澳大利亚乔治布朗·达尔文植物园苏铁类植物资源收集与保护状况分析

黄玉源++Sharon+Wilson++Jane+Hempel2

摘 要：本文對澳大利亚乔治布朗·达尔文植物园苏铁类植物资源的收集、保护状况等方面进行了调查研究，调查结果表明：由于植物园是坐落在野生苏铁的主要分布地之一，因此该植物园在收集和管理苏铁类植物资源方面具有优势，已经收集和种植了70多种苏铁科和泽米铁科苏铁类植物，以及超过600多个苏铁植物植株。该植物园苏铁园建立于15年以前，种植的主要是澳大利亚本土分布的野生苏铁类植物，同时也种植有少量来自中国和其他国家的苏铁类植物。在植物园科技人员等全体职员的努力下，该植物园已经成为澳大利亚珍稀苏铁类植物资源重要的栖息地和保护地。本文对于植物园在苏铁植物资源的采集、栽培和管理的技术特点及优点进行了研究和分析，同时提出了一些建议。本研究对各地植物园在珍稀植物资源的收集和迁地保护等方面具有理论意义和实践的参考价值。

The Analysis on the Situation of Resources Collection and Conservation of Cycads in George Brown Darwin

Botanic Gardens，Australia

Huang Yu-yuan1， Sharon Wilson2， Jane Hempel2

（1College of Life Sciences， Zhongkai University of Agriculture and Engineering， Guangzhou，

Guangdong 510225， China； 2George Brown Darwin Botanic Gardens， NT 0820 Australia ）

Abstract： The situation on resources， collection and conservation of cycads in George Brown Darwin Botanic Gardens was investigated and analysed. The Botanic Gardens are located in a major region where cycads are found in the wild； therefore， the gardens have an advantage in cycad husbandry. They have collected more than 70 species in Cycadaceae and Zamiaceae， comprising about 600 adult individuals. The cycad garden has developed about fifteen years ago， in which the main planting species of cycads are native to Australia， while other species came from China and other countries. Because of the whole staffs efforts， the gardens have become an important place for rare cycad resources habitat and conservation in Australia. The paper summarizes and analyses the characteristics， merit of technique measures and some experiences on the collection and planting of cycads， and proposes some suggestions. This is a reference for gardens in respect to collecting and conserving rare plants.

1. Introduction

Cycads are most primitive seed plants in present time， are rare plant group， so they have important scientific value in the research on plant evolution， ecology and taxonomy； and have also the value in urban garden afforest and some manufactures of industry. Meanwhile， they also play the important and irreplaceable role in conserving local water and soil， maintaining local eco-system balance. Therefore， cycads were as important conserved plant by the international organizations such as IUCN and so on. Because they only exist about 300 species in the world， and many species individual numbers are few， with some human impact， so that the habitats ecological environment of many species were damaged， therefore they are the status which urge need reinforce conservation， artificial planting and reproduction， so that expand the populations.

Meanwhile， need increase the education of popularization of science and publicity， enhance people conscious of conserving cycads. Thereby， some regions where countries possessed wild cycads have built cycad gardens. Botanical gardens have important effects in aspect of urban ecological effect of vegetation， biological education and rare plant conservation[1，2]. This paper introduces and expounds the academic situation of cycads on introduced species， cultivation， layout and management， as reference for other botanic gardens in conservation engineering， and nursing research to cycads.

2. Darwin Botanic Gardens general situation

The Darwin Botanic Gardens were founded by Maurice Holtze， the first Government Gardener， on the present site in 1886.

Initially the Gardens were established to introduce and evaluate plants for economic uses in the Northern Territory. The Gardens now provide a window into the world of plants for our enjoyment， scientific research， conservation and education.

Since its establishment the Botanic Gardens have survived severe cyclones， major wildfires， and the direct effects of World War II.

The 42 ha of the Darwin Botanic Gardens are about 2 km north of the Darwin City Centre. Near the lower entrance off Gardens Road you can find the water fountain， floral displays， playground， barbecues and toilets.

This was the third attempt by European settlers of Darwin to establish a site where plants of economic importance could be tested for their suitability in the tropics[3]. Initially the collection of the gardens was focused on economic gardening and the ornamental plantings. The gardens were severely damaged during Cyclone Tracy in 1974， 89% of all plants were lost[4]. Restoration after the cyclone was led by George Brown， who had worked at the gardens since 1969 and served as curator from 1971 to 1990， and became Lord Mayor of Darwin in 1992 until 2002. The gardens were renamed in 2002 to recognise George Brown's contribution and 32 years service to the development of the gardens[4，5].

A network of paths connect the main features in the Gardens. Plant Display House： Contains a collection of tropical orchids， ferns， bromeliads， other exotic plants and special seasonal displays.

Palms and Cycads： A collection of approximately 500 individuals of cycad species have been planted. Most are located in Cycad garden and near or in the Rainforest Gully[6].

Aboriginal Plant Use Trails： Several self guided walks brochures are available from the Information Centre.

Rainforest Gully： Waterfall and ponds provide a setting for an established rainforest with an under storey of palms， shade plants and bamboo.

Children's Evolutionary Playground： This award winning playground will lead you through the changes in plant groups through time， while you enjoy the visual blend of science and creative art.

Native Top End Plants： Are planted throughout the Gardens， but particularly in areas such as the open woodland.

Baobab Collection： You can see all the baobab species in the world in this collection.

Mangroves And Coastal Plants： These are the basis of the Gardens' collections on the beach side of Gilruth Avenue. There are self guided walks in this area and a boardwalk， which forms part of a walking track to the Museum.

The air-conditioned Information Centre has posters， booklets and literature for information and sale. It also has informative botanical displays， including one on mangrove communities.

The Gardens have special areas suitable for social functions such as barbecues， weddings， festival and receptions.

3. The situation on introduced species， cultivation of cycads

In the Gardens， total collected and introduced cycad species 75 species， they main are the species which distributed in Australia， among about 10 species are wild and native in Northern Territory， and other species introduce formed North America， Central America and South America， East Asia， Southeast Asia and South Asia， Eastern Africa and Southern Africa etc.

In the process of constructing Cycad Garden， several tens species of cycad were cultivated in the garden.

In out of the Cycad Garden， many cycad species were also cultivated， most of them are different species to the Cycad Garden. Thus， formed a half natural status which cycads are concentrated distribution， meanwhile， in many other places they are random distribution. So that supplied more convenience for visitors can enjoy cycads. These cycads were cultivated in side of road and house， or in the center of grass or inside some forests. In some places， they were one species and several individuals located in there， some other places， they were several species with more individuals together connect formed a little area， so， formed similar to natural distribution scene， and combined with other plants constituted diversity and plentiful， good landscape.

Every species of cycad was given name plate， played better popularization of science and education effect， in the meantime， provided the condition for sciences research. In the Gardens， total have about 500 individuals of different species of cycads.

Although cycad garden was built about ago 10 years， but from 1978 began， the botanic gardens staffs have collected and introduced cycads， up to now， have already more than 30 years. Some scholars often went abroad and other places of Australia collected and introduced the different species of cycads for cultivation. They are Dr. Greg Leach and Dr. Harvey Ottely， Sharon Wilson， Jane Hempel， and several curator Gorge Brown， David Griffiths and so on also made important contribution for cycads introduction， cultivation， management， materials edited of popularization of science and publicity and academic researches in over the years.

In the Gardens， these cycads species name as follow：

In Cycad Garden， setting up detail materials exhibition on the distribution regions of wild species of cycad in Northern Territory， relative scientific knowledge； in the Information Centre， there were equipped with more biologic knowledge on cycads， some are paper materials， some are publicity wall newspapers. Played a very good education effect.

In respect of planting technology， staffs were more diligent maintenance and management， often using machinery work. In Cycad Garden， there are design formed flat ground region， and slope region， some areas cycads are as upper layer vegetation， have not other plants shielding or shielding fewer；some places are more shielding with higher trees of other plants.

At the stem base of some cycads， often piled up more chaff， fragmentary grass with other some fertilizer. Thus may ensured that cycad trees more absorb and preserve water and slowly resolve and release fertilizer supplying to cycad root. In Cycad Garden， 65% cycad individuals were used thus method management. Everywhere the cycads growth status were better， especially which located in more shield area or some slope areas， were better than those which located in more plain area. Of cause， these places species of cycad are different. Those formed Africa species of cycads such Genus Encephalartos， and some species formed Australia such as some species of Genus Zamia， they were growth better， despite of they located in the condition without any shielding.

On side of road and other places， however not used the method which at the stem base of some cycad， piled up chaff， fragmentary grass with other some fertilizer， these cycads were also growth well. In Cycad Garden， all areas were set automatic sprinkle water irrigation system. But in other places， most of cycad trees were without allocated the automatic sprinkle water system. They rely rain or sprinkle water vehicle obtained water.

These cycads planting and management engineering are a part of project of government of Northern Territory， in recent years， specially established the program of conserving cycads：Management Program for Cycads in the Northern Territory of Australia.

The all cycads in the Botanic Gardens were included important protection aim and the Cycad Garden was important constructing area.

In the northwest， have constructed a bigger sunshelter， as cycad Nursery， there are more cycads species， among of them are without species in out of the sunshelter， many of individuals were seedling， and some have already were adult individuals. Here as cycad seed storage， possessed very important effect. The equipment and preserve condition of Nursery are better.

4. Suggestion

（1）Few cycads growth status were weak， shall consider their wild habit environment， build a near to wild ecological environment for these cycads in Garden. Such as few species of cycad were growth weak， but these individuals were located in the site where were very few shielded by other trees， almost were received sunlight in whole day， so probable lead to cycads moisture deficiency and high temperature impact in summer. Therefore， maybe consider planting some other trees so that supply more shield for them according to the characteristics of wild ecological environment of these species.

（2） Some seedlings of cycads which cultivated in Nursery， if they have become adult， should successively transplant to field of the Gardens. These works are significant to expand individual number， and increase some species of cycad in field of Gardens which ever only planting in nursery， provide visitors enjoy the sight. Should consider carry out the plan of planting sites and design work of planting species combination.

（3）Appropriate strengthen the reproduction work to which introduced from abroad and other areas of Australia， especially the species which the individual are few， so that increase the number of species， reach the aim for best conservation.

Should strengthen the system record work to introduce and planting of cycads in everywhere， set up more system and entirely data base.

（4） To the situation which every species growth and reproduction， especially which came from other countries or regions should make scientific research work； meanwhile， try to explore the different cultivation technique requirement for different species of cycad， supply academic field reference.

Acknowledgment

We thank Dr. Harvey Ottley and David Griffiths， Director of the Gardens for help and support to the investigation work.

References

[1] Zhao G.Y. On the role of botanical garden in the construction of urban environment [J]. Shanxi Forestry，2011（1）：37-38.

[2] Fang B.C.， Qiu F. Y. The status and function of the botanical garden in city construction[J]. Hunan Forestry Science & Technology，2013，40（1）：119-121.

[3] NT Department of Natural Resources， Environment and the Arts. Darwin Botanic Gardens - About Us.

[4] NT Department of Natural Resources， Environment and the Arts. Darwin Botanic Gardens - George Brown.

[5] “NT Place Names Register”. Northern Territory Government. Northern Territory Lands Group.http：//www.ntlis.nt.gov.au/placenames/ view.jspid=3085.Retrieved 2008-07- 27.

[6] NT Department of Natural Resources， Environment and the Arts. Darwin Botanic Gardens - The Collection.