Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this industry.Around 20%of global grasslands are highly degraded due to overgrazing,...Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this industry.Around 20%of global grasslands are highly degraded due to overgrazing,affecting their productivity and conservation capacity.Best practices are required to ensure sustainable livestock production that supports biodiversity.The Intermediate Disturbance Hypothesis(IDH)suggests that environments with moderate levels of disturbance exhibit a higher species diversity.Moderate grazing can reduce the dominance of certain species,thereby enhancing plant diversity.However,concerns arise regarding the increase of exotic and unpalatable species under moderate grazing levels,complicating grassland conservation efforts.The impact of livestock grazing on the functional structure of grasslands depends on factors such as grazing intensity,livestock species,and environmental conditions.Variations in grazing intensity may increase specific and functional diversity under moderate grazing,potentially masking the presence of invasive exotic species.In the Austral Pampas(Pampean phytogeographic province,Buenos Aires,Argentina),grasslands face various pressures from domestic livestock grazing that endanger their integrity if not properly managed.Therefore,our study aims to investigate potential differences in species richness and diversity,functional diversity,exotic plant abundance,and the number and distribution of plant functional groups across varying grazing intensities.The IDH is utilized as a tool to regulate livestock pressure for grassland conservation.Species and functional diversity indices were used to assess the impact of grazing on grassland diversity.Moderate grazing increased species and functional diversity,while intensively grazed or ungrazed areas showed reduced diversity.Livestock presence influenced the balance between native and exotic plants,with ungrazed areas having higher native plant abundance and grazed areas exhibiting higher exotic plant abundance.Grazing also influenced the composition of functional groups,with grazing-avoiding species being more prevalent in heavily grazed areas.Principal Component Analysis revealed a clear association between vegetation composition and livestock grazing intensity.These findings offer valuable insights into effectively managing grazing intensity for biodiversity conservation purposes.展开更多
The study aimed at understanding the current avifauna characteristics, like composition, species diversity and evolution, in the city of Kinshasa. The study was conducted from 2006 to 2014, using observation, photogra...The study aimed at understanding the current avifauna characteristics, like composition, species diversity and evolution, in the city of Kinshasa. The study was conducted from 2006 to 2014, using observation, photography and Japanese nets. Results of the study indicate that there are 131 species of birds, which represents 40 families and 16 orders. Avifauna of Kinshasa represents 11% of species of the all country. Among those species, 12 are new. Passerines are the most, representing 86 species and 21 families, and are the most diversified. Few species have extended their geographical distribution and some are migratory. Overtime, avian fauna of Kinshasa region has undergone a lot of changes in its composition and diversity. Horizontal extension of the city associated with the consecutive various changes of the habitats seems to be the principal factors which modulate those characteristics. However, the study found that the majority of these species were under precarious statute of conservation.展开更多
基金funded by CONICET(Consejo Nacional de Investigaciones Científicas y Técnicas)and SGCyT(Secretaría General de Ciencia y Tecnología,Universidad Nacional del Sur,Argentina).
文摘Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this industry.Around 20%of global grasslands are highly degraded due to overgrazing,affecting their productivity and conservation capacity.Best practices are required to ensure sustainable livestock production that supports biodiversity.The Intermediate Disturbance Hypothesis(IDH)suggests that environments with moderate levels of disturbance exhibit a higher species diversity.Moderate grazing can reduce the dominance of certain species,thereby enhancing plant diversity.However,concerns arise regarding the increase of exotic and unpalatable species under moderate grazing levels,complicating grassland conservation efforts.The impact of livestock grazing on the functional structure of grasslands depends on factors such as grazing intensity,livestock species,and environmental conditions.Variations in grazing intensity may increase specific and functional diversity under moderate grazing,potentially masking the presence of invasive exotic species.In the Austral Pampas(Pampean phytogeographic province,Buenos Aires,Argentina),grasslands face various pressures from domestic livestock grazing that endanger their integrity if not properly managed.Therefore,our study aims to investigate potential differences in species richness and diversity,functional diversity,exotic plant abundance,and the number and distribution of plant functional groups across varying grazing intensities.The IDH is utilized as a tool to regulate livestock pressure for grassland conservation.Species and functional diversity indices were used to assess the impact of grazing on grassland diversity.Moderate grazing increased species and functional diversity,while intensively grazed or ungrazed areas showed reduced diversity.Livestock presence influenced the balance between native and exotic plants,with ungrazed areas having higher native plant abundance and grazed areas exhibiting higher exotic plant abundance.Grazing also influenced the composition of functional groups,with grazing-avoiding species being more prevalent in heavily grazed areas.Principal Component Analysis revealed a clear association between vegetation composition and livestock grazing intensity.These findings offer valuable insights into effectively managing grazing intensity for biodiversity conservation purposes.
文摘The study aimed at understanding the current avifauna characteristics, like composition, species diversity and evolution, in the city of Kinshasa. The study was conducted from 2006 to 2014, using observation, photography and Japanese nets. Results of the study indicate that there are 131 species of birds, which represents 40 families and 16 orders. Avifauna of Kinshasa represents 11% of species of the all country. Among those species, 12 are new. Passerines are the most, representing 86 species and 21 families, and are the most diversified. Few species have extended their geographical distribution and some are migratory. Overtime, avian fauna of Kinshasa region has undergone a lot of changes in its composition and diversity. Horizontal extension of the city associated with the consecutive various changes of the habitats seems to be the principal factors which modulate those characteristics. However, the study found that the majority of these species were under precarious statute of conservation.
