Vallee de mai nature reserve

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VALLEE DE MAI NATURE RESERVE

SEYCHELLES

The scenically superlative palm forest of the Vallée de Mai is a living museum of a flora that developed

before the evolution of more advanced plant families. It also supports one of the three main areas of

coco-de-mer forest still remaining, a tree which has the largest of all plant seeds. The valley is also the

only place where all six palm species endemic to the Seychelles are found together. The valley’s flora

and fauna is rich with many endemic and several threatened species.

COUNTRY

Seychelles

NAME

Vallée de Mai Nature Reserve

NATURAL WORLD HERITAGE SITE

1983: Inscribed on the World Heritage List under Natural Criteria vii, viii, ix and x.

STATEMENT OF OUTSTANDING UNIVERSAL VALUE

The UNESCO World Heritage Committee issued the following Statement of Outstanding Universal

Value at the time of inscription

Brief Synthesis

Located on the granitic island of Praslin, the Vallée de Mai is a 19.5 ha area of palm forest which remains largely

unchanged since prehistoric times. Dominating the landscape is the world's largest population of endemic coco-de-

mer, a flagship species of global significance as the bearer of the largest seed in the plant kingdom. The forest is

also home to five other endemic palms and many endemic fauna species. The property is a scenically attractive

area with a distinctive natural beauty.

Criterion (vii): The property contains a scenic mature palm forest. The natural formations of the palm forests are of

aesthetic appeal with dappled sunlight and a spectrum of green, red and brown palm fronds. The natural beauty

and near-natural state of the Vallée de Mai are of great interest, even to those visitors who are not fully aware of

the ecological significance of the forest.

Criterion (viii): Shaped by geological and biological processes that took place millions of years ago, the property is

an outstanding example of an earlier and major stage in the evolutionary history of the world's flora. Its ecology is

dominated by endemic palms, and especially by the coco-de-mer, famous for its distinctively large double nut

containing the largest seed in the plant kingdom. The Vallée de Mai constitutes a living laboratory, illustrating of

what other tropical areas would have been before the advent of more advanced plant families.

Criterion (ix): The property represents an outstanding example of biological evolution dominated by endemic

palms. The property's low and intermediate-altitude palm forest is characteristic of the Seychelles and is preserved

as something resembling its primeval state. The forest is dominated by the coco-de-mer

Lodoicea maldivica

but

there are also five other endemic species of palms. Located in the granitic island of Praslin, the Vallée de Mai is the

only area in the Seychelles where all six species occur together and no other island in the Indian Ocean possesses

the combination of features displayed in the property. The ancient palms form a dense forest, along with

Pandanus

screw palms and broadleaf trees, which together constitute an ecosystem where unique ecological processes and

interactions of nutrient cycling, seed dispersal, and pollination occur.

Criterion (x): The Vallée de Mai is the world's stronghold for the endemic coco-de-mer

Lodoicea maldivica

and the

endemic palm species millionaire's salad

Deckenia nobilis

, thief palm

Phoenicophorium borsigianum ,

Seychelles

stilt palm

Verschaffeltia splendida

, latanier millepattes

Nephrosperma vanhoutteanum

and latanier palm

Roscheria

melanochaetes

, are also found within the property. The palm forest is relatively pristine and it provides a refuge for

viable populations of many endemic species, including the black parrot

Coracopsis nigra barklyi

, restricted to

Praslin Island and totally dependent on the Vallée de Mai and surrounding palm forest. Other species supported by

the palm habitat include three endemic species of bronze gecko, endemic blue pigeons, bulbuls, sunbirds,

swiftlets, Seychelles skinks, burrowing skinks, tiger chameleons, day geckos, caecilians, tree frogs, freshwater fish

and many invertebrates.

Integrity

The ecological integrity of the Vallée de Mai is high, but the 19.5ha that constitutes the property's size is relatively

small and its present status is due to some replanting of coco-de-mer undertaken in the past. The property is

embedded within the Praslin National Park (300ha) which provides a sufficiently large area to ensure the natural

functioning of the forest ecosystem. To enhance the property's integrity, the World Heritage Committee has

recommended extending the property to include the rest of the Praslin National Park, thus providing an appropriate

buffer zone.

Protection and Management Requirements

The property is legally protected under national legislation and is managed by a public trust, the Seychelles Islands

Foundation. The management of the property has been enhanced with the adoption of a management plan in

2002. Fire is considered the most significant threat to the property, and fire response and contingency plans are

essential. Tourism, as managed by the public trust, makes a significant financial contribution to the protection and

management of the property. The overexploitation of coco-de-mer can exhaust natural recruitment, and illegal

removal of the seeds is a serious problem that affects future regeneration; thus, a key management priority is to

maintain the palm forest by direct human manipulation with the collection and planting of the seeds before they are

stolen and sold. Effective measures to mitigate threats to endemic fauna and flora from invasive species, pests and

diseases are also essential.

IUCN MANAGEMENT CATEGORY

IV Habitat/Species Management Area

BIOGEOGRAPHICAL PROVINCE

Seychelles & Amirantes Islands (4.16.13)

GEOGRAPHICAL LOCATION

The valley is in the centre of Praslin National Park on Praslin Island, 50km north-east of Mahé in the

Seychelles Islands of the western Indian Ocean at 4°19'S, 55°44'E.

DATES AND HISTORY OF ESTABLISHMENT

I948: The valley was acquired by the government as a part of the catchment area of Praslin Island;

1966: Declared a Nature Reserve under the Wild Birds Protection (Nature Reserves) Regulation

S.I.27;

1978: The Coco-de-mer Management Decree passed;

1979: Praslin National Park designated under the National Parks and Nature Conservancy Act

(Cap.159) S.I.57.

LAND TENURE

Government. Managed by the Seychelles Islands Foundation (SIF).

AREA

19.5ha, within Praslin National Park (342ha).

ALTITUDE

Between ~110m and ~210m.

PHYSICAL FEATURES

The Seychelles is a widely spaced archipelago in the western Indian ocean. The north-easternmost

group consists of 41 islands of rugged preCambrian granite. Praslin Island, in the north of this group, is

the second largest island, 3,756ha in area. The Vallée is in the central hills in the northeast of Praslin

National Park. It is in the lower part of a valley from which two streams flow, the Nouvelle De-Couverte

and Fond B'Offay rivers, flowing west and east respectively, though it does not include all of their

headwater catchments. The site was untouched palm forest until the 1930s when development of a

plantation of exotic trees and the exploitation of coco-de-mer palm seeds began. Drier hills on the edge

of the valley have suffered soil erosion as a result of forest fires and deforestation, so that the soil is

degraded and the forest is secondary growth. However, most of the valley is still in a near natural

condition.

CLIMATE

The climate is humid tropical with annual temperatures varying between 24° and 32°C. Annual rainfall

on Praslin is about 2200mm. There is a drier season during the south-east monsoon from April to

September and a wetter slightly warmer season during the northwest monsoon between October and

March. The island lies north of the cyclone belt and has been relatively free from strong winds (Walsh,

1984) SIF, pers.comm., 1995) though the incidence of major storms is increasing (Lundin & Linden,

1995). For instance a mini-cyclone affected Praslin and nearby islands in September 2002, causing

significant damage (UNEP, 2003).

VEGETATION

The rainforest of the Vallée de Mai is an outstanding example of a stage in the development of the

world's flora before the evolution of more advanced plant families (IUCN, 1983). Three main vegetation

types occur in the site: valley palm forest, intermediate palm forest and secondary forest on eroded

land. The site is too small to be self-sustaining, and several endemic species are maintained only

through human agency. But it does contain all the ecological components needed for the continued

existence of the extremely rich endemic flora: 28 endemic plants, including four screwpines and 14

broadleaf trees.

The palm forest is characterised by the endemic coco-de-mer palm

Lodoicea maldivica

which has the

largest seed in the plant kingdom, weighing up to 18kg, and has been much sought after for that

reason. Its canopy reaches 30m high. All six palm species endemic to the Seychelles occur in the

valley, all belonging to monospecific genera. As well as coco-de-mer there are millionaire’s salad

Deckenia nobilis

(VU), thief palm

Phoenicophorium borsigianum

, Seychelles stilt palm

Verschaffeltia

splendida

, latanier palm

Roscheria melanochaetes

and latanier millepattes

Nephrosperma

vanhoutteana

The intermediate palm forest is intermixed with endemic broadleaved trees such as

Northea hornei

(VU) and

Dillenia ferruginea

(VU) and with endemic screwpines such as

Pandanus hornei

(VU) and

sechellarum

(VU). The endemic sedge

Mapanea floribundum

grows in more open and rocky places,

and a dense growth of the sedge

Scleria sumatrensis

occurs on open, marshy patches on the forest

floor. Areas on the edge of the valley where the soil has been degraded by burning have been

recolonised by endemics such as

Paragenipa wrightii

Pandanus multispicatus

(VU),

Phoenicophorium

borsigianum

Memecyclon eleagni

(VU),

Syzygium wrightii

(VU),

Deckenia nobilis

, and

the vine

Secamone schimperiana,

or by planted indigenous species such as

Calophyllum inophyllum

and

Intsia

bijuga

(VU), and exotic species such as

Tabebuia pallida

, red sandalwood

Adenanthera pavonina

and

coco plum

Chrysobalanus icaco

(SIF, pers. comm., 2006).

FAUNA

The site is a BirdLife International designated Important Bird Area. Its most notable bird is an endemic

subspecies of black parrot

Coracopsis nigra barklyi

, restricted to Praslin Island and dependent on the

Vallée de Mai and the surrounding palm forest.

Leptailurus serval

The population in 2001 was 200-400

birds. Other notable birds include the endemic Seychelles bulbul

Hypsipetes crassirostris

, Seychelles

blue pigeon

Alectroenas pulcherrima

and sunbird

Nectarinia dussumieri

, the re-introduced Seychelles

kestrel

Falco araea

(VU)

and the endemic cave-nesting Seychelles swiftlet

Collocalia elaphra

(VU).

Exotic birds include Indian mynah

Acridotheres tristis

and barn owl

Tyto alba affinis

. The only two

indigenous mammal species are the endemic Seychelles flying fox

Pteropus seychellensis

, which

roosts in the Reserve, and Seychelles sheathtailed bat

Coleura seychellensis

(CR). Also occurring is

the introduced tenrec

Tenrec ecaudatus

from Madagascar.

Reptiles include the endemic tiger chameleon

Calumma tigris

(EN), Seychelles house snake

Lamprophis geometricus

(EN), Seychelles wolf snake

Lycognathophis seychellensis

(EN), the

introduced blind snake

Ramphotyphlops braminus

, endemic Seychelles giant and small day geckos

Phelsuma sundbergi

and

P. astriata

, Seychelles bronze-eyed gecko and skinks

Mabuya sechellensis

Scelotes gardineri

, and

S. braueri

. One endemic the Seychelles tree-frog

Tachycnemis seychellensis

and the introduced Mascarene grass frog

Ptychadena mascareniensis

are known from the area. Six

species of endemic worm-like caecilians are known to occur in the deep beds of moist humus, but are

rarely seen. The stream contains the endemic freshwater crab

Seychellum alluaudi

, giant crayfish

Macrobrachium lar

and shrimps

Caridina

spp. (Bosc, 2004). Two endemic snails which occur are brown

snail

Stylodonta studeriana

(EN) and blackfish snail

Pachnodus praslinus

(VU)

.

There is also a range of

orthopterid insects (SIF, pers. comm., 2006) and a recently discovered fruit fly

Drosophila sechellensis,

associated with coco de mer fruits that have been dehusked (SIF, pers. comm., 2006)

CONSERVATION VALUE

The scenically superlative forest palm forest of the Vallée de Mai is a living museum of a stage in the

evolution of the world's flora before the development of more advanced plant families. It is also the site

of one of the three main populations of coco-de-mer remaining in Seychelles. The coco de mer palm is

notable for its seeds, the largest of all plants’, and for the very large leaves of the juvenile palms. Vallée

de Mai is the only place where all six palm species endemic to the Seychelles are found together. The

valley’s flora and fauna is rich with many endemic and several threatened species. The Park lies within

a Conservation International-designated Conservation Hotspot, a WWF Global 200 Eco-region, a

WWF/IUCN Centre of Plant Diversity and is one of the world’s Important Bird Areas.

CULTURAL HERITAGE

The first record of the islands was on a 9

century Arab chart. The first recorded landfall was in 1609,

after which the islands became a popular port of call for pirate ships. The French claimed the islands in

1754, when bringing slaves from Africa, and named them after their finance minister, and Praslin Island

after the minister for the navy. The British succeeded them in 1815 and many freed slaves were settled

in the country but the culture remained largely French-influenced (Creole). Immigrants from Asian

countries also arrived, many intermarrying with local people and the population reflects this very mixed

background. Much use was made of the coco de mer palm between the 18

and early 20

centuries,

with trunk and leaves being utilised in house building, young nuts used as food and mature nuts

fashioned into containers and household implements.

LOCAL HUMAN POPULATION

There are no inhabitants in Vallée de Mai, although there is a forestry settlement in the National Park

where forest and park rangers live, but the surrounding population of Praslin Island is increasing.

VISITORS AND VISITOR FACILITIES

The Park is popular and well visited. 41 to 48% of all visitors to the country visit Vallée de Mai. Visitors

to Seychelles in 2005 numbered 129,333, with 82% being from Europe (SIF, pers. comm., 2006).

Access is from the main road. There is an information centre and a small shop by the entrance. Access

within the Reserve is restricted to a carefully designed system of marked paths, and guided tours are

available (SIF, pers. comm., 1995).

SCIENTIFIC RESEARCH AND FACILITIES

The palm forests are of great botanical interest. Some work has been done by individual researchers on

the black parrots and on palm geckos. Savage & Ashton studied in 1976 the population structure of all

palm species and calculated a growth rate for

Lodoicea maldivica

. An age table related to the height of

the trees was generated. In 1985 the Expedition from Oxford University established six permanent

sample plots and again analysed the population structure of

Lodoicea

but also looked at the forest

composition. In 1998 the Geobotanical Institute Zürich resurveyed the permanent sample plots and

found that the palm forest was well managed and that invasion by alien species is moderate. Research

in the population structure has continued and it was found that the human impact on the Vallée de Mai

population was underestimated (Fleischer-Dogley & Kendle, 2002). A U.K.University Expedition in 1976

studied forest regeneration, the Seychelles fruit bat, tenrecs and black parrot (Ascroft

et al

., 1976

&1977). Savage & Ashton have studied the population structure of the coco-de-mer palm (1983) and

the impact of tourism (1991). A Science Workshop was held in 2006 to prioritise research needs and

efforts will be made to encourage further research in Vallée de Mai. There are currently no research

facilities on site.

MANAGEMENT

Since January 1989 the management of Vallée de Mai has been entrusted to the Seychelles Islands

Foundation (SIF): this NGO also manages Seychelles’ other World Heritage Site, Aldabra Atoll.

Management policies were originally set by the Seychelles National Environment Commission. A

management plan for Vallée de Mai was prepared in 2002, to serve until 2008. The firebreak around

the Reserve is regularly maintained and alien species are controlled. The Reserve itself is a strictly

protected zone within the surrounding Praslin National Park. The trade in coco-de-mer nuts is

controlled by law. A registration system for selling the nuts seems to facilitate control, together with

enforcement of the Coco de Mer Management Decree of 1994. At present the palm forest must be

maintained by collecting and planting the seeds before they are stolen for sale.

Before 1930 a private owner logged the timber in the valley and introduced many exotics such as

coffee, patchouli

Pogostemon cablin

, cinnamon

Cinnamomum verum

Psidium cattleianum

Paraserianthes falcataria

and

Epipremnum

spp. which the present management for many years has

been replacing with native palms. Expansion of the World Heritage site across the road from the Vallée,

to include an area of high quality forest which has a large population of coco-de-mer, was

recommended by the original IUCN evaluators who also recommended extending World Heritage

status over the whole of the National Park, as a buffer to ensure the continuing integrity of the forest

and to encourage the implementation of the existing management plan (IUCN, 1983). In 2006 the

Seychelles Government approved an extension of the area under SIF management (known as Fond

Peper), although the area still has to be officially surveyed and the lease finalised. SIF is to sign a

Memorandum of Understanding with the Department of Environment to formalise the management of

this extended area.

MANAGEMENT CONSTRAINTS

There are difficulties in effectively patrolling the area, and poaching of coco-de-mer nuts is a serious

problem that affects future regeneration. There is considerable risk of fire, although all smoking or use

of fire is prohibited in the Reserve. As the island is small but increasingly dependent on the growth of

tourism, constant monitoring will continue to be necessary to prevent abuse. Another potential problem

is that the site does not include the whole water catchment area of its streams and the island’s

population and water needs are growing rapidly. Activities of any type on the slopes above the valley

within the National Park could adversely affect the site itself. Threats to endemic birds from rats and

feral cats are being met by specially prepared rat-proof nesting boxes for the black parrots (SIF, pers.

comm., 1995). Well trained and motivated staff are sometimes difficult to retain.

STAFF

A warden, assistant warden, 3-4 rangers and maintenance staff are employed by the Seychelles

Islands Foundation.

BUDGET

The admission charges pay for its upkeep (and for Aldabra Atoll) but are not used for the National Park.

LOCAL ADDRESSES

Chairman, Seychelles Islands Foundation, PO Box 853, Victoria, Seychelles

REFERENCES

The principal source for the above information was the original nomination for World Heritage status.

Ascroft, D.

et al

. (1976).

Aberdeen University Expedition to Praslin Island, Seychelles, Summer 1976

Preliminary Report.

IUCN (1983).

World Heritage Nomination. The Vallée de Mai Nature Reserve

. Technical Review.

Bailey, O. (1971).

List of the Flowering Plants and Ferns of Seychelles with their Vernacular Names

Mahé, Seychelles.

Beaver, K. (2006)

Proceedings of the Vallée de Mai Science Workshop

, Seychelles Island Foundation,

Mahe, Seychelles

Beaver, K. & Chong Seng, L. (1992)

Vallée de Mai.

SPACE, Seychelles

Bosc, P., Keith, P., Valade, P. & Grondin, H. (2004)

Inventaire des espèces de poissons et de

macrocrustacés d’eau douce des principales rivières pérennes des îles de Mahé et de Praslin,

République des Seychelles,

Centre des Eaux Douces

ARDA, La Réunion.

Carlström, A. (1996)

Endemic and Threatened Plant Species on the Granitic Seychelles.

Seychelles

Government report.

Edwards, P., Kollmann, J. & Fleischmann, K. (2003). Life history evolution in

Lodoicea maldivica

(Arecaceae).

Nordic Journal of Botany

22:227-237.

Evans, P. & Evans,J.(1980) The ecology of lizards on Praslin Island, Seychelles.

J. Zool. London

191:171-192

Fleischer-Dogley, F. & Kendle.T. (2002). The conservation status of the coco de mer

Lodoicea

maldivica

(Gmelin Persoon): a flagship species. pp 369-382. In

Maunder, M., Clubbe, C., Hankamer, C.

& Groves, M. (eds).

Plant Conservation in the Tropics. Perspectives and Practice

. R.B.G., Kew, UK.

Fleischmann, K. (1998)

Vallée de Mai,

Geobotanical Institute at the Federal Institute of Technology,

Zürich, Switzerland

Fleischmann, K.,Edwards, P. Héritier, P. Meuwly, C. & Kueffer, C. (2003). Virtual gallery of the

vegetation and flora of the Seychelles.

Bull. Geobotanical Institute

ETH 69:57-64.

Friedmann, F. (1986)

Fleurs et Arbres des Seychelles.

ORSTOM + Min. of Finance, Seychelles

---------- (1994)

Flore des Seychelles – Dicotylédones.

ORSTOM, Paris

Gadow, H. & Gardiner, S. Aves with some notes on the distribution of the land birds of the Seychelles.

Trans. Linn. Soc. Land. Zool.

2.12: 103-110.

Gardner, A. (1986). The biogeography of the lizards of the Seychelles Islands.

J. Biogeog

. 13: 237-253.

Héritier, P. (2002).

Ecological Value of the Fond Ferdinand, Praslin, Seychelles and Possible

Connection Between Fond Ferdinand and Vallée de Mai.

Diploma thesis. Geobotanical Institute, ETH

Zurich, Zurich, Switzerland.

High, J. (n.d.).

The Natural History of the Seychelles

. Seychelles Nature Handbook.

Hilton-Taylor, C. (complier)(2004).

IUCN Redlist of Threatened Species.

IUCN, Gland/Cambridge, U.K.

Kendle, T.

et al.

(2002)

Vallée de Mai Management Plan 2002-2008.

Seychelles Islands Foundation.

Lundin, C. & Linden, O. (eds) (1995).

Integrated Coastal Zone Management in the Seychelles.

Ministry

of Foreign Affairs, Planning & Environment, Mahé/SIDA/ World Bank.

Meuwly, C. (2002)

Fire and Vegetation on Praslin and in the Fond Ferdinand,

Geobotanical Institute,

ETH Zurich, Switzerland.

National Statistics Bureau (2005)

Statistical Abstract 2004,

Victoria, Seychelles

Nussbaum, R. (1984). Amphibians of the Seychelles. In Stoddart, D. (ed.) (1984).

Biogeography and

Ecology of the Seychelles

. Junk, The Hague, Netherlands.

Oxford University Biological Expedition to the Seychelles (1985),

Scientific supplement,

Seychelles

Archives F/4 474: 24-43, Seychelles

Reinhardt, A. & Voellmy, M. (2000)

Zonation of the vegetation of Praslin National Park,

Geobotanical

Institute at the Swiss Federal Institute of Technology, Zürich, Switzerland

Savage, A. & Ashton, P. (1983). The population structure of the double coconut and some other

Seychelles palms.

Biotropica

15(1): 15-25.

Savage, A. & Ashton, P. (1991). Tourism is affecting the stand structure of the coco-de-mer.

Principes

35(1): 47-48.

Silvertown, J. (1987)

Possible sexual dimorphism in the double coconut – reinterpretation of the data of

Savage and Ashton

, Biotropica 19: 282-283

Stoddart, D. (ed.) (1984).

Biogeography and Ecology of the Seychelles

. Junk, The Hague, Netherlands.

Uhl, N. & Dransfield J. (1987)

Genera Palmarum – A Classification of Palms Based on the Work of

Harold E. Moore, Jr,

Lawrence, Kansas, USA

Vesey-Fitzgerald, D. (1940). On the vegetation of the Seychelles.

J. Ecol

. 28: 465-483.

Walsh, R.. (1984) Climate of the Seychelles. In Stoddart, D.R.(ed.)

Biogeography and Ecology of the

Seychelles Islands

: Junk, The Hague, Netherlands. p. 39-62

Willis, D. (1984). The wild sanctuaries of the Seychelles.

Swara

7(4): 24-27.

Wilson, R. (1980).

The Praslin National Park, A Draft Management Plan

DATE

June 1983. Updated 5-1990, 1-1992, 1-2005, 11-2006, May 2011.