Over the last decades, the reduction of manpower for herd management has led to an increase of continuous grazing systems(CGS) in the Italian Alps, which allow cattle to roam freely. Under CGS, due to high selectivity...Over the last decades, the reduction of manpower for herd management has led to an increase of continuous grazing systems(CGS) in the Italian Alps, which allow cattle to roam freely. Under CGS, due to high selectivity, livestock exploit grasslands unevenly, over-and under-using specific areas at the same time with negative effects on their conservation. To counteract these effects, a specific policy and management tool(i.e. Grazing Management Plan) has been implemented by Piedmont Region since 2010. The Grazing Management Plans are based on the implementation of rotational grazing systems(RGS), with animal stocking rate adjusted to balance it with grassland carrying capacity. A case study was conducted on alpine summer pastures to test the 5-year effects produced by the implementation of a Grazing Management Plan in grasslands formerly managed under several years of CGS on 1) the selection for different vegetation communities by cattle, 2) the abundance of oligo-, meso-, and eutrophic plant species(defined according to Landolt N indicator value), and 3) forage yield, quality, and palatability. A total of 193 vegetation surveys were carried out in 2011 and repeated in 2016. Cows were tracked yearly with Global Positioning System collars to assess their grazing selectivity, and forage Pastoral Value(PV) was computed to evaluate forage yield, quality, and palatability. Five years after RGS implementation, cow selectivity significantly decreased and the preference for the different vegetation communities was more balanced than under CGS. The abundance of meso-and eutrophic species increased, whereas oligotrophic ones decreased. Moreover, the abundance of moderately to highly palatable plant species increased, whereas non-palatable plant species decreased, with a consequent significant enhancement of the PV. Our findings indicate that the implementation of Grazing Management Plans can be considered a sustainable and effective management tool for improving pasture selection by cattle and forage quality in mountain pastures.展开更多
The study of plant phenology has frequently been used to link phenological events to various factors,such as temperature or photoperiod.In the high-alpine environment,proper timing of the phenological cycle has always...The study of plant phenology has frequently been used to link phenological events to various factors,such as temperature or photoperiod.In the high-alpine environment,proper timing of the phenological cycle has always been crucial to overcome harsh conditions and potential extreme events(i.e.spring frosts)but little is known about the response dynamics of the vegetation,which could shape the alpine landscape in a future of changing climate.Alpine tundra vegetation is composed by an array of species belonging to different phytosociological optima and with various survival strategies,and snowbed communities are a relevant expression of such an extreme-climate adapted flora.We set eight permanent plots with each one in a snowbed located on the Cimalegna plateau in Northwestern Italy and then we selected 10 most recurring species among our plots,all typical of the alpine tundra environment and classified in 3different pools:snowbed specialists,grassland species and rocky debris species.For 3 years we registered the phenophases of each species during the whole growing season using an adaptation of the BBCH scale.We later focused on the three most biologically relevant phenophases,i.e.,flower buds visible,full flowering,and beginning of seed dispersion.Three important season-related variables were chosen to investigate their relationship with the phenological cycle of the studied species:(i)the Day Of Year(DOY),the progressive number of days starting from the 1 st of January,used as a proxy of photoperiod,(ii)Days From Snow Melt(DFSM),selected to include the relevance of the snow dynamics,and(iii)Growing Degree Days(GDD),computed as a thermal sum.Our analysis highlighted that phenological development correlated better with DFSM and GDD than with DOY.Indeed,models showed that DOY was always a worse predictor since it failed to overcome interannual variations,while DFSM and marginally GDD were better suited to predict the phenological development of most of the species,despite differences intemperature and snowmelt date among the three years.Even if the response pattern to the three variables was mainly consistent for all the species,the timing of their phenological response was different.Indeed,species such as Salix herbacea and Ranunculus glacialis were always earlier in the achievement of the phenophases,while Agrostis rupestris and Euphrasia minima developed later and the remaining species showed an intermediate behavior.However,we did not detect significant differences among the three functional pools of species.展开更多
文摘Over the last decades, the reduction of manpower for herd management has led to an increase of continuous grazing systems(CGS) in the Italian Alps, which allow cattle to roam freely. Under CGS, due to high selectivity, livestock exploit grasslands unevenly, over-and under-using specific areas at the same time with negative effects on their conservation. To counteract these effects, a specific policy and management tool(i.e. Grazing Management Plan) has been implemented by Piedmont Region since 2010. The Grazing Management Plans are based on the implementation of rotational grazing systems(RGS), with animal stocking rate adjusted to balance it with grassland carrying capacity. A case study was conducted on alpine summer pastures to test the 5-year effects produced by the implementation of a Grazing Management Plan in grasslands formerly managed under several years of CGS on 1) the selection for different vegetation communities by cattle, 2) the abundance of oligo-, meso-, and eutrophic plant species(defined according to Landolt N indicator value), and 3) forage yield, quality, and palatability. A total of 193 vegetation surveys were carried out in 2011 and repeated in 2016. Cows were tracked yearly with Global Positioning System collars to assess their grazing selectivity, and forage Pastoral Value(PV) was computed to evaluate forage yield, quality, and palatability. Five years after RGS implementation, cow selectivity significantly decreased and the preference for the different vegetation communities was more balanced than under CGS. The abundance of meso-and eutrophic species increased, whereas oligotrophic ones decreased. Moreover, the abundance of moderately to highly palatable plant species increased, whereas non-palatable plant species decreased, with a consequent significant enhancement of the PV. Our findings indicate that the implementation of Grazing Management Plans can be considered a sustainable and effective management tool for improving pasture selection by cattle and forage quality in mountain pastures.
文摘The study of plant phenology has frequently been used to link phenological events to various factors,such as temperature or photoperiod.In the high-alpine environment,proper timing of the phenological cycle has always been crucial to overcome harsh conditions and potential extreme events(i.e.spring frosts)but little is known about the response dynamics of the vegetation,which could shape the alpine landscape in a future of changing climate.Alpine tundra vegetation is composed by an array of species belonging to different phytosociological optima and with various survival strategies,and snowbed communities are a relevant expression of such an extreme-climate adapted flora.We set eight permanent plots with each one in a snowbed located on the Cimalegna plateau in Northwestern Italy and then we selected 10 most recurring species among our plots,all typical of the alpine tundra environment and classified in 3different pools:snowbed specialists,grassland species and rocky debris species.For 3 years we registered the phenophases of each species during the whole growing season using an adaptation of the BBCH scale.We later focused on the three most biologically relevant phenophases,i.e.,flower buds visible,full flowering,and beginning of seed dispersion.Three important season-related variables were chosen to investigate their relationship with the phenological cycle of the studied species:(i)the Day Of Year(DOY),the progressive number of days starting from the 1 st of January,used as a proxy of photoperiod,(ii)Days From Snow Melt(DFSM),selected to include the relevance of the snow dynamics,and(iii)Growing Degree Days(GDD),computed as a thermal sum.Our analysis highlighted that phenological development correlated better with DFSM and GDD than with DOY.Indeed,models showed that DOY was always a worse predictor since it failed to overcome interannual variations,while DFSM and marginally GDD were better suited to predict the phenological development of most of the species,despite differences intemperature and snowmelt date among the three years.Even if the response pattern to the three variables was mainly consistent for all the species,the timing of their phenological response was different.Indeed,species such as Salix herbacea and Ranunculus glacialis were always earlier in the achievement of the phenophases,while Agrostis rupestris and Euphrasia minima developed later and the remaining species showed an intermediate behavior.However,we did not detect significant differences among the three functional pools of species.
基金This study was supported by the National Key Research and Development Program of China(2016YFC0500503 and 2016YFC0500501)by the Department of Science and Technology of Inner Mongolia Autonomous Region for studying steppe ecosystems on the Mongolian Plateau(20140409 and 201503001).