The role of botanic gardens
Botanic gardens are uniquely positioned to help address the issues relevant to restoring ecosystems. They provide knowledge and expertise in plant taxonomy, horticulture, biodiversity inventory, conservation biology, restoration ecology and ethnobotany – all key elements for achieving successful restoration.
Botanic gardens also collectively serve as a global repository for documented plant material, with at least one-third of all flowering plants maintained in living collections or seed banks. Utilizing knowledge gained from these collections, related herbaria and libraries, and combined with landscape knowledge from field surveys and ecological research, botanic gardens bring the understanding necessary to ensure that restoration leads to adequate taxonomic diversity and incorporates appropriate genetic provenance.
Botanic gardens can therefore restore diverse and ecologically resilient places, avoiding the dangers and pitfalls associated with growing inappropriate plants in the wrong environment.
Botanic gardens are also well-placed to raise awareness amongst the general public of the need for, and benefits that can be derived from, successful ecological restoration projects. The new Ecological Restoration Alliance of Botanic Gardens will thus also address the need for greater political commitment, awareness and participation in restoration work.
Examples of current projects:
Beach restoration increases Hawaiian green sea turtle nesting - Ten years ago, the National Tropical Botanic Garden began an ambitious restoration of the beach and adjacent coastal forest in an area known as Lāwa‘i-kai in Hawaii. The project’s first goal was to remove the invasive alien grasses, which had crowded out most native plants and hardened the beach’s substrate so that the threatened Hawaiian green sea turtle was no longer able to nest. The restoration plan carefully followed fossil and historical evidence to design vegetation that would have existed on the site about a millennium ago – shortly after Polynesian arrival. Evidence from excavations at a nearby cave, as well as 6,000-year sediment cores from the area’s own estuary and a dozen other paleo-ecological and archaeobotanical sites around Kaua‘i, were combined with present and historical records for plants to generate a very long species list. Many of those plants, including rare palms, trees, and shrubs endemic to the island, now thrive on the three-acre restoration and this restored habitat has resulted in increased turtle nesting activities..
Re-growing Rio - The magnificent 200 year old Rio de Janeiro Botanic Garden has extensive experience in reforestation of the Atlantic Forest of Brazil one of the world’s global biodiversity hotspots. Now the Garden is collaborating with Rio municipality on forest enrichment of hills and slopes of the city with endangered, rare, and endemic species. The main goal is to enrich the 10 to20 year old restored forests not only with other tree species, but also with bushes, epiphytes, lianas, herbs from the Atlantic Forest bringing native biodiversity back into the city.
Restoring Kenya’s Upland Forest – Clearing species-rich upland forest for tea plantations and associated eucalyptus forests has been going on since the early 1900's. More recently in central Kenya, non-protected forests are felled for charcoal, subsistence agriculture, commercial flower growing and residential development, Less than 2% of the original forests remain in the tea-growing areas north of Nairobi and they have been replaced with plantations of non-native eucalyptus, Australian acacia (Wattle), cypress and pine. Restoration of upland forest at Brackenhurst Botanic Garden (outside of Nairobi) in just 12 years has replaced exotic trees with a 30+ foot tall native overstory that shelters lianas, orchids and a species-rich understory. The garden now has over 1500 species of East African native plants. In addition, only while only about 10 species of birds are supported by the exotic trees, the restored forest is habitat to over 170 species of birds recorded since the project began. It has trained and employed local people, provided livelihoods in an area of high unemployment and is becoming a model for a new East African biodiversity, restoration and hardwood forestry initiative.
Hyperarid Woodlands in Southern Peru - The ancient Nasca people drove themselves to near-extinction by replacing woodlands of the huarango tree with intensive farming practices. Without huarango trees to release moisture to the atmosphere, the local climate became progressively drought-prone, thus dooming the agriculture in this very arid part of southern Peru. Oliver Whaley and William Milliken (Royal Botanic Gardens, Kew) have been working with local people, government and industry to propagate tens of thousands of huarango trees and to then recreate the climate-changing woodlands. For more than five years, school children and their parents have learned about the importance of these native woodlands to their own economic well-being, and have become major partners in re-establishing the woodlands and conserving remnant stands of native vegetation.
Healing a Surface Mine Site in Western Australia - Growing global demand for raw materials will accelerate mining of coal, aluminum and rare earths, especially in Australia. These deposits often lie below species-rich forests and shrublands that are of great conservation value. Kings Park and Botanic Garden in Perth has been working with mining companies to find ways of replacing the soil and forests using cutting-edge science as well as innovations in the mining process. It is now possible to restore over 90% of the plant species found in a mined Jarrah Forest, producing a complex forest structure in 15 to 20 years that is suitable as habitat for rare birds and mammals. Just as important, the restored forest provides a much better watershed for capturing the available precipitation than the forestry-type plantations that were commonly installed in the past.
Integrating restoration into Protected Areas management in Madagascar –Madagascar is widely recognised as a globally important biodiversity hotspot with one of the world’s more highly threatened floras. Over the last decade, the Missouri Botanical Garden’s programme in Madagascar has incorporated ecological restoration into the design and management of a network of 11 new community-based conservation initiatives established over the last decade throughout the island. Typically this involves reducing pressure on areas of partially degraded forest to facilitate natural regeneration, and where appropriate, planting selected native tree species using seedlings from local provenances propagated in on-site village nurseries. Pioneer tree species are typically used in degraded situations to provide conditions under which species of later successional stages can germinate and develop, complemented by “enrichment” planting with useful, over-exploited native species chosen by local stakeholders. Research on the best adapted species and the best techniques and strategies to use is underway by MBG staff, local collaborators and expatriate volunteers from the Restoring Natural Capital Alliance network, whose Secretariat is based at MBG. Efforts are also underway with local communities to improve livelihoods, develop alternative sources of food and fuelwood, and improve income-generation and thereby reduce pressure on the forests and raise the local standard of living.
Restoring native habitats of the U.S. Midwest – The Missouri Botanical Garden has developed a 2,400 acre (970 ha) reserve, Shaw Nature Reserve, since 1925. Originally intended as a garden-annex and arboretum, from its earliest days “the Arboretum” became known for its native woodlands and wildflowers. Since 1980 its purpose has developed to become an important regional centre for environmental education and conservation of native biodiversity and ecosystems of the Missouri region. Extensive areas of restored tallgrass prairies, wetlands, woodlands, glades (xeric meadows) and riparian areas have been created or restored. An experimental approach to vegetation management practices has been employed, with the aim of developing models and protocols applicable more widely. Management techniques practiced include controlled burning, invasive species clearing with national youth volunteer groups, and aerial spraying of invasive plant species. A demonstration garden featuring over 700 plant species native of the region has been created, and a native plant seedbank is under construction.