A recently held SEED Symposium in Pretoria, South Africa celebrated outstanding grassroots, social and environmental businesses in Africa and other regions.
The revolution that ended the rule of the autocratic monarchy in China 100 years ago continues to inspire people to rejuvenate the nation The 1911 Revolution,also known as the Xinhai Revolution, is an important milest...The revolution that ended the rule of the autocratic monarchy in China 100 years ago continues to inspire people to rejuvenate the nation The 1911 Revolution,also known as the Xinhai Revolution, is an important milestone in China’s history.展开更多
Aims Species aggregation is commonly seen in plant communities and may increase diversity by causing intraspecific competition to exceed interspecific competition.One potential source of this spatial aggregation is se...Aims Species aggregation is commonly seen in plant communities and may increase diversity by causing intraspecific competition to exceed interspecific competition.One potential source of this spatial aggregation is seed dispersal but it is unclear to what extent aggregated seed distributions affect plant diversity in real communities.Using a field experiment,I tested whether uniform or aggregated seed arrival alters community structure and whether these effects vary with sowing density.Methods The experiment consisted of two spatial seeding treatments(uniform and aggregated)that were fully crossed with three seed density treatments.Sixty,3×4-m plots were arrayed in a low-diversity grassland located in Kansas,USA.Each plot was divided into fortyeight,0.5×0.5-m patches.For aggregated seeding treatments,each of the 15 species was sown into three randomly selected patches within the plot(3×15=45).To create a uniform species arrival but control for the seed addition method,all 15 species were sown into 45 individual patches(with three patches remaining unsown)within each plot.Seed mass for each species was held constant at the plot scale between uniform or aggregated treatments within a given level of the sowing density treatment.After two growing seasons,plant density was quantified for all sown species in 15 randomly selected patches from each plot.Important Findings I found evidence for shifts in community structure in response to the different spatial seeding patterns.The evenness of added species was higher under aggregated than uniform sowing patterns.There was no detectable effect of aggregated seed sowing on species richness at 3.75 m^(2) scale.However,when species richness was extrapolated to larger scales(11.25 m^(2)),aggregated sowing was predicted to have greater richness than uniform sowing.Effects of seed aggregation on community structure were apparent only at moderate to high sowing rates,yet the latter are within the range of measured seed dispersal in similar grasslands.Additionally,as sowing density increased,seed mass became an increasingly effective predictor of relative abundances for added species,but only under uniform sowing patterns supporting the idea that aggregated dispersal may buffer weaker(smaller seeded)species from competition during colonization.This is the first experiment to show that aggregated seed dispersal patterns can increase at least some components of plant diversity in undisturbed grasslands and suggests that previous seed dispersal experiments,which utilize uniform seed sowing,may underestimate the potential effect of dispersal on plant community structure.展开更多
In Central-and Eastern Europe,the collapse of socialist regimes resulted in a transformation of state-owned agricultural cooperatives to privately owned lands from the early 1990s onwards.These socioeconomic processes...In Central-and Eastern Europe,the collapse of socialist regimes resulted in a transformation of state-owned agricultural cooperatives to privately owned lands from the early 1990s onwards.These socioeconomic processes resulted in landscape-scale changes in biodiversity,ecosystem services and agricultural production.In parallel,large-scale abandonment of croplands,especially on sandy,salty or fre-quently inundated areas,became common.Abandoned croplands are usually sensitive to species invasions,and are hotspots of noxious weeds,posing threats both to agriculture and nature conservation.Grassland restoration on former croplands can be an effective strategy for suppressing these species.Thus,a common goal of nature conservation and agriculture can be the restoration of grasslands on former croplands to(1)suppress weed and/or invasive species in line with the EU policy“Good Farming Practices”,(2)support animal husbandry by creating meadows or pastures,and to(3)recover biodiversity and ecosystem services.In the present paper we report“best practices”of grassland restoration projects from Hungary.Our aim was to compare the effectiveness of spontaneous grassland recovery vs.active grassland restoration by seed sowing in terms of the recovery of biodiversity and ecosystem services,such as weed control and biomass production.Our results showed that grassland restoration on abandoned fields offers a viable solution for restoring biodiversity and ecosystem services.Seed sowing ensures higher weed control and biomass pro-duction,but results in lower biodiversity compared to spontaneous recovery.Both restoration methods can be cost-effective,or even profitable even within a relatively short period of a nature conservation project.展开更多
文摘A recently held SEED Symposium in Pretoria, South Africa celebrated outstanding grassroots, social and environmental businesses in Africa and other regions.
文摘The revolution that ended the rule of the autocratic monarchy in China 100 years ago continues to inspire people to rejuvenate the nation The 1911 Revolution,also known as the Xinhai Revolution, is an important milestone in China’s history.
基金Wichita State UniversityNational Science Foundation(EPS 0903806).
文摘Aims Species aggregation is commonly seen in plant communities and may increase diversity by causing intraspecific competition to exceed interspecific competition.One potential source of this spatial aggregation is seed dispersal but it is unclear to what extent aggregated seed distributions affect plant diversity in real communities.Using a field experiment,I tested whether uniform or aggregated seed arrival alters community structure and whether these effects vary with sowing density.Methods The experiment consisted of two spatial seeding treatments(uniform and aggregated)that were fully crossed with three seed density treatments.Sixty,3×4-m plots were arrayed in a low-diversity grassland located in Kansas,USA.Each plot was divided into fortyeight,0.5×0.5-m patches.For aggregated seeding treatments,each of the 15 species was sown into three randomly selected patches within the plot(3×15=45).To create a uniform species arrival but control for the seed addition method,all 15 species were sown into 45 individual patches(with three patches remaining unsown)within each plot.Seed mass for each species was held constant at the plot scale between uniform or aggregated treatments within a given level of the sowing density treatment.After two growing seasons,plant density was quantified for all sown species in 15 randomly selected patches from each plot.Important Findings I found evidence for shifts in community structure in response to the different spatial seeding patterns.The evenness of added species was higher under aggregated than uniform sowing patterns.There was no detectable effect of aggregated seed sowing on species richness at 3.75 m^(2) scale.However,when species richness was extrapolated to larger scales(11.25 m^(2)),aggregated sowing was predicted to have greater richness than uniform sowing.Effects of seed aggregation on community structure were apparent only at moderate to high sowing rates,yet the latter are within the range of measured seed dispersal in similar grasslands.Additionally,as sowing density increased,seed mass became an increasingly effective predictor of relative abundances for added species,but only under uniform sowing patterns supporting the idea that aggregated dispersal may buffer weaker(smaller seeded)species from competition during colonization.This is the first experiment to show that aggregated seed dispersal patterns can increase at least some components of plant diversity in undisturbed grasslands and suggests that previous seed dispersal experiments,which utilize uniform seed sowing,may underestimate the potential effect of dispersal on plant community structure.
基金The pub-lication was supported by the SROP-4.2.2.B-15/1/KONV-2015-0001 projectThe project has been supported by the European Union,co-financed by the European Social Fund.The research was also supported by OTKA PD 111807 and OTKA K 116639.
文摘In Central-and Eastern Europe,the collapse of socialist regimes resulted in a transformation of state-owned agricultural cooperatives to privately owned lands from the early 1990s onwards.These socioeconomic processes resulted in landscape-scale changes in biodiversity,ecosystem services and agricultural production.In parallel,large-scale abandonment of croplands,especially on sandy,salty or fre-quently inundated areas,became common.Abandoned croplands are usually sensitive to species invasions,and are hotspots of noxious weeds,posing threats both to agriculture and nature conservation.Grassland restoration on former croplands can be an effective strategy for suppressing these species.Thus,a common goal of nature conservation and agriculture can be the restoration of grasslands on former croplands to(1)suppress weed and/or invasive species in line with the EU policy“Good Farming Practices”,(2)support animal husbandry by creating meadows or pastures,and to(3)recover biodiversity and ecosystem services.In the present paper we report“best practices”of grassland restoration projects from Hungary.Our aim was to compare the effectiveness of spontaneous grassland recovery vs.active grassland restoration by seed sowing in terms of the recovery of biodiversity and ecosystem services,such as weed control and biomass production.Our results showed that grassland restoration on abandoned fields offers a viable solution for restoring biodiversity and ecosystem services.Seed sowing ensures higher weed control and biomass pro-duction,but results in lower biodiversity compared to spontaneous recovery.Both restoration methods can be cost-effective,or even profitable even within a relatively short period of a nature conservation project.
