Decline of plant pollinators threatens biodiversity
Stellenbosch, Konstanz, Leipzig. Approximately 175,000 plant species – half of all flowering plants – mostly or completely rely on animal pollinators to produce and reproduce seeds. This is the result of a recent study published in the journal Science Advances on 13 October 2021 by a global research network with the participation of the German Centre for Integrative Biodiversity Research (iDiv) and the University of Konstanz. A reduction in pollen maters can cause significant disruption to natural ecosystems, including the loss of biodiversity
First global estimate of the importance of pollen maters for plant seed production
Joint media release with University of Konstanz, based on a media release of Stellenbosch University, South Africa.
“Our study is the first to provide a global assessment of the importance of animal pollinators for plants in natural ecosystems,” says Dr James Rodger, lead author of the paper and postdoctoral researcher in the Department of Mathematical Sciences at Stellenbosch University (SU). The study enrolled 21 scientists from 23 institutions on five continents and was led by Dr James Roger and Professor Alan Ellis of the University of Stellenbosch (SU). This is a product of the Center for Biodiversity Science and Synthesis (sDiv) at the Center for Integrated Biodiversity Research (iDiv) in Germany.
Professor Tiffany Knight of the Helmholtz Environmental Research Center (UFZ) and senior co-authors say that recent global pollination assessments have highlighted a gap in knowledge about how plants depend on animal pollinators. increase. “It connects us to link pollen maters’ biodiversity and abundance trends to their impact on plants at the world level,” she says. Knight heads the Spatial Interaction Ecology research group at Martin Luther University Halle-Wittenberg (MLU), the Helmholtz Centre for Environmental Research (UFZ) and iDiv.
Most plants are animal pollinated, but most plants also have some self-pollination. This means that at least some seeds can be produced without pollinators, for example by self-pollination. However, until this study, the question was, “How important are pollen maters to wild plants?” There was no clear answer at the global level.
Researchers have measured seed production in the absence of pollen maters and seed production in the presence of pollen maters as an indicator of their importance to plants. Data on this existed, but spread to hundreds of treatises, each focusing on pollination experiments of different plant species.
To address this issue, researchers from various institutions have begun to integrate information into databases. Dr. Roger developed the Stellenbosch breeding system database as a postdoctoral fellow in the Faculty of Botany and Animal Science at SU. Professor Tiffany Knight, Professor Tia-Lynn Ashman, and Dr Janet Steets led the sPLAT Working Group, which created the GloPL database. Professor Mark van Kleunen and Dr Mialy Razanajatovo have created the Konstanz Breeding System Database. In the current study, all three databases have been integrated into the new database. It contains data from 143 plant families except Antarctica and 1,528 individual experiments representing 1,392 plant populations and 1,174 species from all continents.
The findings show that in the absence of pollen maters, one-third of flowering plant species do not produce seeds and half suffer a reduction of more than 80% in fertility. Therefore, although automatic delivery is common, it does not completely compensate for the decline in pollination services in most plant species.
“Recent studies have also shown that many pollen maters have diminished and some have become extinct. Our finding that many wild plant species are dependent on pollen maters is It shows that a reduction in pollen maters can cause great disruption to the natural ecosystem,“ says Dr Roger.
Professor Mark van Kleunen, co-author of the University of Konstanz, states that not all pollen maters have disappeared. Expected to have a knock-on effect on affected plants. Plant species can decline and cause more harm to animals and the human population that depends on those plants. Pollen maters are important not only for crop production, but also for biodiversity. “It also means that pollen-independent plants, like many problematic weeds, may spread further as pollen-crossers continue to decline,” Mark van Kleunen adds.
Another embarrassing factor is the positive feedback loop that occurs when pollinator-dependent plants decline or become extinct, said iDiv- and MLU-Alumna Dr Joanne Bennet, co-author of the University of Canberra, who curated the GloOL database. “A good landscape will adversely affect more pollen maters. This is because self-pollinating plants tend to produce less nectar and pollen.”
But according to Dr Roger, not everything is fate and darkness. Many plant is long-lived and opens the window for opportunities to recover pollen maters before the plants become extinct due to a shortage of pollen maters.
“There is a lack of high quality long-term monitoring data on pollen maters in Africa, including South Africa, but some work has begun on this point. Our findings further stimulate this type of research. We hope that it will be detectable. Pollen maters will decline and reduce their impact on biodiversity,” concludes Dr Roger.
Prof Tiffany Knight
Helmholtz Centre for Environmental Research – UFZ
Martin Luther University Halle-Wittenberg
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Phone: +49 341 9733158
Rodger, J. G., Bennett, J. M., Razanjatovo, M., Knight, T. M., Ellis, A. G. et al. (2021) Widespread vulnerability of plant seed production to pollinator declines. Science Advances, Vol. 7, No. 42. DOI: https://doi.org/10.1126/sciadv.abd3524