IPBES Invasive Alien Species Assessment: Summary for Policymakers

Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services

Performance of invasive alien fountain grass (Pennisetum setaceum) along a climatic gradient through three South African biomes

CITATION: Rahlao, S. J., et al. 2019. Performance of invasive alien fountain grass (Pennisetum setaceum) along a climatic gradient through three South African biomes. South African Journal of Botany, 91:43-48, doi:10.1016/j.sajb.2013.11.013.The original publication is available https://www.sciencedirect.com/The knowledge of relative performance of plants across environmental gradients is critical for their effective management and for understanding future range expansion. Pennisetum setaceum is an invasive perennial grass found along roadsides and other disturbed sites in South Africa. The performance of this grass in response to competition, habitat characteristics and resources was experimentally tested in three biomes (Karoo, Fynbos and Savanna) of South Africa. A total of 846 young P. setaceum seedlings were translocated to study sites in May 2007. The seedlings were grown in 94 plots along random transects, of which alternate halves were cleared of vegetation. Despite a variety of environmental hazards at these sites, over 30% of the transplanted seedlings survived over 15 months. Competition from resident vegetation was a major factor limiting the establishment of seedlings. However, under adequate rainfall and historical disturbance (mine dump), competition effects were overridden. Survival of seedlings was greatest in the Karoo National Park, possibly because of summer rainfall that occurred shortly after translocation. Despite differences in the survival and growth rates, seedlings remained alive at all sites, especially if they survived the first six months after translocation. P. setaceum is capable of persisting across a broad range of environmental conditions. Management efforts should aim to reduce seed production and establishment along roadsides that act as conduits into protected sites. This could be best achieved by maintaining as much indigenous cover along road verges as possible, as seeds survive best where competition is low.https://www.sciencedirect.com/science/article/pii/S0254629913004663Publishers' Versio

Vegetation dynamics after experimental fire disturbance in the arid Succulent Karoo, South Africa

<p>Disturbance by fire in the Succulent Karoo is rare but fire events could increase as a result of an increase in grassiness (alien and indigenous species). This study assessed the effects of fire eight years after an experimentally induced burn in Succulent Karoo vegetation. Post-fire monitoring was conducted using the line intercept method and species counts per plot (1 m²) for each of three fire disturbance treatments: control/unburnt, high and low fuel load. Vegetation cover and abundance were compared across treatments and growth forms. Vegetation cover and abundance on fire-disturbed plots had not returned to pre-fire levels after eight years. Resprouters exhibited a rapid recovery and early dominance on burnt plots. Succulent seedlings established slower, but after eight years occurred at higher densities on the burnt than control plots. Recovery after disturbance of density and cover of long-lived, woody non-resprouter non-succulents was slow relative to resprouting non-succulents and reseeding succulents. This study of vegetation change following fire disturbance in an arid system highlights the slow return of canopy cover, immediate regrowth of only two resprouter species and slower re-establishment by seed of non-resprouter species. In addition, fire disturbance led to the numerical dominance of succulents within the first decade after the fire.</p

IPBES Invasive Alien Species Assessment: Summary for Policymakers

&lt;p&gt;Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services&lt;/p&gt;Suggested citation: IPBES (2023). Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Roy, H. E., Pauchard, A., Stoett, P., Renard Truong, T., Bacher, S., Galil, B. S., Hulme, P. E., Ikeda, T., Sankaran, K. V., McGeoch, M. A., Meyerson, L. A., Nuñez, M. A., Ordonez, A., Rahlao, S. J., Schwindt, E., Seebens, H., Sheppard, A. W., and Vandvik, V. (eds.). IPBES secretariat, Bonn, Germany. https://doi.org/10.5281/zenodo.743069

IPBES Invasive Alien Species Assessment: Summary for Policymakers. Figures, tables and captions

&lt;p&gt;Figures, tables and their captions from the&nbsp;Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.&lt;/p&gt

IPBES Invasive Alien Species Assessment: Summary for Policymakers. Figures, tables and captions

&lt;p&gt;Figures, tables and their captions from the&nbsp;Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.&lt;/p&gt

Key knowledge gaps to achieve global sustainability goals

Regional and global assessments periodically update what we know, and highlight what remains to be known, about the linkages between people and nature that both define and depend upon the state of the environment. To guide research that better informs policy and practice, we systematically synthesize knowledge gaps from recent assessments of four regions of the globe and three key themes by the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services. We assess their relevance to global sustainability goals and trace their evolution relative to those identified in the Millennium Ecosystem Assessment. We found that global sustainability goals cannot be achieved without improved knowledge on feedbacks between social and ecological systems, effectiveness of governance systems and the influence of institutions on the social distribution of ecosystem services. These top research priorities have persisted for the 14 years since the Millennium Ecosystem Assessment. Our analysis also reveals limited understanding of the role of indigenous and local knowledge in sustaining nature’s benefits to people. Our findings contribute to a policy-relevant and solution-oriented agenda for global, long-term social-ecological research.</p