function of intensive defoliation are not restricted to the frequently documented effect on grass tillers but also can occur in many legume and forb species in species‐rich grasslands.  相似文献   

10.
The aim of this study was to determine the effects of different long‐term management options on re‐establishment of traditional species‐rich grassland in a Lolio‐Cynosuretum grassland. The experiment was set up in 1987 in a low‐fertilized mown pasture in the Eifel Mountains (Germany). Two and four cuts per year each with three levels of nitrogen fertilizer application were compared to no application of P and K fertilizer. Biomass production increased as a result of N application, whereas crude protein content and digestibility of organic matter improved in the four‐cut treatments. During a 20‐year period, we found a significant shift in dominant grass species without any significant effect on species richness. Lolium perenne and Elytrigia repens were replaced by Holcus lanatus and Alopecurus pratensis, especially in the two‐cut treatments with N application. In the unfertilized plots, several individuals of Platanthera bifolia appeared when swards were cut only twice per year, probably as a result of nutrient depletion together with low cutting frequency. An increase in number of cuts mainly supported plant species well adapted to intensive management, even under low N application and relatively low plant‐available P content in the soil. Therefore, we conclude that cutting frequency was a key driver on plant species composition in this experiment. The re‐establishment of traditional species‐rich grassland from intensively managed Lolio‐Cynosuretum was not achieved within 20 years of cutting management combined with absence of P and K application.  相似文献   

11.
Dandelion (Taraxacum officinale agg.) is a common forb species in grasslands in Europe. Although sometimes regarded as a valuable forage herb, it may become a weed, especially in arable land. There is limited information on the response of Taraxacum to long‐term grassland management practices. Therefore, we analysed cover and dry‐matter standing biomass of Taraxacum in a long‐term (1998–2012) grazing experiment on an Agrostis capillaris grassland. The following treatments were laid out on formerly abandoned grassland: (i) intensive grazing (IG); (ii) extensive grazing (EG); (iii) first cut followed by intensive grazing (ICG); (iv) first cut followed by extensive grazing (ECG); and (v) unmanaged grassland (U). During the first 10 years, all defoliation treatments (i–iv) supported the presence of Taraxacum, and the lowest proportion was recorded in the unmanaged treatment (U). During the final 7 years of the study, combined cutting and grazing promoted Taraxacum cover more than that of grazing only (ICG > IG > ECG > EG). Cover of Taraxacum was negatively affected by increasing sward height where Taraxacum plants had lower fitness. Due to the relatively strong relationship between percentage cover of Taraxacum and its dry‐matter biomass, percentage cover could be used as a simple method for the assessment of biomass of Taraxacum in a sward. Results are discussed in the context of adapting the management of A. capillaris grassland as a simple method for control of Taraxacum abundance, particularly in situations of extensification or abandonment.  相似文献   

12.
Systemic‐ and seed‐transmitted fungal endophytes are suggested to enhance competitive dominance of agronomic grasses by increasing plant growth and defence against herbivores. We studied whether Neotyphodium uncinatum endophyte infection frequencies of meadow fescue (Schedonorus pratensis) and botanical composition of pastures are affected by 4, 5, 7 and 21 years of grazing by dairy cattle. We then examined with one greenhouse and two field experiments, whether endophyte infection and clipping affect regrowth of young or mature plants relative to nutrient availability in soil. The frequencies of infected plants and the number of plant species were less in grazed parts of the pastures. Endophytes significantly reduced relative regrowth and dry biomass of regrowth of the grass irrespective of nutrient levels in a 1‐year‐old field (on an average 18% in 2 months) and under high nutrient conditions in the greenhouse experiment (on an average 3% in 3 months) respectively. However, effects of endophytes were not detected in 5‐year‐old fields and under low nutrient conditions in the greenhouse. In contrast to past studies, our results demonstrate that grazing may negatively affect endophyte–grass symbiosis and number of plant species of successional pastures, and suggest that the effects of endophytes may be linked to the ontogeny of the host.  相似文献   

13.
We compared the role of grasses and forbs in managed grassland under nutrient‐poor conditions via the experimental removal of one of these two species groups and an evaluation of the removal effects over a 5‐year chronosequence (beginning 4 years after removal start), focusing on above‐ground biomass and community composition. There was evidence for the complementarity of grasses and forbs, as shown by better relative performance of both groups in the mixture, measured as the proportional deviation of their above‐ground biomass from that predicted using single‐group plots. Relative performance of forbs was better than that of grasses and did not change significantly throughout the experiment. Relative performance of grasses decreased, reaching a minimum value of 0·03, but then increased to 0·71, in parallel with increasing legume proportion in the above‐ground biomass (from 0·9 to 5·1%). The botanical composition of the grass group did not respond to forb removal. Among the forbs, subordinate species sensitive to light competition became more abundant after removal of grasses; the forb species richness increased on average by 1·6 species per plot. Our results show that the composition and diversity of the forb group is affected by the presence of grasses, and the presence of forbs in a grassland community assures higher temporal stability in above‐ground production. Under increasing depletion of soil nutrients, the grasses derive substantial benefits from the presence of legume species and possibly also from the other forb species. The study supports the need for realistic, long‐term experiments to better understand plant community dynamics.  相似文献   

14.
The present study investigated how the abundance and sexual reproduction of herbs and grasses relates to the presence of shrubs of Rosa dumalis in three semi‐natural pastures in Sweden. Shrubs may affect grassland plants negatively by competition, positively by serving as grazing refuge, or neutrally. At different distances from shrubs of R. dumalis, data were collected on plant abundance, frequency of reproductive shoots, vegetation height and litter depth. In one grassland, data were collected on seedling density and frequency of reproductive shoots in the presence and absence of grazing. The shrubs functioned as grazing refuges with taller vegetation, deeper litter and higher probability of reproduction by plants. The overall number of plant species remained the same at all distances from shrubs. Most species showed a neutral relationship with shrubs. Proportionately, 0·08–0·26 of the species showed a negative pattern to shrubs and 0·14–0·30 a positive pattern. Seedling density was negatively correlated with litter depth and peaked at 60–90 cm from shrubs. Establishment of seedlings of small‐seeded species was negatively related to shrubs probably because of thicker litter layer close to shrubs. The observed patterns were compared with different functional traits, such as Ellenberg values, plant height, growth form and Raunkiaer life form. Plant height from data in the literature was the trait that best explained the relationship of plant species to shrubs because tall species were more common in proximity to shrubs. It was concluded that shrubs increase the heterogeneity in grasslands and that intensive shrub‐clearing may negatively affect biodiversity.  相似文献   

15.
Artificial grassland establishment has been implemented in the alpine region of Qinghai–Tibetan Plateau in China as a mitigation tool against grassland degradation, one of the major environmental problems in this region. We hypothesized that both grassland degradation and artificial restoration may alter the reproductive modes of the alpine vegetation at the levels of individual species as well as plant functional groups. By investigating a long-term field study of grassland degradation and artificial restoration experiments, we found that alpine plants can maintain a highly plastic relationship between sexual and asexual reproduction, that is, the alpine plants in degraded grasslands increased their efforts towards sexual reproduction while those in artificially restored grasslands promoted their efforts in vegetative reproduction with in the year after restoration. The high reproductive plasticity of the alpine plants can be regulated through a number of mechanisms, which include changing proportion of clonal species in the plant composition, altering number ratio of sexual and vegetative propagules, shifting biomass allocation for sexual and vegetative reproduction at both individual species and functional group levels. These conclusions demonstrate how crucial it is to consider manipulation of reproductive modes needed to restore the structure and stability of degraded alpine grasslands.  相似文献   

16.
The impact of deferred grazing (no defoliation of pastures for a period generally from spring to autumn) and fertilizer application on plant population density, ground cover and soil moisture in a hill pasture (annual grass dominated, with Australian native grasses being the major perennial species) were studied in a large‐scale field experiment from 2002 to 2006 in southern Australia. Three deferred grazing strategies were used: short‐term deferred grazing (no defoliation between October and January each year), long‐term deferred grazing (no defoliation from October to the autumn break, that is the first significant rainfall event of the winter growing season) and optimized deferred grazing (withholding time from grazing depends on morphological development of the plants). These treatments were applied with two fertilizer levels (nil fertilizer and 50 kg P ha?1 plus lime) and two additional treatments [continuous grazing (control) and no grazing for year 1]. Deferred grazing increased (P < 0·05) perennial grass tiller density compared with the control. On average, the tiller density of the three deferred grazing treatments was 27–88% higher than the control. There was a negative (P < 0·01) relationship between perennial and annual grass tiller density. Fertilizer application increased (P < 0·05) legume plant density. The densities of annual grasses, legumes, onion grass (Romulea rosea) and broadleaf weeds varied between years, but perennial grass density and moss cover did not. The ground cover of the deferred grazing treatments in autumn was on average 27% higher than the control. Soil moisture differed between treatments at 15–30 cm depth, but not at 0–15 depth over autumn and winter. The results imply that deferred grazing can be an effective tool for rejuvenating degraded native pastures through increases in native grass tiller density and population and through improving farm productivity and sustainability.  相似文献   

17.
The results are reported from an experiment on the effects of cutting date (14 June, 21 July and I September), fertilizer application (none or 80 kg ha?1 N plus 40 kg ha?1 P and K) and grazing treatments (none, autumn or autumn plus spring) on the vegetation of an upland mesotrophic grassland in Upper Teesdale. northern England, UK. Effects on plant species number and cover are reported for 4 years (1989–93) of treatment. Effects on ‘species -attributes’ are given for the fourth year. The cessation of grazing combined with the use of fertilizer progressively reduced species number by about 25%. Under traditional management (no fertilizer, cutting date on 21 July, autumn and spring grazing) the species number and cover remained relatively static over the 4 years. Comparison between treatments in the fourth year showed a reduction in species number under the fertilizer application, cutting date on 1 September and no-grazing treatments. Fertilizer use together with cutting date on 1 September particularly lowered species number and cover. Analysis of variance was used to assess the effect of treatment on species that occurred frequently in the sward. A cutting date of 1 September favoured Agrostis capillaris. Alopecurus pratensis, Poa trivialis, Phleum pratense and Trisetum flavescens, The absence of grazing favoured Dactylis glomerata and Holcus lanatus. The use of fertilizer particularly favoured A. pratensis and H. lanatus. Ordination methods were used to assess the effect of treatment on the less frequent species. These were primarily associated with the treatment combination that matched ‘traditional’ management. Deviations from this ‘traditional’ regime acted separately, rather than in combination, and favoured different grass species. Traditional management was associated with ruderal, stress-tolerant ruderal and competitive ruderal strategists and with longer seed germination times, heavier seeds, some of which needed scarifying or chilling to break dormancy, and transient seed banks that germinated in the autumn. The original sward was an Anthoxanthum odora-turn-Geranium sylvatirum grassland, Briza media subcommunity (MG3b). After 4 years, Festuca ovina-Agrostis capillaris-Galium saxatile grassland, Holcus lanatus-Trifolium repens subcom-munity (U4b) and Lolium perenne-Alopecurus pratensis-Festuca pratensis grassland (MG7c) were found in many of the fertilized and late-cutting treatments.  相似文献   

18.
Understanding the relationships between farmers' land‐use and management decisions, and plant diversity is a challenge. It requires characterization of plant diversity within and between fields and investigation of land‐use allocation to fields. To analyse how grassland functional composition [mean plant trait and functional diversity index (FD)] varies according to scale (field, land‐use type: cutting, grazing, farm), grasslands were characterized according to leaf dry‐matter content (leaf DM) and FD computed from leaf DM values. A leaf DM‐αFD framework was used to analyse how leaf DM‐based plant strategies were distributed at land‐use type and farm scales (βFD). The study was conducted on eight dairy and beef farms (169 grasslands) differing in their stocking rate. At field and land‐use type scales, leaf DM was significantly decreased and increased with N fertilizer rate and field elevation respectively. It was significantly higher for grazing than for cutting. At the farm scale, the main differences between farms resulted from differences in plant strategy distribution between land‐use types within a farm and among farms for a given land‐use type in relation to management intensity. Farms that contributed the most to αFD had the highest stocking rate, and those which had the most contrasting grasslands for management intensity had the highest βFD. Management practices need to be examined at a land‐use type scale for evaluating the within‐ and between‐field plant functional compositions. By contrast, the value of the analysis was reduced if data were collected and averaged at the farm scale.  相似文献   

19.
Reduction of grazing intensity and the use of traditional instead of commercial breeds has frequently been recommended to meet biodiversity and production goals in sustainable grazing systems in Europe. To test the impact of such practices across a range of contrasting grassland types, integrated measurements of foraging behaviour, agronomic production and botanical, structural and invertebrate biodiversity were made over three years on four sites in the UK, Germany, France and Italy. The sites in the UK and Germany were mesotrophic grassland with high productivity and low to moderate initial levels of plant diversity, and were grazed by cattle. The French site was a semi‐natural, species‐rich grassland grazed by cattle. The Italian site contained a wider range in plant diversity, from species‐rich to mesotrophic grassland, and was grazed by sheep. The treatments were: MC, moderate grazing intensity with a commercial breed – this was designed to utilize herbage growth for optimum livestock production; LC, lenient grazing intensity with a commercial breed – this was designed to increase biodiversity by not fully utilizing herbage growth; and LT, lenient grazing intensity with a traditional breed – this was also designed to increase biodiversity. Neither fertilizers nor pesticides were applied. The nutritive value of the herbage and the performance of the livestock were measured. Mean stocking rates were proportionately 0·30–0·40 lower and mean sward heights and herbage mass on offer were 0·30–0·50 higher on the LC and LT treatments compared with the MC treatment. The proportion of live and dead material, and leaves and stems in the herbage, its chemical composition and nutritive value were little affected by the treatments. Individual livestock performance, measured as liveweight gain, showed no consistent response to treatment. In Germany, performance on the MC treatment was slightly lower than on the LC and LT treatments but no such difference was found on the sites in the other countries. Livestock breed did not have a strong effect on livestock performance. In the UK and France the traditional breeds had a lower performance but this was not the case in Germany or Italy. Livestock performance per ha of the LC and LT treatments was up to 0·40 lower than of the MC treatment. It is concluded that biodiversity‐targeted extensive grazing systems have potential to be integrated into intensive livestock production systems because the individual livestock performance reaches a similar level compared to a moderate grazing intensity. Traditional breeds did not have a production advantage over commercial breeds on extensively managed pastures.  相似文献   

20.
To maintain biodiversity in semi‐natural grasslands, the choice of breed of livestock and season of grazing can be important. The objective was to determine the effects of breed and season on the composition of plant fragments in the faeces of cattle grazing a heterogeneous semi‐natural grassland. Twelve heifers of the traditional Swedish Väneko breed (live weight 309 kg) and twelve heifers of the Charolais breed (live weight 431 kg) were allocated to three pastures per breed. Faeces samples were collected in spring, summer and autumn for micro‐histological examination of plant fragments. On the same occasion, defoliation of four competitive plant species was recorded. Faecal plant fragments mainly consisted of grasses but also herbs, whereas Cyperaceae, despite their abundance on the pastures, only composed a small proportion of fragments. Season affected the composition of plant fragments in the faeces, with a higher proportion of Cyperaceae and herbs in spring than later in the grazing period (P < 0·001), and the heifers ingesting more grasses and woody plants in autumn. In spite of a clear difference in live weight between the two breeds, no effects of breed on the composition of plant fragments in faeces were observed, although Väneko heifers defoliated more Filipendula ulmaria in spring than the Charolais heifers (P < 0·01). In addition, defoliation of Alnus glutinosa increased later in the grazing period (P < 0·05), especially for the Väneko heifers, indicating control of pernicious brushwood by grazing may be more effective in autumn.  相似文献   

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