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KARST ECOSYSTEM

2002-07-10KDL 2445

Part?III?? ????Contributions

?

KARST ECOSYSTEM

1

Pot Culture:A Typical Farm Management System on the Degraded Karstland Area, in the Special Province of Yogyakarta,Indonesia

Sambudhi SUdibyo
Department of Soil Science of Agriculture,Gadjah Mada University,
Sekip,Unit I,Yogyakarta, 55182 Indonesia.
Tel:62-0274-548814;Fax:62-0274-563062;?E-mail:soil@ugm.ac.id

Abstract

The region along the southern peripheries of Java island is overlain by a hilly to mountainous karst formation Stretching out from the western to eastern tips of the island.Under the prevailing climatic conditions marked with seasonal extremes of water and heat,the fragility of the erosion prone karst ecosystem has transformed the terrain into a rocky barren landscape that almost devoid of soil and vegetation. The vicious sequence of the deteriorating events is triggered and further intensified by human activities including population pressure,bad landuse planning,and over exploitation of its??natural resources.

The remaining soils on the karstland are mostly confined in rocky or stony holes distributed in a patchy pattern between rock outcrops or boulders of stones.For many of the local peasants these soils are their only resource of living, although a good few of them have odd off-farm jobs.With their inherited skills for subsistence, the peasants cultivate their soils like growing plants in pots.

By pure economic standards,such area is considered having no potential for??development.Some planners with the administration tend to see the peasantries as relicts of a bygone community.?Consequently they are by-passed by the main stream of funds, technical assistance, development facilities,and information. The people are left themselves to survive.Thus,the expression?peasant on the rocks?has been in use both literally as well as figuratively.

The most??obvious solution to the problem is moving the people out from their present homeland and resettling them in other areas outside Java.But the execution maybe strongly constrained by the fact that the displacement will involve tens of thousands of households.The constrains become even more pronounced at present as the Ministry of Transmigration which has thus far been responsible for undertaking the tasks has been liquidated as the results of reformation movements with the government. Another appoach which may mitigate the problems of peasantries should, therefore, be sought within the subsistence farming of their own, by directing it more towards the combined measures for ecological rehabilitation of the area. Driving people to move to this direction is a big and long time-tking task, but necessary. Cooperative movements will be the key to the success of the transformation.

2

Ecological Problems in the Subtropical Karst?of South China

Yuan Daoxian
The institute of Karst Geology,?Guilin, Guangxi, 541004
E-mail:dxyuan@mailbox.gxnu.edu.cn

Abstract

An overview of world karst indicates that most karst environmental problems. especially rock desertification ,occur mainly in tropical and subtropical karst terrains. Population presseure and some malpractices in land use have intensified the processes of rock desertification .In Guizhou Province, the rate of rock desertification in karst areas was as high as 933km2?per year in the 1980s, although in recent years, many projects to deal with this fragile environment in south China have been implemented. Measures such as harnessing underground streams, ecological rehabilitation, and comprehensive development in the poorest karst regions of south China have proved to be successful. However, ecological conditions there vary from place to place as a result of geological, climatic, and topographic differences. Consequently, more research and improved management are necessary for better planning and more effective implementation of rehabilitation measures.

3

Deforestation and Afforestation in Poland, a Historical Review

Andrzej Czylok
Department of Geography, University of Silesia
Bidzinska 60, 41-200 Sosnowiec Poland

Abstract

Deforestation in Poland refers to Polish Jura and the neighbouring sandy area which were subject to such a process 500 years ago. But we are able to find the whole tracts of bare sandy land where the process of natural regeneration is very slow (e.g. The Blendow Desert ) even now. Deforestation was cased by the demand for supplies of wood used as: charcoal by smelt of metals or building material in construction of coalmines, settlements for coalminers and other people involved or as wood-firing. Besides, increasing demand of food supplies resulted in ascending deforestation due to transformation of the land for agricultural needs of new settlers.

On the contrary, the time when the forest regeneration started was about 1950. Black coal was used: in smelting metals, in production of new building materials such as cement, bricks or production of electric energy. So, the area which was described as “the sea of sand” (1811 by Staszic) came back to natural state of forestry-agricultural or forestry landscapes. Generally, the usage of energy stored in coal appeared to be the factor which relieved forests from exploitation. Carrying out the analysis of energy flow through ecosystem (which human being is one of the elements) we could point out the ways exemption forests from their traditional roles as the source of energy and building materials. Moreover, the introduction of some plant species processing the sunny energy could limit the demand for land providing that population of people is stable. In Poland, such a plant is potatoes .

Forestage of Poland has increased about 10% for last 50 years. However, the process seems to speed up for the last 10 years due to the enormous influx of subsided food imported from Europe country to Poland what causes that the home agricultural production becomes less and less profitable. Thus, we have more and more areas which are excluded from agricultural use and spontaneously or trees are planted, increasing the area of forests in Poland

4

Reform of Carbonate Rock Subsurface by Crustose Lichens and Its Environmental Significance

Cao Jianhua and Wang Fuxing
Institute of Karst Geology, Chinese Academy of Geological Sciences,
Guilin ,Guangxi??541004

Abstract????Crustose lichens are distributed extensively in karst areas in Southern China. They can be found on the surface of carbonate rocks. Through biophysical and biochemical processes, crustose lichens reform the subsurface of carbonate rocks and in the meanwhile change their physical and chemical properties: (1) the mechanical strength decreases by 17.04oon average ( up to 33.2o); (2) the chemical solution surface area increase from 28.26% to 75.36%( lichens microholes??considered only); and(3)the water-holding capacity is greatly improved . Comparative field experiments between biokarst samples underneath crustose lichens and fresh rock samples with the same composition and texture show that the corrosional rate of carbonate rocks of the former is 1.264-1.643 times higher than that of the latter. Crustose lichens are considered as an activator of the corrosion of carbonate rocks.

Key words???crustose lichens, carbonate rock, biokarst, corrosion, environmental significance

5

Atmospheric CO2?Dynamics in the Guilin Karst Depression Ecosystem And Environmental Significance

Cao Jianhua1,??Pan Genxing2,??Yuan Daoxian1
(1?Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin, 541004)
(2?College of Environment and Resource ,Nanjing Agriculture University , Nanjing, 210095)

Abstract???The diurnal observation on atmospheric CO2?dynamics in Guilin karst depression ecosystem indicate the following: the karst depression has a certain regulation effect on atmospherical CO2?and may accelerate karst development; the photosynthesis –respiration of bush vegetation is the direct factor for controlling the atmospherical CO2?dynamics in the karst depression ecosystem, while the CO2?emitting from soil, is less important CO2?is both the important driving force of the karst process and the focus of the global change research. The key factor for carbonate rock dissolution and uptaking atmospheric CO2?is the dynamics of CO2and water and their actions near the surface. The results of this research will be conductive to clarifying the mechanism of carbonate rock dissolution and uptaking atmospheric CO2?in terms of dynamic change and provide a new clue for the karst dynamic systm and world carbon cycle study.

Key word:?karst depression , CO2?dynamics, karst process, ecosystem, Guilin

6

Anthropogenic Karst in East Siberia, Russia

Yuri B Trzhtsinsky?
Institute of the Earth’s Crust, Russian Acad. Sci., Siberian Branch
128 Lermontov Street, 664033 Irkutsk, Russia

Abstact

The investigation of karst (both gypsum and carbonate) in East Siberia, Russia is of a great importance, especially the anthropogenic karst, because the man-made water reservoir in Bratsk (on the Angara-river) has caused the sharp activization of karst processes.

7

An Initial Study on Microorganism Diversity in Southwestern?Karst Woods of China?
――Case from Huoshaoping, Changyang, Hubei

??Yu Longjiang

Abstract:?After picking samples of soil in six selected areas of the Karst woods at Yongjiaao of Huoshaoping in Hubei, we studied and analysed the distribution, composition and dominant microorganism as well as microorganism diversity by adopting the taxonomic, ecological and mathematical statistics methods. The correlation of microorganism diversity with vegetation has also been explored.

Key words:?microorganism diversity, dominant microorganism, Karst woods

8

A Preliminary Discussion on the Sustainable Development of Agricultural?
in Fragile Karst Environment of Southwest of China?
――taking Guizhou Province as an example

Su Weichi???Zhou Qingzhen
(Institute of Mountain Resources, Guizhou Academy of Sciences, Guiyang, 550001)

Abstract:?Karst landforms are widely distributed in southwest of China where the eco-environment is very fragile and there are a series of serious problems existing in agricultural sustainable development (ASD). This paper taking Guizhou Province as an example, states its importance to carry out the strategy of ASD for Guizhou karst region, it also explores the target and connotations of ASD, and draws up the map of Eco-environmental fragile types in Guizhou karst mountainous region and points out that it is the basis for ASD of Guizhou Province to protect, improve and restore karst Eco-environment. Finally, the authors propose industrial models and strategy of ASD which are suited to regional features of fragile karst environment of Guizhou Province.

Key words:?Sustainable development of agriculture; Fragile karst environment of Southwest China; Guizhou Province

9

Characteristics of the Karst Ecosystem of Vietnam and?
Their Vulnerability to Human Impact

Do Tuyet
Research Institute of Geology and Mineral Resources (RIGMR)
Add. Thanh Xuan, Ha Noi, Vietnam

Abstract

Karst in Vietnam covers an area of about 60,000 km2, i.e. 18 % of the surface of the country. Annual average temperature is 240C, annual average rainfall is 2300 mm and relative humidity is about 90%. Karst in Vietnam is typical feature of peak-cluster depression landscapes ranging in elevation from 200 m to over 2000 m. Tower and coastal karst landscapes do also exist. Because of naturally favourable conditions, karst ecosystems are diverse and very rich. Higher plants (Cormobiota) are abundant. They are represented by approximately 2000 species, from 908 genera, 224 families, 86 orders and 7 phyla. They form a thick vegetation cover of evergreen tropical rainforest. Knowledge about lower plants is limited. Fauna is rich and diverse. Phyla such as Protozoa, Worms, Mollusca and Arthopoda are yet ill-known. Preliminary results show that the Chordata Phylum is represented by 541 species from 80 families, 40 orders and 5 classes. Many precious and rare mammals exist, in particular some endemic species such as?Trachypithecus poliocephalus, T. delacouri, Rhinopithecus avanculus, Rhinolophus rouxi, Seotoma dineties, Silurus cucphuongensis. The insects class has about 2000 species.

Fast population growth, particularly in the mountainous areas of the country, triggers an increasing demand for land and therefore threatens the ecosystem. To obtain land for farming, people have cut, burned and destroyed natural forest cover, resulting in hazards such as soil-loss, water-loss, flash floods, mud-rock flows, rock-fall, severe drought, water logging, changes of karstic aquifer etc. Poaching precious animals and illegal logging is increasing. In contrast to other natural systems, karst ecosystems cannot be reestablished once damaged. Living karst landscapes will become rocky desert landscape without life. Conservation of the karstic environmental system in general and karstic ecosystem in particular should not be the sole vocation of scientists but also a duty and responsibility of authorities and people from all levels. A good example of a multidisciplinary approach to solve karst-related problems is the implementation of the Vietnamese – Belgian Karst Project (VIBEKAP): “Rural development in the mountain karst area of NW Vietnam by sustainable water and land management and social learning: its conditions and facilitation”. The aim of this project is to improve living conditions of local people and sustained protection and management of??the karst environment and ecosystem.

I.??????physical setting

Karstic areas of Vietnam form part of the tropical karst belt of the earth. They closely relate to the South China tropical – subtropical karst and humid tropical karst of the Indochina peninsular and South - East Asian countries.

Karst in Vietnam covers about 60,000 km2?accounting for 18% of the total area of the country. It consists of 4 regions namely the Northern (Vietbac), North – Eastern, North – Western and North Central Vietnam karsts. The North – Eastern karst region is considered as a karst of both continental and marine origins and is composed of a lot of islands of the famous Halong bay and plenty of tower karst blocks lying near seashore. On the sea bottom many living corals exist. Karst elevation ranges from sea level to over 1,000 m in Vietbac, Phong Nha – Ke Bang and to 2,000 m in the North – Western region. Vietnam’s karst is composed of tower landscapes with towers, monadnocks varying from some tens of meters to over hundreds of meters in diameter and some hundreds of meters to over thousand of meters in height. Peak cluster – depression landscapes with deep dolines, closed valleys are also developed on the continent. They are often seen at favourable geological structure of distribution of thick and homogenous limestone layers. Other landscapes consisting of plenty of dolines and valleys on the valley slopes prolonging some ten kilometers along fault zones are also seen. This karst feature directly controls distribution of flora, fauna, vegetation cover and ecosystem in general. Cave systems are large in dimension and complex in structure with a lot of galleries and rich in water. They are considered as favourable habitats for“underground wildlife”. Climate and soil factors are favourable for the development of flora. Average temperature sum is 8640?0C/ year (corresponding 240C/ day). There are 4 seasons in a year.??Winter lasts from Nov., Dec. to Feb. the folowing year and has an average temperature of 170C, absolute minimum temperature of 1-20C. In summer, average temperature is 27 – 280C and absolute maximum temperature 400C. Total sunny time is 1700 h per year. Total average rainfall is 2100 mm/ year and varies from 1445 mm/ year in Son La, 1923 mm/ year at Cuc Phuong, 2185 mm/ year at Dong Hoi and 2759 mm/ year at Sapa. Average relative humidity is often high (about 87%) and increases in small rain time and with overcast. On surface karst soil is often exposed. The above mentioned conditions are considered to be favourable for the development of flora and fauna. A rich karst ecosystem with high biodiversity is formed.

Recently, several surveys and studys of flora and fauna in the karst regions of Vietnam, particularly in conservation areas and national parks such as Cuc Phuong, Pu Luong, Cat Ba, have been carried out. However, a full inventory of karst flora and fauna is not completed yet. This short article describes the characteristics of Vietnam’s karst ecosystem that is typical for tropical humid karst. As regard to its richness and high biodiversity, after estimation of the New York Botanic Park and World Wildlife Fund (WWF):?only Cuc Phuong – Pu Luong is?“A Global Center for Plant Biodiversity”?(Olivier Maxwell, 2000).

II karst ecological system

II. 1. Flora

Surveys and investigations in the Cuc Phuong – Pu Luong area (SE part of NW karst region) up to the year 2000 have revealed 1944 species from 908 genera, 224 families, 86 orders, 15 classes, 7 phyla of?Cormobiota?(table 1).

Table 1.Number of known species of?Cormobiota?in Cuc Phuong – Pu Luong karst area

(after Le Vu Khoi, 1994; Vo Quy et al, 1996).

Phyllum

Class

Order

Family

Genus

Species

Bryophyta

3

9

31

75

127

Psilotophyta

1

1

1

1

1

Lycopodiophyta

2

2

2

2

9

Equisetophyta

1

1

1

1

1

Polypodiophyta

3

7

27

55

129

Pinophyta

3

3

3

3

3

Spermatophyta

2

63

159

771

1674

Total

15

86

224

908

1944

It corresponds to 24.6 %, 43.6 %, and 68.9 % of the total species, families and orders of the whole country respectively (Vo Quy et al, 1996). Some species such as?Pistachia cucphuongensis, Melastoma trungii, Heritiera cucphuongensis, Brassaiopsis cucphuongensis, Scheffera glubalifera, Castanopsis symetricapalata, Alysicarpus vaginalis?have been firstly revealed and are endemic to Vietnam.?Brassaiopsis cucphuongensis?is not only an endemic but also a new species for the world and at the same time represents a new genus of Indochina (Vo Quy et al, 1996).

Many representatives from plant families of?Fagaceae, Fabaceae, Ebenaceae, Annonaceae, Anacardiaceae, Sapindaceae, Sterculiaceae, Melianceae?etc exist since the Tertiary period. Some species such as?Cinnamomum balancae, Caryodaphnopsis tonkinensis, Celtis sinensis, Liquidamba formosana, Saraca dives, Amoara gigantean?have been found in a fossil form in Neogene sediments of the Dong Giao basin. They still exist in the Cuc Phuong forest. The above-mentioned points illustrate old and primary features and high endemism of the studied flora.

Besides, many representatives of different biozones are encounterd in the flora. Among them, species such as?Parashorea chinensis, Vatica subglabra?are representatives of the Indonesian – Malaysian humid tropical biozone. A lot of species from families of?Fagaceae, Aceraceae, Oleaceae, Ulmaceae, Hippocastanaceae?and some species such as?Paris polyphilla, Platycarya strobilacae?are representatives of the Yunanese- Hymalayan temperate biozone. Species such as?Terminalia myriocarpa, Anoycisus tonkinensis?and some species from families of?Combretaceae, Lythraceae, Bombaceae, Sapindaceae?are presentatives of the Indian – Burmese dry biozone (Vo Quy et al, 1996). The abundance and biodiversity of the studied flora is a result of the convergence of the indigenous plants and plants of the migration flows from North-Northwest (Yunanese - Hymalayan) with characteristics of the temperate zone; the West (Indian - Burmese) with dry climate and the South (Indonesian - Malaysian) with a hot humid climate.

Plant density of the studied area is reported to be fairly high, particularly at the bottoms of the closed sinkholes, dolines and valleys. After Le Vu Khoi (1994) there are more than 200 species with biomass of above 1000 m3?per hectare. The flora with its abundance, biodiversity and high density forms a vegetation cover of an evergreen tropical rainforest. Vo Quy et al (1996) distinguished 3 different forest types:

1. The forest type on valley and doline bottoms structured with 5 canopy layers.

+?The emergent canopy layer?consists of trees of some meters to 5 – 6 meter in diameter and 40 – 60 m height. They are scatteredly distributed in the region. Some species such as?Parashorea chinensis, Aglaia gigantea, Annemocarya chinensis, Cinamomum balancae, Terminalia myriocarpa, Tetrameles nudifora, Tetrameles nudifora... are often seen.

+?The ecologically dominant canopy layer?consists of mainly woody trees of 20 – 35m??height, they are regularly distributed and form the main forest canopy. They are composed of species such as?Caryodaphnopsis tonkinensis, Cinamomum sp., Pomeria pinata...

+?The sub-canopy layer?consists of woody trees of 10 – 20 m height and are irregularly distributed; common species are?Gironniera subequalis, Acer decandrum, Saraca dives, Litsea amara, Horfieldia prainii, Endospernum chinensis...

+?The shrub layer?consists of small trees of less than 10 m height composed of many representatives of families of?Annonaceaea, Theaceae, Urticaceae.

+?The forest floor layer?contains a complex community of representatives from?Bryophyta?to?Spermatophyta.

2. The forest type on the slopes structured with 3 canopy layers:

+?The emergent canopy layer?consists of woody trees of 15 – 30 m height such as?Heritiera macrophylla, Pterospermun sp., Chukrasia tabularis, Paviesia annamensis, Diospyros mun...

+?The main canopy layer?includes woody trees of 10 – 15 m height such as?Dimerocarpus brenieri, Teonogia tonkinensis, Arenga pinata, Cayota bacsonensis?and some species from families of?Annonaceae, Enbenaceae.

+?The lower canopy layer?consists of small woody trees, shrubs and grasses with representatives from families of?Acanthaceae, Urticaceae, Rubiaceae?and species?Laportea?sp.

3. The mountain top forest structured with 2 canopy layers:

+?The higher layer?consists of small and short woody trees and shrubs such as?Illicium griffithii, Quercus sp., Scheffela pes-avis, Dracaena cambodiana, Pleomele cochimchinensis.

+?The lower layer?consists of representatives from families of?Bambusoideae, Orchidaceae, Urticaceae.

Besides the 3 main above-mentioned forest types, Olivier Maxwell (2000) distinguished some forest types characterized by human impact:

+ The mixed secondary broadleaf – bamboo forest

+ The secondary bamboo forest

+ The planted bamboo forest

+ The reclaimed land with bushes and scattered trees

Besides high density, large biomass and structure of many canopy layers, Vietnam’s karst forest has typical ecological features of the tropical rainforest such as evergreen leaves and high presence of woody climbers. The latter consist of 20 species from 10 families with representatives such as?Entada tonkinensis. The epiphytes are numerous with species of?Ochidaceae?and?ferns; strangulation epiphytes with specially great development of species of?Loranthaceae; phenomenon of buttress of roots with many tree with buttress roots of 8 – 10 m high and expanding a distance of 10 – 15 m in the surrounding areas, the big and old?Dracontomelum dupperreanum?and?Tetramebs nudiflora?are good examples.

II. 2. Fauna

So far a full inventory of the fauna of Vietnam’s karst biozone has not been completed. Even for Cuc Phuong National park and Pu Luong conservation area, surveys only focused on the?Chordata??phylum, the other phyla remaining ill-studied. Based on available data, the?Chordata?consist of 541 species from 5 classes (table 2).

Mammals?have 88 species of mammals are recorded, representing 30 % of the total mammal species known in Vietnam. Among them Primates are abundant with typical representatives as?Hylobates concolor, H. leucogenys leucogenys, Macaca mulata, M. arctoides, M. assamensis, M. leonina, Nomascus leucogenys, N. concolor, Nycticebus pygmaeas, N. coucany, Trachypithecus phayrei, T. cristalus,?etc.?Trachypithecus delacouri, T. poliocephalus, Rhinopithecus avunculus?are endemic to Vietnam.

Table 2. Species of?Chordata?known in the Cuc Phuong – Pu Luong area karst area

(Vo Quy et al, 1996; Olivier Maxwell, 2000).

Class

Number of species

Mammals

88

Birds

319

Reptiles

39

Amphibia

35

Fish

60

Total

541

Cats and bears have representatives as?Neofelis nebulosa, Felis temmick, Pathera pardus, P. tigris, Ursus thibetunus.?Asian tiger is reported to be extinct in the Cuc Phuong Park but some individuals are present in the Pu Luong Nature reserve (Olivier Maxewell, 2000). Ungulates have representatives as?Cervus unicolor, C. nippon, Naemorphedus sumatraensis, Muntiacus mutjak?and wild pigs. There are some common animals like wild dog, civet, squirel of which?Petaurista petaurista?and?Belomys pearsoni?are two species of flying squirrels: Red-breasted squirrel -?Callosciurus erythracus cucphuongensis?is endemic to Vietnam, Laos and South China. Bats are abundant with 38 species of which?Rhinolophus rouxi, Seotomanes dineties?are endemic to Vietnam.

Birds?are abundant and diverse with 319 species corresponding to 39.8% (of total 800 species known in Vietnam), including water birds living near rivers, stream, lakes and reservoirs of the park’s buffer zones. They have colours from brown as?Passer montanus, Lonchura striata, L. punctulata?to multi-coloured?such as Pericroconus flameus, Alcedo atthis, Halcyon smyrnensis?and barbets, woodpeckers. There are many kinds of birds with beautifully melodious songs such as?Garrulax canorus, G. chinensis, Lanlus sehach. Some birds are rare and precious such as?Pavo multicus, Polyplectron bicalcaratum, Lophura nycthemara, Buceros bicornis, Anthracoceros malabarius.

Reptiles and Amphibians,?according to Olivier Maxwell (2000) 39 reptile species and 35 amphibian species have been reported in the studied area. This inventory is certainly incomplete. Among them there are some poisonous species such as?Naja hannah , N. naja, Bunganus fasciatus, B. candidus, Thimeresurus mucroaquanratus. There are 13 lizard species and 3 turtle species and there is Draco sp. also.

Fish, about 60 fish species including those living in underground – river caves are reported. 5 species discovered in the caves are?Lurus asotus (L.) f. cavernicoles, Lurus conchinchinensis, Silurus cucphuongensis, S. wynaadensis, Liobagrus nignicauda?(Mai Dinh Yen, 1993), in which?Silurus cucphuongensis?is endemic.

Molluscs?are poorly - studied. The abundance and diversity of these animals however is certainly similar to that of the plants of the studied area (Fauna and Flora International Indochina Programme, 2000). In consequence of that, in a short survey of 4 days on snails in Cuc Phuong 90 species were revailed on a trail of 200 m, which is said to be “an absolute record in SE Asia” (after Olivier Maxwell, 2000).

Insects?are abundant in Cuc Phuong – Pu Luong karst area, particularly butterflies. About 1,800 species from 200 families, 30 orders are encountered. In early summer, from the ways through the forest one can see plenty of butterflies flying. They are dancing and jostling each other to make a panchromatic picture of capricious butterflies’ wings or the colourful carpets covering all the paths or on beds of dry springs.

III. vulnerability of Karst ecosystem?to?human impact

In the past decades, population growth (about 1.7 %/ year) and fast economic development, in a backward and agriculturally based country with over 80 % of population living in rural and mountainous areas, have created a high pressure to Vietnam’s ecological environment in general and karst ecosystems in particular. In mountains, especially karst mountains, people continue farming on high slopes and bottoms of closed depressions, dolines, valleys. Fast population growth will require cultivation land. Consequently people cut and fire forest, and so, natural forest gradually moves up to the top areas. According to the Ministry of Forestry (1995), Vietnam’s forest cover has seriously reduced due to multiple?reasons.?In 1943 forest covered 14.3 million hectares (43% of total country’s area). In 1993 this figure was reduced to 9.3 million hectares corresponding to only 28 % territory of the country.

With that tendency, the forest on the karst areas step by step is restricted and the karst ecosystem is gradually damaged. Because the karst environment is fragile and very sensitive to human impact, it is impossible to be restored once destroyed. Consequences are geological hazards such as soil loss (note that soils are very difficult to form on the karst areas), serious drought, flash floods, disturbance of the water balance, destruction of the karst aquifer etc will be occurred. Rock desertification is an inevitable result, the karst ecosystem which is inherently fertile, abundant and alive will be lost and replaced by melancholies, seriousness and life would be disappearing.

Secondly market economy makes people plunging into profits regardless of law and consequence. A lot of small groups of people living not only in the Natural Park and Conservation Forest areas’ buffer zones, but also in the plains go to the forest for profit seeking. To earn money they illegally exploit different woody trees for houses, construction, furniture production and medicinal purposes.

Once the natural forest is damaged its fauna is also lost. Besides, the poaching with fire methods is crudely performed, making the natural reserves with mammals and birds quickly lost. Only in Cuc Phuong Natural Park there are at least 5 species including Asian tiger?(Pathera tigris),?White cheeked Gibbon, Sika Deer, Sambar Deer and Peacock?(Pavo muticus)?that became extinct in the last decades. Flora and Fauna International (FFI) alarms that a lot of species such as?Trachypithecus delacouri, T. poliocephalus, T. cristalus, T. francoisi, T. phayrei, Rhinopithecus avunculus, Black langur, Pygathrix nemaeus, Macaca assamensis, M. mulata, M. fascicularis, M. arctoides, Nycticebus pymaceus, N. coucang, Nomascus leucogenys, N. concolor, Neofelis nebulosa, Catopuma temminek, Pathera tigris, Urus thibetamus, Muntiacus mutjak,?Wild pig animals, Aquila heliaca, Arborophila charltonii, Picus rabieni, Jabouilleia danjoni, Chrotogale owstoni, Callosciurus erythraeus cucphuongensis, Pavo muticus...?are endangered or critically endangered and listed in Vietnam’s Red Data Book.

In order to protect the karst environment and ecosystem from damage and geological hazards, the State and Local Authorities should urgently implement serious policies and regulations for environmental protection and sustainable development. To contribute to protect the environment and karst ecosystem we have collaborated with Belgian researchers to set up a project entitled “Rural development on the karst mountain areas of NW Vietnam by sustainable water and land management and social learning: its conditions and facilitations”. This is a multidisciplinary project, a combination between geosciences and human sciences, with overall aims of environment protection and sustainable development and improvement of living conditions for local people in the karst areas. Its fruitful success is flowered not only by dedications from geo-and-social scientists but also, and more important, is the active participation and support from authorities and local people.

?

References

Fauna and Flora International, Indochina Programme, 2000.??Project document: Conservation of the Pu Luong – Cuc Phuong limestone landscape,?Vietnam. Hanoi, 127.

Le Vu Khoi, 1994.??Studies for setting up the buffer villages for the Cuc Phuong National Park. National Information and Documentation Center. Hanoi, 135.

Ministry of Forestry, 1995.?Vietnam Forestry.?Agricultural publishing house. Hanoi, 70.

Olivier Maxwell, 2000. Current knowledge and state of wildlife in the Pu Luong – Cuc Phuong limestone range.?In project proposal: “Conservation of the Pu Luong – Cuc Phuong limestone range, Vietnam. Fauna & Flora International, Indochina Programme”,Hanoi, 95- 101.

Vo Quy, Nguyen Ba Thu, Ha Dinh Duc, Le Van Tac, 1996.?The Cuc Phuong National Park.?Agriculture Publishing House. Hanoi, 58.

Mai Dinh Yen, 1993. Some freshwater fish species inhabiting the streams and caves of underground water in the karst region of Vietnam.?Studying works on tropical karst of Vietnam, International Workshop, Hanoi, 1993,?Hanoi University, p. 95.