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Assuming the Responsibility: Intergration of Conservation in the Garden and the Community

Dr John Cortes, FLS, MIEEM, Director,
Gibraltar Botanic Gardens

Home | Contents | Introduction | The Problem | The Garden | The Philosophy | The Practice | The News Media | The Schools | Involvement | Case Studies | Conclusions | References | Appendix | Figure 1 | Table 1 | Slides


Gibraltar, popularly known as "The Rock" should not have a botanic garden. It really shouldn't have much of natural history importance at all. Being such a small place (approximately 6.5km2), so densely populated (28,000 inhabitants) and for so long (continuously since the Moorish occupation in AD711) there should hardly be space to move. Having had a strategic military importance for so many centuries, most of it should be covered in installations of war, while situated as it is in one of the most touristically developed zones of Europe - the south western Mediterranean at the tip of the Costa del Sol - any spare ground there may have been after all that should be a tourist complex (there were approximately 4 million tourists visiting in 1997). But Gibraltar is none of that and yet a bit of all of it. Military use and geology have in fact kept much of the area free of urban development while politics and economics have restricted growth of the tourist resort.
The Rock is a mass of limestone and dolomites, with intrusions of softer materials like shales (Rose & Rosenbaum, 1990). The whole of the east side of Gibraltar is essentially a sea cliff, rising at the centre to 396m almost sheer from the sea, and ascended along 1500m of it to about 250m by a slope of partially consolidated windblown sand. The western slope is gentler and largely vegetated with a cover of Mediterranean matorral at various stages of development (Cortes 1994a, Linares 1996).

The vegetated area is a refuge for resident birds and other wildlife, including at least four species of bats (Santana 1996), 5 of snakes , 8 of lizards (Cortes, in prep.), and one of wild non-human primate, the Barbary Macaque Macaca sylvanus. It is also important as a stop-over site for migratory birds, as are the flat stony terraces to the south (Cortes 1996). Overhead fly tens of thousands of birds of many families on migration between Africa and Europe twice a year.

Offshore, along the Straits of Gibraltar separating the Pillars of Hercules, fly migrating seabirds between Mediterranean and Atlantic. Beneath the waters migrate fish, cetaceans and turtles, while less mobile marine organisms include endemic sea slugs (Nudibranchia). Both the Rock of Gibraltar and the Straits of Gibraltar are listed as Important Birds Areas (Grimmett & Jones, 1989), and the waters of Gibraltar will shortly be proposed as a site under the Ramsar Convention. At the latest count (Linares et al 1996) there were 530 species of flowering plants recorded on the Rock, including seven of special interest as endemic taxa or species not recorded elsewhere in Europe. But habitat loss has resulted in the known loss of 76 species between 1914 and 1994 (Cortes 1994b).

Some of the habitats are of types listed as in need of protection under the European Union's Habitats Directive (GONHS 1994 & Appendix I) and have in fact been collectively proposed as Special Areas of Conservation under this Directive and as Special Protected Areas under the Birds Directive. Since its creation in 1976, but more actively since 1987, Gibraltar's natural assets have been watched over by the Gibraltar Ornithological & Natural History Society (GONHS), the Rock's only environmental non-governmental organisation (NGO). This Society, for example, achieved the updating of wildlife trade legislation to incorporate the latest CITES requirements in 1990 and, in 1991, drafted the Nature Protection Ordinance and got it approved by Gibraltar's legislature. By chance, this was the year of the launch of the Gibraltar Botanic Garden project.

This garden was opened originally as the Alameda Gardens in 1816. From the very start it was a Community garden. General George Don, Lieutenant Governor at the time saw the need for a garden for the recreative use of civilians and military in what was a small besieged territory where all the countryside was out of bounds to the population. Using money raised through public lotteries and theatrical performances, the Alameda Gardens were planted and opened and became the recreational hub of the 19th Century British Crown Colony.

The Alameda Gardens soon captured the attention of visitors to Gibraltar and received praise in a number of botanical books and travelogues (e.g., Kelaart, 1846). For a number of reasons, the gardens were all but abandoned in the 1970s and for about fifteen years deteriorated badly. In 1991 the Government of Gibraltar decided to take steps to reverse the decline and accepted a proposal from a newly created firm of environmental consultants and managers, Wildlife (Gibraltar) Ltd., to restore the gardens and convert them into a botanical garden. This paper is not about the history and progress of this new garden, nor of the work being undertaken there. It is a review of an aspect of this work, of how this emerging organisation has taken on the challenge and assumed the responsibility of playing a key role in incorporating conservation thinking into the running of a garden and in turn integrating botanic garden philosophy into the community as a whole.

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The Problem

Gibraltar is small. The population is growing. The economy is growing slowly but successive Governments have attempted - and continue to try - to increase investment in industry. The need for housing has been well catered for, for the moment, on reclaimed land and re-allocated buildings formerly used by the departing military. But greedy developers see every patch of green land as an opportunity to build expensive residences and make their money. There is no option to exploit sustainably against these odds. Here exploitation means destruction. Pressure on land is therefore great. There is no traditional use of the small extent of "countryside" in Gibraltar, a total of about 197 ha (most of which since 1993 is within the unsatisfactorily managed Upper Rock Nature Reserve) and so the drive to protect it comes exclusively from conservationists.

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The Garden

The Alameda Gardens - now also known as the Gibraltar Botanic Gardens - is privileged in that it is not threatened by development. It covers 5.5 ha on the lower western slope of the Rock of Gibraltar. It rises from about 35m to 60m above sea level, and although now about 400m from the sea behind an industrial dockyard, it was at one time virtually on the shore. The garden's natural soil is sand, predominantly of wind blown origin (Rose & Rosenbaum, 1990) known geologically as the Alameda Sands, of a slightly alkaline pH.

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The Philosophy

The garden follows the established and widely accepted aims and objectives of any bona fide botanic garden as recognised by Botanic Gardens Conservation International. It has assumed additional responsibilities to stop the loss of botanical diversity in the territory and, in the face of increasing pressure on green areas, to maximise garden areas, minimise the loss of green areas, and promote the use of native species in landscaping.

Management believes that it has to use its position as a focus of botanical and horticultural knowledge to influence thinking in the community as a whole, from the youngest child to the oldest decision maker. To gain this public support the garden in addition has to be well known and popular. And it has to lead by example. It therefore encourages wildlife. The use of pesticides is restricted to greenhouses and other enclosed areas or under strict control in cases of plagues. Birds and other wildlife are encouraged. Nest boxes for tits and treecreepers are provided as are bat boxes. Butterflies are also encouraged and there is a particularly important population of two-tailed pasha Charaxes jasius whose food plant in Gibraltar, in the absence of its preferred Arbutus unedo is the native Osyris quadripartita.

A recent innovation by natural colonisation has been the Monarch butterfly Danaus plexippus. Pine processionary caterpillar Thaumatopaea pityocampa control is attempted through the use of pheromone traps. The use of herbicides is also limited to very specific problems and locations. Indeed, in the case of at least one "weed", Ononis cossoniana, the garden is the only location where this species still occurs wild in Gibraltar. It is not only tolerated, but encouraged. Mined peat is not used, with the use instead of worm-worked compost and coir fibre and a small amount of the garden's own composted material. Publicity is regularly given to all these policies in the media as well as in the garden's publications.

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The Practice

The Alameda doubles up as a public park, which it has always been. As such it has the advantage of being well known in the community - much of the public has played in it as children or courted as youths. The expansion of its role into conservation has therefore been a logical step welcomed by the public. The Botanic Garden immediately offered use of its resources to the NGO (GONHS), becoming closely associated with its role and its botanical conservation work in particular. Its approach was to work with and assist the existing organisation and in no way threaten its status or position in the community. A shared address and shared aims, as well as joint work in plant and animal conservation have worked well. In the absence of a budget for much research and wider conservation, close work with the NGO has filled in many empty gaps and vacant niches. After years of neglect and inactivity, the garden soon became a focal point of conservation activity and a centre from which much more than garden management and plant conservation radiates.

The News Media

The garden promotes its activities, its problems and its successes in the media. Gibraltar has a television station, two radio stations, a daily newspaper and three weekly newspapers. Press releases are issued regularly on matters as diverse as vandalism, the recovery of an "extinct" endemic species, and the water shortage during the summer drought.

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The Schools

Being the only garden of substance in a Territory where virtually no-one has his own garden, it is a destination for school children of all ages from all schools. Nursery schools (under 5) bring their children for their first contact with flowers and birds, First schools (ages 5 - 8) have more formal sessions either using leaflets prepared by the gardens or part of their curriculum work on non-flowering plants or "mini-beasts", Middle schools (ages 9 - 11) look into flower structure and differences between monocots and dicots, while students in Secondary education use the growing reference library or man a weather station. Garden staff also lecture in the schools. In fact every school child in Gibraltar visits the gardens formally as part of his/her course at least twice during their school career.

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The crucial point is the aggressive involvement of the gardens in whatever happens in the Territory that is of relevance to plant conservation. The garden has a duty to use its knowledge and influence to promote its aims. The following case studies illustrate some of these points. In most of the cases the approach has been jointly with the GONHS.

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Case Studies

Saving Silene

Hardly anyone in Gibraltar knew about the Gibraltar Campion Silene tomentosa before 1994. Even the scientific community outside Gibraltar was unaware of its status and considered the species extinct (Jeanmonod & Bocquet, 1981, Talavera, 1990). In Gibraltar GONHS botanical section knew it was still around in 1985 (Cortes & Linares 1993, Linares et al. 1996) but by 1992 it was considered probably extinct.

The Gibraltar Botanic Garden set about trying to establish its status in 1992, soon after its creation, relying as ever on GONHS volunteers. In 1994 the plant was rediscovered growing in the wild (Linares 1998, Cortes et al. in prep.). Apart from the conservation significance it presented an ideal opportunity for making advances in the popular standing of the Gardens. Publicity was given to the rediscovery of this "missing, presumed extinct" species immediately, and note was made in particular of the fact that this plant was

  1. one of the rarest in the world,
  2. found nowhere else in the world, and
  3. that cuttings had been sent to Kew for micropropagation.

The psychology of this is clear:

  1. makes the community feel special and important thanks to a plant,
  2. appeals to a nationalistic section of the audience,
  3. associates the Garden with a well-known international institution while introducing to the public a subject, micropropagation, unknown to most of them.

The rediscovery could have gone unheeded, or noted only in learned journals. Instead it was the subject of newspaper articles, radio interviews and television documentaries. (Thanks to an article in National Geographic which referred to Silene tomentosa the plant has appeared in magazines around the world, and on television in Japan). Silene is now a well known plant in Gibraltar.

Taxi drivers, who on their tours long gave (wrongly) the Gibraltar Candytuft Iberis gibraltarica as the unique flower of Gibraltar, now correctly refer to Silene tomentosa and tell the story of its rediscovery and recovery. Silver perfume bottles bearing a reproduction of the flower have been made and sold (in aid of the Botanic Gardens) and a block of flats in a new housing estate has been named Silene House. The botanical influence goes further, as the other two blocks have been named Iberis and Limonium (after Limonium emarginatum, the Gibraltar Sea Lavender, an endemic of the Strait of Gibraltar).

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Keeping Parrots
A botanic garden's responsibilities are not necessarily restricted to plants. In May 1994 a ship called at Gibraltar bound for Europe with an illegal (non-CITES) consignment of African Grey Parrots Psittacus erythacus and chimpanzees Pan troglodytes. These were confiscated by Gibraltar Customs and, as no zoological garden or similar facility existed in Gibraltar, eyes turned to the Botanic gardens, which provided the space for holding facilities. The parrots are still there, together with Timneh Grey Parrots Psittacus erythacus timneh, Senegal parrots Poicephalus senegalus, two sulphur crested cockatoos Cacatua sulphurea, three crab eating macaques Macaca fascicularis and eight pig-tailed macaques Macaca nemestrina, Spur thighed tortoises Testudo graeca and several other species.

While it can be argued that keeping these animals diverts funds from garden upkeep and botanical work (the construction of the cages was funded by the Government of Gibraltar with voluntary labour provided by GONHS), the action served once more to attract attention to the gardens, expand their conservation role, and increase the garden's profile and popularity in the community.

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Urban Landscaping and Trees

"If you can keep a beautiful garden, you can make mine beautiful too". The botanic gardens are a central reference point for enquiries on all aspects of plant care. These range from giving advice on house plants, to having to tell an elderly lady that the geraniums she'd kept in her pots for the past fifty years have succumbed to the newly arrived Geranium Bronze Cacyreus marshalli, and from holding the occasional Saturday morning plant clinics to being called in to design major landcaping projects.

Garden staff have been contracted to design plans for cultivated areas in all Ministry of Defence Estate in Gibraltar (a total of 170 hectares) and a new 2 ha garden area on land reclaimed from the sea. Not only has the opportunity been taken to diversify landscaping in the city, incorporating plants used in the botanic gardens but not so far elsewhere in Gibraltar (a prime example being Pelargonium quercifolium), but the use of native species in these landscapes has been promoted. Thus species incorporated into the plans have included stone pine Pinus pinea, carob Ceratonia siliqua, wild olive Olea europaea, lentisc Pistacia lentiscus, cork oak Quercus suber and nettle tree Celtis australis.

There are not many mature trees in Gibraltar. The main scrub and woodland areas are of recent origin (Cortes 1994a) and housing in particular continues to put pressure even on isolated trees in the odd green patch of ground in built-up areas. Apart from the trees within the botanic gardens (mainly olive, stone pine and dragon tree Dracaena draco) and in a few other gardens on the south west slopes of the Rock (where nettle tree and laurel Laurus nobilis predominate) there are no trees in Gibraltar of more than 200 to 250 years (this coincides with the military sieges of Gibraltar by Spanish forces in the 18th century when continuous bombardment from the sea levelled and burnt most of the City).

The Gibraltar Botanic Garden has therefore adopted, as part of its aims, a policy to minimise the loss of existing trees. This it exercises directly, as it is consulted on every occasion when a request is made to Government to fell a tree, and indirectly, through its association with GONHS (whose representative on the Territory's Development & Planning Commission (DPC) is the Garden's Director) and as the recipient of numerous calls from concerned members of the public when trees are seen to be cut.

All trees on Crown Land are protected under the Town Planning Ordinance (1973), all trees on private land can only be felled with the Governor's permission under the Criminal Offences Ordinance (1960) and in addition all native species except fig Ficis carica, Osyris Osyris quadripartita, Mediterranean buckthorn Rhamnus alaternus and wild olive Olea europaea are protected under the reverse listing system of the Nature Protection Ordinance (1991). Under the procedure set up by the Government, the Botanic Garden has a say in all tree felling and is consulted on pruning, although the final decision is that of the DPC (taken if necessary by majority vote).

A few examples will serve to illustrate how this works:

A. A private individual with a leased property within 30 metres of the perimeter of a nature reserve wishes to exercise his rights under an existing agreement to develop adjacent land and requests a building permit. He claims no trees will be lost. DPC refers this to the gardens/ for a view. A site visit with the Government Environment Ministry's Town Planner determines the new house would cause the demise of four young trees and the vehicle access to the site would result in the removal of a large olive estimated at about 150 years. DPC replies that the building can only go ahead if no trees are lost. The individual amends his plans. He changes the location of the house slightly and re-routes the access drive so that no trees will be lost. The building permit is issued.

B. A private individual wishes to remove a well grown Tree of Heaven Ailanthus altissimus from his patio as he claims it is unsafe and will fall soon. The Town Planner refers this to the Botanic Garden. The tree is inspected and considered safe. Although of a species that is common, it is a fine specimen in an urban setting. Permission for felling is refused.

C. The owner of a hotel in the city centre instructs contractors to commence the removal of a tall Washingtonia robusta from its poolside garden. The contractors erect scaffolding and start to remove leaves. A member of the public sees this and reports it to the Garden. The Garden communicates this to the Town Planner who sends the Building Inspector to the site. Works are stopped, permission, requested by the hotel in retrospect is withheld, but the palm tree dies due to the work already done on it. The hotelier is ordered to fund the planting of three trees elsewhere in Gibraltar and legal action is considered. All this was done in consultation with the botanic garden's management.

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Habitat Restoration

The Great Eastern Sand Slopes of Gibraltar are a landscape feature possibly unique in Europe. They consist of Quarternary windblown sands (Rose & Rosenbaum 1990) and held a vegetation typical of maritime sands which, judging from the floras of the 19th and early 20th centuries (Debeaux & Dautez, 1888; Kelaart, 1846; Wolley-Dod, 1914) and from the vegetation of the remaining peripheral areas, consisted of a Malcolmietalia with characteristic species such as Malcolmia littorea, Pancratium maritimum, Dipcadi serotinum and Cachrys sicula as well as the endemic form Ononis natrix natrix ramossisima.

Between 1907 and 1927 the vast majority of the slopes were covered with corrugated iron sheets to form a massive water catchment area to provide drinking water for the Colony. This resulted in the loss of the majority of this habitat, including the loss from Gibraltar of four species of sandy areas Cortes 1994b). Much of the remaining uncovered sand slope was planted with exotic species including Acacia cyclops, Phoenix canariensis, Agave americana, Aloe arborescens, Opuntia vulgaris and, most regrettably Carpobrotus edulis.

As in so many places, this last species has smothered large areas to the exclusion of many native plants (Cortes 1994c). Following the conversion to sea water desalination as the main source of fresh water, the maintenance of such a large area of corrugated iron, especially with large sections ripped up by wind during storms every few years, became uneconomical. Both the Gibraltar Government and the Ministry of Defence, which administer approximately equal halves of the catchment, decided to remove the sheeting. Initial Government plans included the quarrying of the underlying sand for the building industry, a move opposed by GONHS with the Garden's backing. (Attempts to quarry a part of the slopes which had never been covered by sheeting was stopped when GONHS called in the Police after specimens of Ononis natrix, protected under the Nature Protection Ordinance, had been uprooted without licence.)

A change in political administration resulted in the idea of quarrying being dropped as economically nonviable. Immediately Government was approached by the botanical lobby stressing the importance of avoiding the use of non-native species for stabilisation and pointing out the opportunity for habitat restoration. The arguments were accepted and the gardens were contracted first by the Gibraltar Government and subsequently by the Ministry of Defence to collect seed of native species from the surrounding habitats and to sow the seed in the areas cleared of iron sheets. This work is ongoing, with seed collection progressing and sowing under pvc and coir matting. Thesuccess of the seeding programme first became evident in the spring of 1998 with up to 40% vegetation cover being achieved.

The programme has now progressed from a fairly informal arrangement to one in which the re-establishment of the habitat has become one of the main aims recognised in tender documents and conultation with the Gardens as to admissible seed and shrubs. The progress in re-establishing the vegetation of the sand slope is being monitored (Cortes, Shaw & Linares, in prep.) and the whole project has been given extensive coverage in the local media. Tables 1 lists the species sown on the slopes in autumn/winter 1997/98.

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These case studies provide an example of strategies by which the Gibraltar Botanic Garden has been able to expand its aims outside its boundaries. A summary of the philosophy and actions involved is given in Figure 1. It is always easy to state your aims. It is always possible to claim to campaign by advocating these in discussions and meetings, and even publications.

It is easy to complain about loss of biodiveristy, and even to know what to do about it. It is easy, when you have so much to do, so many priorities to arrange, so little money to handle, to leave it at that. Yet so much can be achieved with just that little more effort, and that little bit more of a fighting spirit. An integral part of a botanic garden's strategy should be to use its resources, however limited, to influence decisions outside. The Gibraltar Botanic Gardens has extremely limited resources. A budget of £240 000 a year is small. And yet its resources have been used to great effect and in just a few years have impacted in the Community and in conservation in its area of influence. Don't just save a species from extinction, or recreate an endangered habitat. Make sure people know about them and get them on your side.

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Posidonia beds (sea grass meadows) Reefs


Vegetated sea cliffs of the Mediterranean coasts (with endemic Limonium spp.)


Malcolmietalia dune grasslands


Matorral with Laurus nobilis


All types


Calcareous sub-types


Caves not open to the public

Submerged or partly submerged sea caves


Olea and Ceratonia forests


Putting your message into effect.

Identify your audience:

  • garden staff
  • the community: who is your community ?
  • your city
  • its schools
  • its clubs
  • Its NGOS


  • who can you influence ?
  • why do you want to ?
  • how do you do it ?
  1. "government" at local/regional/national level. planning authorities developers educators the media
  2. make decisions in favour of conservation regulate development gain allies get them to work for you
  3. be pushy: lobby, lobby, lobby feel what you stand for, preach and practice obtain support of kindred spirits: individuals, NGO, academic insitutions, the public use the media promote your work everywhere obtain representation in decision-making bodies become popular

Table 1: Seeds used in sowing section of the Great Sand Slopes, Gibraltar, following removal of water catchments. autumn/winter 1997/1998.

Allium ampeloprasum
Ammophila arenaria
Antirhinum majus
Cakile maritima
Calicotome villosa
Dactylis glomerata
Daucus carota
Delphinium nanum
Ecballium elaterium
Echium creticum
Eryngium maritumum
Ferula tingitana
Gerenium purpureum
Glaucium flavum
Hirschfeldia incana
Lavatera arborea
Lobularia maritima
Lolium rigidum
Lotus arenarius
Malcolmia littorea
Ononis cossoniana
Ononis natrix
Orlaya maritima
Otanthus maritimus
Paronychia argentea
Piptatheum miliaceum
Plantago coronopus
Rumex Sp.
Scabiosa atropurpurea
Senecio cinerarea
Silene nicaaensis

The Mediterranean Bed in the Gibraltar Botanic Gardens, showing native vegetation in early spring.

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Regenerating vegetation on the Great Sand Slopes, Gibraltar. rock1.jpg: One view of the sea cliffs of Gibraltar.

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Silene tomentosa growing in the Gibraltar botanic gardens (together with Cerastium gibraltaricum and Iberis gibraltarica.

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Copyright 1999 NBI