Understanding the spatiotemporal patterns of the forage-livestock balance is imperative for regionally arranging animal husbandry production while ensuring sustainable grassland-ecosystem service use.The Xilin Gol ste...Understanding the spatiotemporal patterns of the forage-livestock balance is imperative for regionally arranging animal husbandry production while ensuring sustainable grassland-ecosystem service use.The Xilin Gol steppe is an important native grassland resource in Inner Mongolia Autonomous Region,China.This study aimed to elucidate the dynamics of the forage-livestock balance in the Xilin Gol steppe during the period 2000–2015.We evaluated the forage production and corresponding livestock carrying capacity(LCC)in the growing seasons of 2000–2015 using remote sensing data and field surveys.The spatiotemporal patterns of the forage-livestock balance were then assessed at regional,city(including city,county and banner),and village scales using statistical and household survey data.The results showed that both forage production and LCC decreased in the Xilin Gol steppe from east to west.During the period 2000–2015,the regional average forage production and corresponding LCC fluctuated without following a distinct trend,but were consistent with the variations in precipitation.The forage-livestock balance varied with time,space,and scale.At the regional scale,steppes were overgrazed in the early 2000s,but a forage-livestock balance or even grazing potential was achieved in other years.At the city scale,approximately half of the region exhibited a"forage-livestock balance"since 2000.However,about half of the region still experienced overgrazing,which mainly located in the southwest sandy zones.Such changes may have been affected by the variations in grassland quality,forage production,compensation payment,and so on.We suggest a location-specific management scheme for grazing constraints,ecological compensation payment,and industry development to aid in harmonizing animal husbandry and environmental restoration,while promoting sustainable development goals by 2030.展开更多
An in vitro rumen gas production technique was employed to determine the methane production and fermentation characteristics of Leymus chinensis and Medicago ruthenica at differing harvest dates(May 15,May 30,June 30...An in vitro rumen gas production technique was employed to determine the methane production and fermentation characteristics of Leymus chinensis and Medicago ruthenica at differing harvest dates(May 15,May 30,June 30,July 30,August 30 and September 30),which are sequential phases within a single continuous growth of two 10-year-old pastures.To quantify the rate of degradation and compare in vitro rumen fermentation characteristic,a logistic-exponential model,where initial gas volume was zero(LE_0),was used to fit gas production and methane output results.Dried,milled forage samples were incubated in vitro for 72 h at 39℃ and gas production was recorded intermittently throughout the incubation and gas samples were collected to measure methane production.Results showed that there were significant interactions between species and harvest for all chemical composition variables(P〈0.001) and condensed tannin content(P〈0.001).L.chinensis produced more total gas and methane than M.ruthenica(P〈0.001).Both total gas and methane production decreased lineally(P〈0.001) with advancing harvest date.The degradation rates of L.chinensis and M.ruthenica harvested on September 30 were lower than those on the other harvest dates(P〈0.01).M.ruthenica fermented fluid had higher concentration of ammonia N(P〈0.05) and molar proportions of isobutyrate(P〈0.01),valerate(P〈0.001) and isovalerate(P〈0.01) in total volatile fatty acids than L chinensis.Furthermore,concentration of isovalerate decreased cubically with advancing harvest date(P〈0.05).In conclusion,M.ruthenica produced less methane than L.chinensis and the total gas and methane production decreased with advancing harvest date for both species,which may be due to the changes in contents of chemical compositions and condensed tannin in forages.展开更多
The increase of probability and depth of weather anomalies, which is important characteristic of climate change process, leads to higher risk of loss of perennial grasses forage yield, rise of price volatility on fora...The increase of probability and depth of weather anomalies, which is important characteristic of climate change process, leads to higher risk of loss of perennial grasses forage yield, rise of price volatility on forage grain market. Increase of sustainability of dairy production supposes development of adapted to new weather conditions technologies of forage production, which are characterized by different investment and current costs. It generates a need of economic evaluation and comparative analysis of technologies taking into account climate change forecast and need of sustainable forage production guarantee. Purpose of the research project is the development of approaches to assessing adaptive technologies in forage production, increasing of dairy farming sustainability to changes in the external environment, including climate change. We assessed changes in forage production technologies in the Leningrad region of Russia, analyzed the implications of these changes for production and financial performance of dairy farming, proposed and tested methods for determination of the optimum harvesting time of perennial grasses. Special attention is paid to the long-term effects of changing the structure of cows' diet--shortening the productive use of animals, which reduces the efficiency of dairy herd use and limits the possibility of expanded reproduction. The primary method of the study is the analysis of milk production statistics in the Leningrad region and the Russian Federation. As a result of the study, the necessity to improve the production and investment planning quality, as well as the use of forecasts during planning of dairy production, is grounded.展开更多
Monitoring of rangeland forage production at specified spatial and temporal scales is necessary for grazing management and also for implementation of rehabilitation projects in rangelands. This study focused on the ca...Monitoring of rangeland forage production at specified spatial and temporal scales is necessary for grazing management and also for implementation of rehabilitation projects in rangelands. This study focused on the capability of a generalized regression neural network(GRNN) model combined with GIS techniques to explore the impact of climate change on rangeland forage production. Specifically, a dataset of 115 monitored records of forage production were collected from 16 rangeland sites during the period 1998–2007 in Isfahan Province, Central Iran. Neural network models were designed using the monitored forage production values and available environmental data(including climate and topography data), and the performance of each network model was assessed using the mean estimation error(MEE), model efficiency factor(MEF), and correlation coefficient(r). The best neural network model was then selected and further applied to predict the forage production of rangelands in the future(in 2030 and 2080) under A1 B climate change scenario using Hadley Centre coupled model. The present and future forage production maps were also produced. Rangeland forage production exhibited strong correlations with environmental factors, such as slope, elevation, aspect and annual temperature. The present forage production in the study area varied from 25.6 to 574.1 kg/hm^2. Under climate change scenario, the annual temperature was predicted to increase and the annual precipitation was predicted to decrease. The prediction maps of forage production in the future indicated that the area with low level of forage production(0–100 kg/hm^2) will increase while the areas with moderate, moderately high and high levels of forage production(≥100 kg/hm^2) will decrease both in 2030 and in 2080, which may be attributable to the increasing annual temperature and decreasing annual precipitation. It was predicted that forage production of rangelands will decrease in the next couple of decades, especially in the western and southern parts of Isfahan Province. These changes are more pronounced in elevations between 2200 and 2900 m. Therefore, rangeland managers have to cope with these changes by holistic management approaches through mitigation and human adaptations.展开更多
Animal husbandry and crop farming are specialized for development in separate areas on the Tibetan Plateau. Such a pattern of isolation has led to current concerns of rangeland and farming system degradation due to in...Animal husbandry and crop farming are specialized for development in separate areas on the Tibetan Plateau. Such a pattern of isolation has led to current concerns of rangeland and farming system degradation due to intensive land use. The crop-livestock integration, however, has been proven to increase food and feed productivity thorough niche complementarity, and is thereby especially effective for promoting ecosystem resilience. Regional synergy has emerged as an integrated approach to reconcile rangeland livestock with forage crop production. It moves beyond the specialized sectors of animal husbandry and intensive agriculture to coordinate them through regional coupling. Therefore, crop-livestock integration(CLI) has been suggested as one of the effective solutions to forage deficit and livestock production in grazing systems. But it is imperative that CLI moves forward from the farm level to the regional scale, in order to secure regional synergism during agro-pastoral development. The national key R & D program, Technology and Demonstration of Recovery and Restoration of Degraded Alpine Ecosystems on the Tibetan Plateau, aims to solve the problems of alpine grassland degradation by building up a grass-based animal husbandry technology system that includes synergizing forage production and ecological functioning, reconciling the relationship between ecology, forage production and animal husbandry, and achieving the win-win goals of curbing grassland degradation and changing the development mode of animal husbandry. It is imperative to call for regional synergy through integrating ecological functioning with ecosystem services, given the alarming threat of rangeland degradation on the Tibetan Plateau. The series of papers in this issue, together with those published previously, provide a collection of rangeland ecology and management studies in an effort to ensure the sustainable use and management of the alpine ecosystems.展开更多
This research was aimed to evaluate the productivity of native pasture in Timor Island by introducing various palatable species.The study was carried out on native pasture in Tuatuka,Timor Island for seven months.The ...This research was aimed to evaluate the productivity of native pasture in Timor Island by introducing various palatable species.The study was carried out on native pasture in Tuatuka,Timor Island for seven months.The study was performed by using randomized block design(RBD)with eight treatments(S0:no introduction,S1:Cynodon dactilon,S2:Dicanthium aristatum,S3:C.plectotachyus,S4:Brachiaria decumbens,S5:Desmanthus virgatus,S6:Macroptilium atropurpureum,S7:Clitoria ternatea)with four replications.Procedures on this study include trial plots preparation,tillers preparation for each species,introduction of species in trial plots,maintenance and observation of the productivity.Variables observed were forage production(fresh and dry matter(DM)in ton/ha),nutrient content(%)and stock capacity(animal unit(AU)/ha).Data were analyzed for variance based on RBD and followed by Duncan’s test.Analysis of variance showed that introduction of species had a very significant effect(p<0.01)on all observed variables.The introduction of M.atropurpureum produced the highest fresh forage(2.1 t/ha)and DM production(0.69 t/ha).M.atropurpureum also had the highest DM content(43.61%),nitrogen free extract(52.52%)and stock capacity(1.06 AU/ha).The highest crude protein and crude fiber content were found in D.virgatus(4.31%and 36.62%).The highest extract ether was observed in D.aristatum(1.48%).No introduction had the lowest productivity,but demonstrated the highest ash content.The introduction of palatable species increased the productivity of native pasture in Timor and M.atropupureum was the best introduced species.展开更多
Determining biomass production of individual alfalfa (Medicago sativa L.) plants in space planted evaluation studies is generally not feasible. Clipping plants is time consuming, expensive, and often not possible if t...Determining biomass production of individual alfalfa (Medicago sativa L.) plants in space planted evaluation studies is generally not feasible. Clipping plants is time consuming, expensive, and often not possible if the plants are subjected to grazing. A regression function (B′ = 0.72558 + 0.11638 × V′) was developed from spaced plants growing on rangeland in northwestern South Dakota near Buffalo to nondestructively estimate individual plant biomass (B) from canopy volume (V). However, external validation is necessary to effectively apply the model to other environments. In the summer of 2015, new data to validate the model were collected from spaced plants near Brookings, South Dakota. Canopy volume and clipped plant biomass were obtained from ten alfalfa populations varying in genetic background, growth habit, and growth stage. Fitted models for the model-building and validation data sets had similar estimated regression coefficients and attributes. Mean squared prediction errors (MSPR) were similar to or smaller than error mean square (MSE) of the model-building regression model, indicating reasonable predictive ability. Validation results indicated that the model reliably estimated biomass of plants in another environment. However, the technique should not be utilized where individual plants are not easily distinguished, such as alfalfa monocultures. Estimating biomass from canopy volume values that are extrapolations (>2.077 × 10<sup>6</sup> cm<sup>3</sup>) of the model-building data set is not recommended.展开更多
Background:More frequent and severe drought events due to climate change pose a major challenge for sustainable forage production in managed grasslands.This study investigated whether multispecies grassland communitie...Background:More frequent and severe drought events due to climate change pose a major challenge for sustainable forage production in managed grasslands.This study investigated whether multispecies grassland communities can provide greater resistance to and/or recovery from drought compared to monoculture communities.Methods:Mesocosms of Lolium perenne L.,Cichorium intybus L.,Trifolium repens L.and Trifolium pratense L.were established as monocultures,and a four-species mixture.A drought gradient with five levels of water supply ranging from a mild to a severe treatment was applied for 10 weeks,in each of 2 years.Shoot biomass was harvested to assess drought resistance,drought recovery and annual yields.Root mass density and specific root length were measured in Year 2.Results:Across the drought gradient,four-species communities had significantly larger annual yields than each of the four monocultures,indicating transgressive overyielding.This was despite relatively low drought resistance for four-species communities compared with L.perenne and C.intybus monocultures.Recovery of yields following drought was high for all communities.Conclusions:Multispecies swards with complementary traits can provide a viable adaptation option across a wide range of drought severities.Application of a stress gradient methodology allowed a more detailed understanding of stress responses.展开更多
Aims Research on the effects of extreme rainfall events on ecosystem function has primarily focussed on drought or flooding events,which usually include changes to mean or total rainfall,annually or over a season.Howe...Aims Research on the effects of extreme rainfall events on ecosystem function has primarily focussed on drought or flooding events,which usually include changes to mean or total rainfall,annually or over a season.However,less is known about the effects of increased rainfall variability without change to mean or total amounts.We investigated the effects of increased variation of water supply on shoot and root biomass as well as the distribution of root biomass of four grassland plant species,grown in monoculture and mixture communities.Methods Perennial ryegrass(Lolium perenne L.,shallow-rooting grass),chicory(Cichorium intybus L.,deep-rooting forb),white clover(Trifolium repens L.,shallow-rooting legume)and red clover(Trifolium pratense L.,deep-rooting legume)were established in mesocosms.Four plants of the same species were grown in monoculture communities and one of each species grown in four-species communities.Water supply was manipulated such that;compared with a baseline level with low variation in water supply,there was a treatment with medium variation(±40%)and another with high variation(±80%).Shoot and root biomass were measured,and vertical root distribution models fitted.Important Findings Compared with the low variation treatment,shoot biomass was significantly reduced under high variation for white clover,red clover and four-species communities.Under all conditions,four-species communities produced more shoot and root biomass than predicted by species performance in monoculture(overyielding).Under increased water variation,chicory monocultures allocated a higher proportion of root biomass to deeper soil layers while the total root biomass of white clover monocultures was significantly reduced.These results indicate that increased variability of water supply can negatively affect the shoot and root biomass production of single and multi-species grasslands.There is a need for further investigation of water variation effects on the functioning of multi-species grassland systems at field scale.展开更多
Crop-livestock integration(CLI)is a significant practice for livestock grazing systems in alpine rangelands.It offers the potential to achieve sustainable crop and livestock production.However,the separate crop and li...Crop-livestock integration(CLI)is a significant practice for livestock grazing systems in alpine rangelands.It offers the potential to achieve sustainable crop and livestock production.However,the separate crop and livestock systems that exist today have led to issues of intensive agriculture,rangeland degradation and forage shortage in the Tibetan Plateau.Developing crop-livestock integration through sown pastures can be an effective way to lift pasture productivity and improve livestock production.Thus,to explore the potential for integrating crop and livestock production in alpine grazing systems,an assessment of potential forage and livestock production using multiple datasets was carried out in Burang County,China.Results showed the marginal land potentially available for sown pastures was about 560 ha,located mostly in the Burang township of the Karnali basin.Accumulated temperature was the dominant limiting factor for establishing sown pastures,therefore cold tolerance of forage species and growth period should be taken into consideration.Furthermore,the number of livestock decreased during the period 2012–2016;yet often,the number of livestock in rangeland landscape was greater than that in agro-pastoral landscape.The average number of livestock was about 110000 standard sheep units(SU)in the study area,but forage from sown pastures and crop residues could potentially feed about 11000 SU,accounting for 50%of the livestock population in the Karnali basin.We found that integrating crop and forage production could fill feed gaps for grazing systems,particularly in the agro-pastoral landscape of the Karnali basin.The results of this study provide scientific support to guide future forage production and to promote further crop and livestock integration in Burang County.展开更多
基金the National Natural Science Foundation of China(41971130)。
文摘Understanding the spatiotemporal patterns of the forage-livestock balance is imperative for regionally arranging animal husbandry production while ensuring sustainable grassland-ecosystem service use.The Xilin Gol steppe is an important native grassland resource in Inner Mongolia Autonomous Region,China.This study aimed to elucidate the dynamics of the forage-livestock balance in the Xilin Gol steppe during the period 2000–2015.We evaluated the forage production and corresponding livestock carrying capacity(LCC)in the growing seasons of 2000–2015 using remote sensing data and field surveys.The spatiotemporal patterns of the forage-livestock balance were then assessed at regional,city(including city,county and banner),and village scales using statistical and household survey data.The results showed that both forage production and LCC decreased in the Xilin Gol steppe from east to west.During the period 2000–2015,the regional average forage production and corresponding LCC fluctuated without following a distinct trend,but were consistent with the variations in precipitation.The forage-livestock balance varied with time,space,and scale.At the regional scale,steppes were overgrazed in the early 2000s,but a forage-livestock balance or even grazing potential was achieved in other years.At the city scale,approximately half of the region exhibited a"forage-livestock balance"since 2000.However,about half of the region still experienced overgrazing,which mainly located in the southwest sandy zones.Such changes may have been affected by the variations in grassland quality,forage production,compensation payment,and so on.We suggest a location-specific management scheme for grazing constraints,ecological compensation payment,and industry development to aid in harmonizing animal husbandry and environmental restoration,while promoting sustainable development goals by 2030.
基金support of the NationalNatural Science Foundation of China(31201820)the Excellent Young Scientists Foundation of the Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun,China(DLSYQ12008)
文摘An in vitro rumen gas production technique was employed to determine the methane production and fermentation characteristics of Leymus chinensis and Medicago ruthenica at differing harvest dates(May 15,May 30,June 30,July 30,August 30 and September 30),which are sequential phases within a single continuous growth of two 10-year-old pastures.To quantify the rate of degradation and compare in vitro rumen fermentation characteristic,a logistic-exponential model,where initial gas volume was zero(LE_0),was used to fit gas production and methane output results.Dried,milled forage samples were incubated in vitro for 72 h at 39℃ and gas production was recorded intermittently throughout the incubation and gas samples were collected to measure methane production.Results showed that there were significant interactions between species and harvest for all chemical composition variables(P〈0.001) and condensed tannin content(P〈0.001).L.chinensis produced more total gas and methane than M.ruthenica(P〈0.001).Both total gas and methane production decreased lineally(P〈0.001) with advancing harvest date.The degradation rates of L.chinensis and M.ruthenica harvested on September 30 were lower than those on the other harvest dates(P〈0.01).M.ruthenica fermented fluid had higher concentration of ammonia N(P〈0.05) and molar proportions of isobutyrate(P〈0.01),valerate(P〈0.001) and isovalerate(P〈0.01) in total volatile fatty acids than L chinensis.Furthermore,concentration of isovalerate decreased cubically with advancing harvest date(P〈0.05).In conclusion,M.ruthenica produced less methane than L.chinensis and the total gas and methane production decreased with advancing harvest date for both species,which may be due to the changes in contents of chemical compositions and condensed tannin in forages.
文摘The increase of probability and depth of weather anomalies, which is important characteristic of climate change process, leads to higher risk of loss of perennial grasses forage yield, rise of price volatility on forage grain market. Increase of sustainability of dairy production supposes development of adapted to new weather conditions technologies of forage production, which are characterized by different investment and current costs. It generates a need of economic evaluation and comparative analysis of technologies taking into account climate change forecast and need of sustainable forage production guarantee. Purpose of the research project is the development of approaches to assessing adaptive technologies in forage production, increasing of dairy farming sustainability to changes in the external environment, including climate change. We assessed changes in forage production technologies in the Leningrad region of Russia, analyzed the implications of these changes for production and financial performance of dairy farming, proposed and tested methods for determination of the optimum harvesting time of perennial grasses. Special attention is paid to the long-term effects of changing the structure of cows' diet--shortening the productive use of animals, which reduces the efficiency of dairy herd use and limits the possibility of expanded reproduction. The primary method of the study is the analysis of milk production statistics in the Leningrad region and the Russian Federation. As a result of the study, the necessity to improve the production and investment planning quality, as well as the use of forecasts during planning of dairy production, is grounded.
文摘Monitoring of rangeland forage production at specified spatial and temporal scales is necessary for grazing management and also for implementation of rehabilitation projects in rangelands. This study focused on the capability of a generalized regression neural network(GRNN) model combined with GIS techniques to explore the impact of climate change on rangeland forage production. Specifically, a dataset of 115 monitored records of forage production were collected from 16 rangeland sites during the period 1998–2007 in Isfahan Province, Central Iran. Neural network models were designed using the monitored forage production values and available environmental data(including climate and topography data), and the performance of each network model was assessed using the mean estimation error(MEE), model efficiency factor(MEF), and correlation coefficient(r). The best neural network model was then selected and further applied to predict the forage production of rangelands in the future(in 2030 and 2080) under A1 B climate change scenario using Hadley Centre coupled model. The present and future forage production maps were also produced. Rangeland forage production exhibited strong correlations with environmental factors, such as slope, elevation, aspect and annual temperature. The present forage production in the study area varied from 25.6 to 574.1 kg/hm^2. Under climate change scenario, the annual temperature was predicted to increase and the annual precipitation was predicted to decrease. The prediction maps of forage production in the future indicated that the area with low level of forage production(0–100 kg/hm^2) will increase while the areas with moderate, moderately high and high levels of forage production(≥100 kg/hm^2) will decrease both in 2030 and in 2080, which may be attributable to the increasing annual temperature and decreasing annual precipitation. It was predicted that forage production of rangelands will decrease in the next couple of decades, especially in the western and southern parts of Isfahan Province. These changes are more pronounced in elevations between 2200 and 2900 m. Therefore, rangeland managers have to cope with these changes by holistic management approaches through mitigation and human adaptations.
基金The National Key Research and Development Program(2016YFC0502001)。
文摘Animal husbandry and crop farming are specialized for development in separate areas on the Tibetan Plateau. Such a pattern of isolation has led to current concerns of rangeland and farming system degradation due to intensive land use. The crop-livestock integration, however, has been proven to increase food and feed productivity thorough niche complementarity, and is thereby especially effective for promoting ecosystem resilience. Regional synergy has emerged as an integrated approach to reconcile rangeland livestock with forage crop production. It moves beyond the specialized sectors of animal husbandry and intensive agriculture to coordinate them through regional coupling. Therefore, crop-livestock integration(CLI) has been suggested as one of the effective solutions to forage deficit and livestock production in grazing systems. But it is imperative that CLI moves forward from the farm level to the regional scale, in order to secure regional synergism during agro-pastoral development. The national key R & D program, Technology and Demonstration of Recovery and Restoration of Degraded Alpine Ecosystems on the Tibetan Plateau, aims to solve the problems of alpine grassland degradation by building up a grass-based animal husbandry technology system that includes synergizing forage production and ecological functioning, reconciling the relationship between ecology, forage production and animal husbandry, and achieving the win-win goals of curbing grassland degradation and changing the development mode of animal husbandry. It is imperative to call for regional synergy through integrating ecological functioning with ecosystem services, given the alarming threat of rangeland degradation on the Tibetan Plateau. The series of papers in this issue, together with those published previously, provide a collection of rangeland ecology and management studies in an effort to ensure the sustainable use and management of the alpine ecosystems.
文摘This research was aimed to evaluate the productivity of native pasture in Timor Island by introducing various palatable species.The study was carried out on native pasture in Tuatuka,Timor Island for seven months.The study was performed by using randomized block design(RBD)with eight treatments(S0:no introduction,S1:Cynodon dactilon,S2:Dicanthium aristatum,S3:C.plectotachyus,S4:Brachiaria decumbens,S5:Desmanthus virgatus,S6:Macroptilium atropurpureum,S7:Clitoria ternatea)with four replications.Procedures on this study include trial plots preparation,tillers preparation for each species,introduction of species in trial plots,maintenance and observation of the productivity.Variables observed were forage production(fresh and dry matter(DM)in ton/ha),nutrient content(%)and stock capacity(animal unit(AU)/ha).Data were analyzed for variance based on RBD and followed by Duncan’s test.Analysis of variance showed that introduction of species had a very significant effect(p<0.01)on all observed variables.The introduction of M.atropurpureum produced the highest fresh forage(2.1 t/ha)and DM production(0.69 t/ha).M.atropurpureum also had the highest DM content(43.61%),nitrogen free extract(52.52%)and stock capacity(1.06 AU/ha).The highest crude protein and crude fiber content were found in D.virgatus(4.31%and 36.62%).The highest extract ether was observed in D.aristatum(1.48%).No introduction had the lowest productivity,but demonstrated the highest ash content.The introduction of palatable species increased the productivity of native pasture in Timor and M.atropupureum was the best introduced species.
文摘Determining biomass production of individual alfalfa (Medicago sativa L.) plants in space planted evaluation studies is generally not feasible. Clipping plants is time consuming, expensive, and often not possible if the plants are subjected to grazing. A regression function (B′ = 0.72558 + 0.11638 × V′) was developed from spaced plants growing on rangeland in northwestern South Dakota near Buffalo to nondestructively estimate individual plant biomass (B) from canopy volume (V). However, external validation is necessary to effectively apply the model to other environments. In the summer of 2015, new data to validate the model were collected from spaced plants near Brookings, South Dakota. Canopy volume and clipped plant biomass were obtained from ten alfalfa populations varying in genetic background, growth habit, and growth stage. Fitted models for the model-building and validation data sets had similar estimated regression coefficients and attributes. Mean squared prediction errors (MSPR) were similar to or smaller than error mean square (MSE) of the model-building regression model, indicating reasonable predictive ability. Validation results indicated that the model reliably estimated biomass of plants in another environment. However, the technique should not be utilized where individual plants are not easily distinguished, such as alfalfa monocultures. Estimating biomass from canopy volume values that are extrapolations (>2.077 × 10<sup>6</sup> cm<sup>3</sup>) of the model-building data set is not recommended.
基金FP7 Food,Agriculture and Fisheries,Biotechnology,Grant/Award Number:266018。
文摘Background:More frequent and severe drought events due to climate change pose a major challenge for sustainable forage production in managed grasslands.This study investigated whether multispecies grassland communities can provide greater resistance to and/or recovery from drought compared to monoculture communities.Methods:Mesocosms of Lolium perenne L.,Cichorium intybus L.,Trifolium repens L.and Trifolium pratense L.were established as monocultures,and a four-species mixture.A drought gradient with five levels of water supply ranging from a mild to a severe treatment was applied for 10 weeks,in each of 2 years.Shoot biomass was harvested to assess drought resistance,drought recovery and annual yields.Root mass density and specific root length were measured in Year 2.Results:Across the drought gradient,four-species communities had significantly larger annual yields than each of the four monocultures,indicating transgressive overyielding.This was despite relatively low drought resistance for four-species communities compared with L.perenne and C.intybus monocultures.Recovery of yields following drought was high for all communities.Conclusions:Multispecies swards with complementary traits can provide a viable adaptation option across a wide range of drought severities.Application of a stress gradient methodology allowed a more detailed understanding of stress responses.
基金Funding was provided through the AnimalChange project which received funding from the European Community’s Seventh Framework Programme(grant agreement no.266018).
文摘Aims Research on the effects of extreme rainfall events on ecosystem function has primarily focussed on drought or flooding events,which usually include changes to mean or total rainfall,annually or over a season.However,less is known about the effects of increased rainfall variability without change to mean or total amounts.We investigated the effects of increased variation of water supply on shoot and root biomass as well as the distribution of root biomass of four grassland plant species,grown in monoculture and mixture communities.Methods Perennial ryegrass(Lolium perenne L.,shallow-rooting grass),chicory(Cichorium intybus L.,deep-rooting forb),white clover(Trifolium repens L.,shallow-rooting legume)and red clover(Trifolium pratense L.,deep-rooting legume)were established in mesocosms.Four plants of the same species were grown in monoculture communities and one of each species grown in four-species communities.Water supply was manipulated such that;compared with a baseline level with low variation in water supply,there was a treatment with medium variation(±40%)and another with high variation(±80%).Shoot and root biomass were measured,and vertical root distribution models fitted.Important Findings Compared with the low variation treatment,shoot biomass was significantly reduced under high variation for white clover,red clover and four-species communities.Under all conditions,four-species communities produced more shoot and root biomass than predicted by species performance in monoculture(overyielding).Under increased water variation,chicory monocultures allocated a higher proportion of root biomass to deeper soil layers while the total root biomass of white clover monocultures was significantly reduced.These results indicate that increased variability of water supply can negatively affect the shoot and root biomass production of single and multi-species grasslands.There is a need for further investigation of water variation effects on the functioning of multi-species grassland systems at field scale.
基金The National Key Research and Development Program of China(2016YFC0502001,2016YFC0501803)Kailash Sacred Landscape Conservation and Development Initiative from ICIMOD
文摘Crop-livestock integration(CLI)is a significant practice for livestock grazing systems in alpine rangelands.It offers the potential to achieve sustainable crop and livestock production.However,the separate crop and livestock systems that exist today have led to issues of intensive agriculture,rangeland degradation and forage shortage in the Tibetan Plateau.Developing crop-livestock integration through sown pastures can be an effective way to lift pasture productivity and improve livestock production.Thus,to explore the potential for integrating crop and livestock production in alpine grazing systems,an assessment of potential forage and livestock production using multiple datasets was carried out in Burang County,China.Results showed the marginal land potentially available for sown pastures was about 560 ha,located mostly in the Burang township of the Karnali basin.Accumulated temperature was the dominant limiting factor for establishing sown pastures,therefore cold tolerance of forage species and growth period should be taken into consideration.Furthermore,the number of livestock decreased during the period 2012–2016;yet often,the number of livestock in rangeland landscape was greater than that in agro-pastoral landscape.The average number of livestock was about 110000 standard sheep units(SU)in the study area,but forage from sown pastures and crop residues could potentially feed about 11000 SU,accounting for 50%of the livestock population in the Karnali basin.We found that integrating crop and forage production could fill feed gaps for grazing systems,particularly in the agro-pastoral landscape of the Karnali basin.The results of this study provide scientific support to guide future forage production and to promote further crop and livestock integration in Burang County.