The Role of Botanic Gardens in Conservation of Medicinal Plant Species: A Case Study of Entebbe Bontanic Gardens
A botanic garden is an institution holding documented collections of living plants for the purposes of scientific research, conservation, display and education. A botanic garden has been defined as a garden containing scientifically ordered and maintained collections of plants, usually documented and labeled, and open to the public for the purposes of recreation, education and research.
Medicinal plant species are those that provide people with medicines to prevent diseases, maintain health or cure ailment. Therefore medicinal plants are important in the well being of people yet most people are not aware about these species or their medicinal value. Examples of these plants include Aloe vera, Hydnocarpus kurzii, Azadirachta indica and many others.
Medicinal plant species are of great value to mankind and other animals but not much emphasis is laid on their conservation especially ex-situ conservation given their ever dwindling natural habitats. Conservation of medicinal plants involves the sustainable utilization of medicinal plant resources that is in such a way that they satisfy the needs of today’s generation without hindering the ability of tomorrow’s generations to satisfy their own needs. This can easily be simplified as; “when you are eating today, remember to leave some for those who will be there tomorrow”
These species are mostly being threatened by harvesting practices incompatible with their survival or habitat degradation due to land use changes in favor of the development paradigm. The ever dwindling natural habitats of these medicinal plants have left only a choice of ex-situ conservation. This ex-situ conservation falls under the programmes of institutions such as botanic gardens that are encouraged by the Convention on Biological Diversity framework
Given that botanic gardens all over the world have always been closely linked to ex-situ conservation of medicinal plants, this review will examine the history of botanic gardens and their role in conservation of medicinal plants, the different strategies used in conservation of medicinal plants and a case study of the Entebbe Botanic Gardens in Uganda.
History of Botanic Gardens and their Role in Conservation of Medicinal Plants
Botanic gardens have in Western tradition been intimately involved in the cultivation of medicinal plants since their earliest beginnings. The first botanic gardens were medicinal or herbal gardens attached to faculties or schools of medicine created for provision of medicinal plants for study by students and for actual production of drugs.
The history of these botanic gardens is closely linked to the history of botany its self. This means that these gardens have for a long time been involved in plant cultivation and research programmes involving different species of flora. In particular, these botanic gardens have a long history of involvement with medicinal plants and with movements of other species of plants around the globe.
In the 16th century, Italian Botanic Gardens of Pisa, Padua and Florence, the later still called today the Giardino dei Semplici (garden of simples), were medicinal gardens attached to faculties or schools. There is also a long link between medicine and the botanic gardens in Asia. At the famous cultural site of Sigiriya in Sri Lanka, dating back to the fifth century AD, excavation has revealed the well preserved remains of very extensive, formally laid out, pleasure gardens, and historic records indicate that there was once a garden for medicinal plants.
The role of Botanic Gardens in conservation of medicinal plants can further be traced to the 18th century botanic gardens of the Jardin des Apothicaires which grew medicinal plants for the chests of doctors of ships sailing from the port and would in turn receive new plants, medicinal and others from abroad following a Royal Edicit signed at Versailles requiring captains and merchant mariners of Nantes to bring back all new plants found on their trips to foreign countries and the French colonies of America.
In the 1970s, botanic gardens started putting allot of effort into ex-situ conservation of medicinal plants. The Convention on International Trade in Endangered Species of wild Fauna and Flora (CITES) was signed in 1973 and major botanic gardens at the time such as the Kew Botanical Gardens played a major scientific and advisory role in conservation of medicinal plant species that were protected by the convention at the time. The Botanic Garden Conservation Secretariat (BGCS) was then established by the World Conservation Union (IUCN) in 1987 with the aim of coordinating the plant conservation efforts of botanic gardens around the World. It maintains a data base of rare and endangered species that are conserved and protected in botanic gardens around the Globe. The above mentioned facts are a reminder of the close relationship that existed between botanic gardens and conservation of medicinal plants. In fact Botanic Gardens and conservation of medicinal plants are very closely and inevitably linked throughout time.
The Role Botanic Gardens Play in Conservation of Medicinal Plants Today
Hundreds of millions of people, mostly in developing countries, derive a significant part of their subsistence needs including income from gathered plant and animal products. These products can be aesthetic, medicinal or commercial. It has been estimated that 35000-70000 species of plants have been harvested and used at one time or another for medicinal purposes. Harvesting incompatible with the natural re-population processes of individuals of medicinal plant species can lead to extinction or loss of Bio-diversity. This is where botanic gardens come in as ex-situ conservation institutions to preserve and protect these plants outside their natural habitats. In today’s world, many thousands of species of tropical flora are used in medicine yet our scientific knowledge that is relevant to sustainable utilization of these plants is limited. Furthermore, our knowledge to propagate and cultivate these medicinal plants is also equally substandard. This is where the role of botanic gardens in conservation of medicinal plants must be stressed as they have the capability to propagate and cultivate these plants. With the increased realization that some wild species are being over-exploited and their habitats dwindling, a number of agencies are recommending that wild species be brought into ex-situ conservation systems.Clearly, botanic gardens, with their expertise in gardening and other botanical disciplines, can often play useful roles in helping to select and develop varieties for cultivation, and in undertaking research on techniques for propagation and cultivation. The aim is to produce sustainability in supply of plant material for the manufacture of medicines.
Botanical gardens also play a role in helping to develop back-up facilities for ex situ conservation of threatened medicinal plants. This could be through providing expertise to land-holding agencies or individuals for the development of small nurseries at each in-situ site, so as to propagate the species and reintroduce them into nature where populations are low. Possibly, Botanic Gardens could also assist through the development of germplasm banks such as seed collections, though medicinal plants are not high on the list of ex-situ conservation programmes of this type at present.
Botanic gardens play a vital role in conservation of medicinal plants since they increase the level of awareness about medicinal plants and their values on top of conducting ex-situ cultivation programmes and maintaining collections of these plant species.
A Case Study of Entebbe Botanic Gardens and their Role in Conservation of Medicinal Plants
Entebbe Botanic Gardens are situated on the Northern shores of Lake Victoria (long. 32º29'E., at. 0º04' N.). They receive an average annual rainfall of 1,626 mm and lie at 1,134 m above sea-level. The garden lies within the township of Entebbe in the southern part of Uganda and 33.80 kilometers from Kampala, the capital city of Uganda. The gardens which cover an area of 100.57 acres are said to have an estimate of over 150 plant species of medicinal value. The Entebbe Botanic Gardens play a vital role in the conservation of these plant species.
Map Showing Location and Site of Entebbe Municipality and the Entebbe Botanic Gardens
The Entebbe Botanic Gardens are the only nationally recognized botanic gardens in Uganda. They were created in the year 1898 after the first British colonialists came to Uganda. The aim was to maintain collections of crops important in agricultural production and other commercial uses. The botanic gardens were very active in plant introduction from many parts of the world. Crop species of foreign origin such as cocoa, coffee, tea and rubber were introduced and evaluated. Uganda's varied agro-climatic conditions offered a good opportunity for these plants to grow and they have become the main cash-crops of the country. The gardens have until recently served simply as an area for public recreation and enjoyment, with no attempt made to develop its considerable potential as a place for systematic collection of plants, centre for research and education.
It is important to note that national botanic gardens like those of Entebbe were not only created for the above mentioned purposes but also for the conservation of endangered flora as listed by the IUCN Red List, International Plant Protection Convention, CITES and Convention on Biological Diversity (CBD). The development of conservation strategy for Botanic Gardens has evolved over the past few years following a series of key events such as the 1975 and 1978 Kew conferences and the Las Palmas conferences on botanic gardens and the conservation strategy held in 1985. One of the botanic gardens following this evolved conservation strategy is the Entebbe Botanic Gardens.
The Entebbe Botanic Gardens have always aimed at achieving the following objectives;
- To integrate conservation activities with agricultural and genetic resources development.
- To enhance the educational and recreational potential of the gardens through the development of facilities and services that will benefit both residents and tourists alike.
- To encourage and enhance public involvement in the work of the botanic garden and extension of the work of the botanic garden into the community.
- To undertake screening of native plants for utility and possible economic production.
- To put up a scheme to establish collaboration with relevant institutions in the development and production of native wild plant species of economic and educational value for example medicinal plants, wild fruits, fibers, spices, fuel-wood and forage crops.
- To establish Ethno-Botanical Gardens, if possible in each district.
The Entebbe Botanic Gardens (EBG) together with Uganda National Gene Bank (UNGB) are under the Plant Genetic Resources Centre (PGRC) which is an institution under the National Agricultural Research Laboratories (NARL) of the National Agricultural Research Organization (NARO).
The Entebbe Botanic Gardens employs a number of different strategies in conservation of medicinal plants including in-situ conservation and re-introduction programmes, biotechnology and gene banks, education and sensitization programmes, research programmes and ex-situ conservation.
The Different Medicinal Plants in Entebbe Botanic Gardens
The Entebbe Botanic Gardens are said to be an ex-situ conservation site for more than 122 medicinal plant species. The most commonly known medicinal plant species in these botanic gardens include Aloe vera, Prunus africana, Bidens pilosa, Cannabis sativa and Catha edulis among others.
Table Showing the Medicinal plants in the Entebbe Botanic Gardens
|Family/species name||Source||IUCN conservation status|
|1||Acanthus pubescens||Uganda||Not evaluated|
|2||Asystasia schimperi||Uganda||Not evaluated|
|3||Brillantaisia mahonia||Uganda||Not evaluated|
|4||Justicia betonica||Uganda||Not evaluated|
|5||Aerva lanata||Uganda||Not evaluated|
|6||Celosia trigyna||Uganda||Not evaluated|
|7||Anacardium occidentale||Tropical America||Not evaluated|
|8||Spondias lutea||Tropical America||Not evaluated|
|9||Funtumia africana||Tropical Africa||Not evaluated|
|10||Plumeria rubra||Tropical Africa||Not evaluated|
|11||Rauvolfia vomitoria||Tropical Africa||Not evaluated|
|12||Vinca rosea||North America||Not evaluated|
|13||Schefflera actinophylla||New Guinea||Not evaluated|
|15||Steganotaenia araliaceae||Tropical Africa||Not evaluated|
|16||Asclepias semilunata||Uganda||Not evaluated|
|17||Kigelia moosa||Tropical Africa||Not evaluated|
|18||Bischofia javanica||Tropical Asia||Not evaluated|
|19||Adansonia digitata||East Africa, Sudan||Not evaluated|
|20||Ceiba petandra||Tropical Asia||Not evaluated|
|21||Durio zibethinus||Malaysia||Not evaluated|
|22||Cannabis sativa||Tropical Africa||Not evaluated|
|23||Cleome gynandra||Uganda||Not evaluated|
|24||Drymaria cordata||Tropical Africa||Not evaluated|
|25||Catha edulis||Tropical Africa||Lower Risk/least concern|
|26||Chenopodium opulifolium||Tropical Africa||Not evaluated|
|27||Combretum paniculata||Tropical Africa||Not evaluated|
|28||Zebrina purpussii||Uganda||Not evaluated|
|29||Commelina bengalensis||Uganda||Not evaluated|
|30||Ageratum conyzoides||Uganda||Not evaluated|
|31||Aspilia africana||Uganda||Not evaluated|
|32||Bidens pilosa||Uganda||Not evaluated|
|33||Crassocephalum sp||Uganda||Not evaluated|
|34||Dichrocephala integrifolia||Uganda||Not evaluated|
|35||Eriangea tomentosa||Uganda||Not evaluated|
|36||Microglossa angolensis||Uganda||Not evaluated|
|37||Senecio discifolius||Uganda||Not evaluated|
|38||Sigesbeckia orientalis||Uganda||Not evaluated|
|39||Solanecio cydonifolius||Uganda||Not evaluated|
|40||Solanecio mannii||Uganda||Not evaluated|
|41||Tagetes minuta||Uganda||Not evaluated|
|42||Vemonia amygdalina||Uganda||Not evaluated|
|43||Hewittia sublobata||Uganda||Not evaluated|
|44||Kalanchoe pinnata||Uganda||Not evaluated|
|45||Cardamine trichocarpa||Uganda||Not evaluated|
|46||Cucurbita maxima||Uganda||Not evaluated|
|47||Momordica foetida||Uganda||Not evaluated|
|48||Dioscorea alata||Uganda||Not evaluated|
|49||Dracaena steudneri||Tropical Africa||Not evaluated|
|50||Dracaena fragrans||Tropical Africa|
|51||Bridelia micrantha||Tropical Africa||Not evaluated|
|52||Croton megalocarpus||Tropical Africa||Not evaluated|
|53||Euphorbia heterophylla||Tropical Africa||Not evaluated|
|54||Euphorbia hirta||Tropical Africa||Not evaluated|
|55||Euphorbia tirucalli||Uganda||Least Concern|
|56||Jestropha curcas||Tropical America||Not evaluated|
|57||Jatropha multifida||America||Not evaluated|
|58||Phyllanthus reticulatius||Tropical Africa||Not evaluated|
|59||Ricinus communis||Uganda||Not evaluated|
|80||Sapium ellypticum||Tropical Africa||Not evaluated|
|81||Tragia benthami||Uganda||Not evaluated|
|82||Hydnocarpus anthelimintica||Siam||Not evaluated|
|83||Hydnocarpus petandra||India||Not evaluated|
|84||Digitaria abyssinica||Uganda||Not evaluated|
|85||Imperata cylindrica||Uganda||Not evaluated|
|86||Hoslundia opposita||Uganda||Not evaluated|
|87||Osimum suave||Uganda||Not evaluated|
|88||Tetradena riparia||Uganda||Not evaluated|
|89||Cinnamomum camphora||China||Not evaluated|
|90||Acacia camphylacantha||Tropical Africa||Not evaluated|
|91||Acacia hockki||Tropical Africa||Not evaluated|
|92||Baikiaea insignis||Tropical Africa||Not evaluated|
|93||Cassia alata||Tropical Africa||Not evaluated|
|94||Cassia fistula||Tropical Africa||Not evaluated|
|95||Cassia spectabilis||Tropical Africa||Not evaluated|
|96||Craibia elliotii||Uganda||Not evaluated|
|97||Cynometra alexandri||Tropical Africa||Not evaluated|
|98||Desmodium mauritianm||Tropical Africa||Not evaluated|
|99||Erythrina abyssinica||Tropical Africa||Not evaluated|
|100||Erythrophleum suaveolens||Tropical Africa||Not evaluated|
|101||Indigofera spicata||Tropical Africa||Not evaluated|
|102||Leucaena glauca||Tropical Africa||Not evaluated|
|103||Myroxylon balsamum||Tropical Africa||Not evaluated|
|104||Pseudanthistiria hookeri||South America||Not evaluated|
|105||Saraca indica||Tropical Africa||Not evaluated|
|106||Glorisa suberba||Uganda||Not evaluated|
|107||Anthocleista vogeliplanchon||Tropical Africa||Not evaluated|
|108||Albutilon mauritianum||Uganda||Not evaluated|
|109||Albutilon zanzibaricum||Uganda||Not evaluated|
|110||Azanza barckeana||East Africa||Not evaluated|
|111||Sida cordifolia||0||Not evaluated|
|112||Melia dubias||Asia||Not evaluated|
|113||Azadirachta indica||Tropical Asia|
|114||Melia azedarach||Asia||Not evaluated|
|115||Artocarpus heterophyllus||Tropical Asia||Not evaluated|
|116||Milicia excelsa||Tropical Africa||Lower Risk/ near threatened|
|117||Ensete ventricossum||Tropics||Not evaluated|
|118||Amomis caryophyllata||America||Not evaluated|
|119||Callistemon salignus||Australia||Not evaluated|
|120||Eugenia uniflora||Australia||Not evaluated|
|121||Eucalyptus maideni||Australia||Not evaluated|
|122||Pimenta officinalis||Tropical America||Not evaluated|
|123||Biophylum petersianum||Uganda||Not evaluated|
|124||Areca catechu||Tropical Asia||Not evaluated|
|125||Phytolacca dodecandra||Tropical Africa||Not evaluated|
|126||Sesamum angolensis||Tropical Africa||Not evaluated|
|127||Plantago palmata||Tropical Africa||Not evaluated|
|128||Plumbago zeylanica||Tropical Africa||Not evaluated|
|129||Oxygonum sinuatum||Tropical Africa||Not evaluated|
|130||Portulaca oleracea||Tropical Africa||Not evaluated|
|131||Clemantis hirsuta||Tropical Africa||Not evaluated|
|132||Prunus africana||Tropical Africa||Vulnerable|
|133||Nauclea latifolia||West Tropical Africa||Not evaluated|
|134||Pentas zanzibarica||Tropical Africa||Not evaluated|
|135||Rubia cordifolia||West Africa||Not evaluated|
|136||Citrus medica||Southeast Asia||Not evaluated|
|137||Teclea nobilis||Tropical Africa||Not evaluated|
|138||Harrisonia abyssinica||Tropical Africa||Not evaluated|
|139||Capsicum frutoscens||Tropical Africa||Not evaluated|
|140||Datura stramonium||Tropical Africa||Not evaluated|
|141||Nicotiana tabacum||Uganda||Not evaluated|
|142||Solunum aculeastrum||Uganda||Not evaluated|
|143||Solunum camphylacanthum||Uganda||Not evaluated|
|144||Solanum macranthum||Tropical Africa||Not evaluated|
|145||Solunum nigrum||Uganda||Not evaluated|
|146||Solunum nidiflorum||Uganda||Not evaluated|
|147||Philadelphia spp||Uganda||Not evaluated|
|148||Lantana camara||Tropical Africa||Not evaluated|
|149||Priva leptostachya||Uganda||Not evaluated|
|150||Clerondendrum myricoides||Uganda||Not evaluated|
|151||Aloe vera||Tropical Africa||Not evaluated|
|152||Encephalartos hildebrandtii||Uganda||Not evaluated|
|153||Aframomum sanguineum||Tropical Africa||Not evaluated|
|154||Aframomum melegueta||TropicalAfrica||Not evaluated|
Finally, in addition to maintaining a large collection of medicinal plants, the Entebbe Botanic Gardens have also helped in increasing the level of awareness about these species as the facility gets a considerable number of visitors every year. These guests gain considerable amount of knowledge about medicinal plant species and their conservation as the facility has educational programmes for these visitors.
Botanic gardens have always and will always be intimately linked to medicinal plant conservation and because of this, stake holders in conservation should ensure that they always have the instruments and tools to carry out their activities as this will undoubtedly promote sustainable use and conservation of these species.
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