Theme 1-2: Rangeland/Grassland Ecology--Poster Sessions

Description

Herbaceous vegetation in grassland ecosystems is characterised by grass dominance in a species-rich forb-grass mixture. Forbs (i.e. the non-graminoid herbaceous component) represent the largest proportion of total species- and functional richness, which secure important ecosystem functions. Although grasses remain the most important forage source, certain forb species provide nutritious food sources for herbivores. Moreover, forbs provide food- and habitat sources to enhance invertebrate diversity and hence, agricultural food security through the maintenance of healthy pollinator communities. Important food and medicinal sources for human livelihoods in developing countries are also largely contributed by forbs. However, the dynamics and ecology of forb species are poorly understood in rangeland systems. Increasing global pressures are threatening the hyper-diverse grassland ecosystems (including African savannas) and in particular the diversity of the forb flora. The sub-ordinate role of forbs in savanna and grassland rangeland management practices led us to accumulate evidence of important ecosystem functions and services provided by this diverse life form. In this study, we present results that were obtained from several independent studies in which forb data were collected and analysed as an equally important herbaceous life form, to contribute to our current understanding of the ecology of grassland ecosystems. Our results revealed evidence of forbs as important forage for large African mammalian herbivores, including domestic cattle, during periods when other forage resources are severely limited. However, sustained overgrazing can severely deplete forb populations and diversity. Forbs as grazing indicators have been identified as the basis of a proposed forb-condition scoring method for mesic grasslands. Furthermore, the importance of intermediate disturbances, such as moderate grazing and/or the maintenance of crop field margins were identified for invertebrate community conservation. Studies on useful indigenous plants exposed forbs as an important life form to provide food- and medicinal resources to human livelihoods in African grassland ecosystems.

Share

COinS
 

The Functional Importance of Forbs in Grassland Ecosystems

Herbaceous vegetation in grassland ecosystems is characterised by grass dominance in a species-rich forb-grass mixture. Forbs (i.e. the non-graminoid herbaceous component) represent the largest proportion of total species- and functional richness, which secure important ecosystem functions. Although grasses remain the most important forage source, certain forb species provide nutritious food sources for herbivores. Moreover, forbs provide food- and habitat sources to enhance invertebrate diversity and hence, agricultural food security through the maintenance of healthy pollinator communities. Important food and medicinal sources for human livelihoods in developing countries are also largely contributed by forbs. However, the dynamics and ecology of forb species are poorly understood in rangeland systems. Increasing global pressures are threatening the hyper-diverse grassland ecosystems (including African savannas) and in particular the diversity of the forb flora. The sub-ordinate role of forbs in savanna and grassland rangeland management practices led us to accumulate evidence of important ecosystem functions and services provided by this diverse life form. In this study, we present results that were obtained from several independent studies in which forb data were collected and analysed as an equally important herbaceous life form, to contribute to our current understanding of the ecology of grassland ecosystems. Our results revealed evidence of forbs as important forage for large African mammalian herbivores, including domestic cattle, during periods when other forage resources are severely limited. However, sustained overgrazing can severely deplete forb populations and diversity. Forbs as grazing indicators have been identified as the basis of a proposed forb-condition scoring method for mesic grasslands. Furthermore, the importance of intermediate disturbances, such as moderate grazing and/or the maintenance of crop field margins were identified for invertebrate community conservation. Studies on useful indigenous plants exposed forbs as an important life form to provide food- and medicinal resources to human livelihoods in African grassland ecosystems.