Plant species diversity, ecosystem function, and pasture Management—A perspective

Abstract

2007. Plant species diversity, ecosystem function, and pasture management-A perspective. Can. J. Plant Sci. 87: 479-487. Grassland farmers face many challenges in pasture management including improving sustainability, reducing inputs of fertilizers and pesticides, and protecting soil resources. In this paper we provide our perspective on managing plant diversity within and among pastures as one tool to aid producers in meeting these challenges. Pasture ecosystems can be highly diverse, with a complex array of organisms contributing to ecosystem functioning. Within the broad range of plant and animal biodiversity in pastures, plant species diversity may be the most amenable to manipulation or management. Reported benefits of plant diversity in grasslands include: increased forage production, greater ecosystem stability in response to disturbance, and reduced invasion by exotic species such as weeds. Some view diversity as a sort of insurance policy where different species contribute in their own time or can take the place of species that fail from stress or mismanagement. Using mixtures of several forages in pastures, in some instances, can improve forage yield and reduce weed invasions. Pasture management for increased plant species diversity, however, is not simply mixing and planting as many forage species as possible. The kinds and amounts of different forage species along with their arrangement within and among pastures at the farm scale are critical features that must be considered. Tools must be developed to determine the appropriate species mixtures for varying soils, landscapes, climate and purposes to fulfill multiple functions for producers.. et Deak, A. 2007. Diversité des espèces végétales, fonction de l'écosystème et gestion des pâturages-un point de vue. Can. J. Plant Sci. 87: 479-487. Pour les agriculteurs des prairies, la gestion des pâturages pose maintes difficultés parmi lesquelles comment rendre ces derniers plus durables, comment réduire l'usage des engrais et des pesticides, et comment préserver les ressources du sol. Dans cet article, les auteurs donnent leur point de vue sur la gestion de la diversité des espèces végétales dans le pâturage et entre les pâturages en tant qu'outil susceptible d'aider les producteurs à surmonter ces difficultés. L'écosystème des pâturages varie considérablement, un ensemble complexe d'organismes concourant à son fonctionnement. Parmi la grande variété de plantes et d'animaux qui peuplent un pâturage, c'est la diversité des espèces végétales qu'on pourrait sans doute le mieux modifier et gérer. Parmi les avantages de la diversité végétale dans les prairies, mentionnons une plus grande production fourragère, une meilleure stabilité de l'écosystème advenant une perturbation et une résistance accrue à l'envahissement par des espèces exotiques telles les adventices. Certains voient dans la diver-sité une police d'assurance, les différentes espèces contribuant à l'ensemble le moment venu ou se substituant aux espèces qui cèdent au stress ou aux erreurs de gestion....

Review: Redesigning Canadian prairie cropping systems for profitability, sustainability, and resilience

“…Overyielding in these studies was attributed to N fixation by legumes, niche complementarity, and resource use efficiency in mixtures. Sanderson et al (2007) also suggest that diversity in perennial forage stands provides yield stability where stresses such as drought occur and where there is variability in soils, landscape, and climate. As such, perennial polyculture adds a degree of resilience to agricultural systems.…”

Biodiversity for multifunctional grasslands: equal productivity in high-diversity low-input and low-diversity high-input systems

“…Multifunctional grassland management seeks to provide a large number of ecosystem services (Sanderson et al, 2007;Lemaire et al, 2005), including ecological processes that have been shown to be more effective with increasing species diversity (Balvanera et al, 2006;Cardinale et al, 2006;Diaz et al, 2006;Hector and Bagchi, 2007). At present, multifunctionality is primarily achieved at the landscape or farm level, with high-intensity plots managed for productivity, and low-intensity plots managed for conservation of biodiversity and ecosystem services on more marginal sites.…”

“…Current and future management goals recognise the benefits of multifunctionality in grassland agriculture providing a large number of ecosystem services (Sanderson et al, 2007;Lemaire et al, 2005). These services include ecosystem processes with direct functional benefits in an agricultural context such as yield, decomposition, nutrient leaching, pollination, soil conservation and resistance to weed invasion along with forage stability under changing climatic conditions.…”

Solar Radiation Utilization by Tropical Forage Grasses: Light Interception and Use Efficiency

“…Also, other additional ecosystem functions as enhancement of carbon sequestration or mitigation of greenhouse gas emissions should be considered by farmers as a way of capitalizing new opportunities to diversify the forage-livestock system (Lemaire, 2007, Sanderson et al, 2007. However returning to the first page of this chapter we remember that degradation processes in tropical grassland are advancing over wide areas through overgrazing on poor soils.…”