Plant distributions and migrations are greatly affected by climate change. Locally, in less than two decades, we have seen the USDA hardiness zones of Missouri (and most of the country) bumped up an entire category, meaning that we can now grow plants requiring warmer weather and can no longer grow plants requiring cooler temperatures. Changes of plant species’ distributions and their migrations with climate change are modeled at the Missouri Botanical Garden by various researchers and our collaborators (Ozarks, Midwest, Madagascar, Paramo, Himalayas, GLORIA).
Our unparalleled plant information database, TROPICOS, is prominently used to model these effects of climate change on plant species. In the Himalayas, the Andes, and Africa, we study changes in plant communities and biodiversity with climate change as a dominant research theme at the Missouri Botanical Garden and among our collaborators. Unfortunately, among the plants most negatively affected by climate change, because of their limited distributions and inability to migrate, are threatened endemic plants (Madagascar, Himalayas, Andes); while those plants that can most easily adapt and migrate are often invasive species and weeds (Midwest, Madagascar, Himalayas). These dramatic changes in plant distributions with climate change are altering our living planet as we know it, and understanding these changes is crucial for managing our future.
Plant phenology and pollination are also altered by climate change. The former Director of the Missouri Botanical Garden, Dr. Edgar Anderson, took weekly walks around the Garden and the Shaw Nature Reserve in the 1950s, noting when plant species were in flush, flower and fruit (called phenology). These data were recollected in the 1970-90s and now again recently. With climate change, leaf flush, flowering and fruiting are becoming earlier, while leaf fall is later. Plant pollination is also being affected by these changes linked to climate change.
Similar trends are found in other parts of the world. For example, the center of diversity of Rhododendrons is in the eastern Himalayas where species are found at different elevations and flower at different times. With climate change these spatial and temporal patterns of Rhododendrons are changing along with their pollination.
Plant population ecology is altered significantly by climate change. Plant populations increase or decline depending on reproduction, germination, growth and death. All of these factors have been shown to vary with climate change meaning that healthy, sustainable plant populations may become threatened as their environments change or that previously threatened populations may now be tipped toward extinction.
In the Midwest, the Missouri Botanical Garden is measuring critical plant population variables for threatened species, including seed dormancy, germination and viability in current and future climates. Will these already threatened species become extinct with climate change? Snow Lotus, a valuable Tibetan medicinal plant, is threatened by both over-harvest and climate change. The Missouri Botanical Garden is studying these conditions and developing sustainable harvest and conservation strategies for these beautiful, endemic, and threatened endemics.
Adaptation, mitigation and carbon sequestration strategies for climate change being developed at the Missouri Botanical Garden dovetail with the Garden’s enduring leadership in conservation of biodiversity. Plants are the one sure carbon negative resource of our planet: plants take up carbon dioxide and emit oxygen. Plants are the solution to conversion of the excess carbon dioxide that causes global warming. The Missouri Botanical Garden is in a unique position to lead the global effort to mitigate climate change through plants and to sequester carbon in plants.
Plant conservation and conservation of natural vegetation assure that the carbon sequestered by plants remains in those plants or in the soil organic matter rather than emitted into the atmosphere, which is what happens with deforestation. Tropical rainforests and other biomes store immense quantities of carbon; these biomes are being conserved as part of the mandate of the Missouri Botanical Garden.
With climate change, however, often plants are no longer adapted to the areas they now inhabit (see Plant Distributions and Migration above). They must move with their habitats or go extinct. Several projects at the Missouri Botanical Garden are monitoring these plant responses and enabling plant migrations through conservation of corridors of natural vegetation (Midwest, Madagascar). Native plant gardens (Midwest, Costa Rica) also can conserve plants and help extend their ranges.
People too must adapt to climate change and plants are one of our primary tools for adaptation. Worldwide plants are the kingpin of human livelihoods. With climate change, agriculture and health are adversely affected (Himalayas). People must adapt through uses of plant resources often unfamiliar to them. The Missouri Botanical Garden is in a unique position to provide vast amounts of information on plant resources and to offer leadership in helping people adapt to climate change.
Training and Capacity Building on climate change, adaptation, and mitigation are provided locally through Earthways and Education at the Missouri Botanical Garden. Internationally, our scientists work with in-country researchers and collaborators to strengthen scientific and technical capacity and train governmental, non-governmental and local organizations about climate change (Madagascar).
In many parts of the world people see, feel and experience drastic effects of climate change but have little or no idea of the causes, much less the solutions. The Missouri Botanical Garden takes very seriously our role to promote understanding of climate change and of our collective condition on Earth to better address solutions.
The Missouri Botanical Garden provides leadership (Raven, Wyse-Jackson) nationally and internationally for environmental policy development, providing scientific advice to inter-governmental organizations, governments and non-governmental organization on climate change. For example, the Copenhagen Accord recognizes “the crucial role of reducing emission from deforestation and forest degradation and the need to enhance removals of greenhouse gas emission by forests.”
The Missouri Botanical Garden is a leader not only in forming policy to prevent tropical deforestation but also in reducing emissions from deforestation and forest degradation in developing countries (REDD, Himalayas). With our expertise in plant research and conservation, the Missouri Botanical Garden boasts highly qualified and experienced scientists and unique resources with which to develop science based policy on climate change.