Traditional knowledge , perceptions and forest conditions in a Dayak Mentebah community , West Kalimantan , Indonesia

This study aims to introduce the natural resource uses of Dayak Mentebah people of the village Nanga Dua, West Kalimantan. It is part of the project CoLUPSIA that focuses on reinforcing small stakeholder's rights. Furthermore, ecological data are collected to support the protection of Indonesia's species rich and vulnerable tropical forests, threatened through high deforestation rates. The local people's perceptions about their environment and land uses were assessed using participatory survey techniques: focus group discussions, scoring exercises, free lists of species and participatory mapping. To further record the traditional practices a survey was conducted on medicinal plants. The ecological assessment was done through survey plots in different land use units, where tree diversity and diameter at breast height was measured. The inhabitants of Nanga Dua are dependent upon forest products for food, material for construction, basketry, etc. Medicinal plants are integral part of the health-care system. The traditional, shifting cultivation creates a diverse and mosaic-like patchwork of various types of forests, having different successional stages. Tree diversity in the land-use units was generally high, with the primary forest in immediate proximity acting as tree species reservoir.


List of abbreviations
I am grateful to all the inhabitants of Nanga Dua Village for their hospitality, interest in and support for me and for my work.I admire their courage and knowledge.I will not forget their teachings.Special thanks must go to my host family: Ibu1 Maria, Bapak Simon and the children: Putrih, Sinta, Andika and Agustus.Thank you for making me feel at home in the heart of Borneo!Ibu Maria, Ibu Sodak, Nenek Lama and Nenek Bui were generous informants about their traditions.I would like to thank the four local field assistants: Bapak Dobet, Bapak Endan, Bapak Ovit and Bapak Lombok for their help and friendship.They were like caring big brothers to me; they never got tired of helping me and making me laugh.Bapak Dobet, my dear friend and the best storyteller in Nanga Dua kept a watchful eye on me and saved me from many dangerous situations.Thank you, Bapak Dobet.
I am grateful to Bayuni Shantiko, Bapak Wyiono, Bapak Rizali and Landung, who were great companions on the field.Special thanks to Bapak Rizali, who did a great job of identifying the plant species.I also would like to thank the CIFOR staff: Danan Hadi for being an untiring support in mapping and Tina Taufiqoh for her teachings.

Introduction
94.4 million ha in 2010 (World Bank 2010;FAO 2011).This induces rapid habitat loss, threatening a high number of endemic species with extinction.
Southeast Asia had the highest deforestation rate among tropical regions in the world at the end of the 1990s (Miettinen et al. 2011).The Indonesian part of Borneo, called Kalimantan, covers an area of 54 million ha.In 2002, approximately 50% of this area, or 26.7 million ha, was still under forest, but this has been steadily diminishing due to deforestation (Fuller et al. 2004;Miettinen et al. 2011; Figure 1).A great number of species can be found in its different

Forests in Kalimantan: A changing environment
Indonesia is blessed with an extraordinarily rich natural and cultural heritage.It contains 10% of the remaining global tropical rainforest, placing it in third place, after Brazil and the Democratic Republic of Congo (FAO 2010).These tropical forests house a high biological diversity and provide multiple goods and services.Deforestation for cultivating crops created radical changes during the last decades, resulting in a forest cover drop from 162 million hectares in 1950 (Global Forest Watch, 1995) to Source: Ahlenius (2007) forest types and habitats.Kalimantan is part of the Sundaland biodiversity hotspot, which means its ecosystems are a priority for conservation issues (Myers et al. 2000).Its forests are home to more than 3000 tree species, including 267 species of the Dipterocarpaceae2 family, of which 155 are endemic to Borneo (Ashton 1982).The lowland dipterocarp forest is one of the most species rich in the world in terms of flora and fauna (Whitmore 1988).It grows on mineral soils on altitudes under < 300 m or < 500 m, according to the classification of different authors (Symington 1943;van Steenis 1972;Whitmore 1988;Laumonier 1997), where it gradually changes to hilly dipterocarp forest.
In addition to its natural richness, Indonesia's cultural heritage is extremely diverse.According to Istiyani (2008), there are 168 local dialects in the province of West Kalimantan3 .All over the world, cultural diversity influences both natural resource management and natural diversity (Hill 2008).Numerous publications, such as the Millennium Ecosystem Assessment (2005), demonstrate the links between human well-being and ecosystem services.Directly or indirectly, the Indonesian forests are of great social, economic and environmental importance.The role they play for the national economy, as well as the livelihood of local communities is crucial.

Indigenous-community-based forest management systems in Kalimantan
The forests of Indonesia and their resources have been managed by indigenous groups for millennia using traditional knowledge and customary laws.These community-based practices differ from the management carried out by the government or industrial firms, as they are generally small-scale and based on diverse consumption and cultural needs.Cultivation usually evolves through swidden agriculture and the planting of selected plant and tree species.According to Kleinman et al. (1995), small-scale swidden agriculture is viewed as a sustainable practice, as smallholders are not dependent on "outside inputs based on fossil energy for fertilizers, pesticides and irrigation."Agroforests cover 6 -8 million ha in Indonesia and constitute a major income source for smallholders (Michon et al. 2005).The extracted products include: rubber latex, dipterocarp and benzoin resin, spices, fuelwood, fruits, nuts, bamboo, handicraft material, and medicinal plants.
Hunting and gathering is still practiced in the interior of Borneo.Products extracted from the forest can be used for selling or self-consumption.In West Kalimantan, some Dayak4 communities gather agarwood (gaharu) a resinous substance that forms in the wood of trees, belonging to the Aquilaria genus, when they are infected with a specific fungus (Subehan et al. 2005).This resin is used as incense or in perfume, and is sold on the national and international market.An important source of income for Indonesian smallholders is the growing and tapping of rubber trees (Hevea brasiliensis) (Michon et al. 2005).
The agricultural systems of Kalimantan are traditionally based on swidden agriculture, as it is found in numerous Dayak villages (Jessup and Vayda 1988;Poffenberger and McGean 1993;Comptour 2011).As Kalimantan's soils are poor in minerals and nutrients, shifting cultivation is practiced in order to fertilize the soils through burning of trees (Setyawan 2010).The swiddens, called ladang, are fields grown with upland rice and a broad variety of fruits and vegetables (Gönner 2000;Crevello 2003).
The indigenous forest management systems and local resource uses have maintained human health and protected environments, and they may be a key to sustainability (Crevello 2004;Contreras-Hermosilla and Fay 2005;Sobrevila 2008).These systems are not static or unchanging, but adaptable, flexible and influential uses of diverse resources and natural dynamics (Jessup and Vayda 1988;Gönner 2002).

Kapuas Hulu Regency
This study is conducted in the regency of Kapuas Hulu, in the northeastern part of the West Kalimantan Province (Figures 2 and 3).The climate is equatorial, with over 200 mm of rainfall per month and average mean temperatures of over 20ºC (Fontanel and Chantefort 1978;Oldeman et al. 1980).Trees mostly bear fruits during the wet season, from December to March (Galdikas 2009).Soils in the region are mainly ultisols (Palm et al. 2007).
Kapuas Hulu is called a "conservation regency" as it houses two large national parks and is the source of major rivers and streams.Covering a total surface of 2.9 million ha (BPS-Statistics 2010), the regency has lost 320,000 ha of forests to oil palm plantations (Persoon and Osseweijer 2008)  pictures.The scale does not allow for much detail in terms of landscape and agricultural types.The section in bright green around the village and along the two main rivers refers to a mosaic of secondary regrowth, fallows and gardens.Logged over lowland forest stretches to the north of the area and south of River Mentebah.Further south, the forest seems unaffected by logging activities, giving way to intact lowland forest, which is replaced further up by hill forests (300-800 m of altitude).The kerangas forest, which developed on sandstone, occurs on hills south of the sector, mainly above 600 m altitude, and on an important section below 300 m.

Methods
This study describes local people's interactions with their natural environment and refers to ethnobiology or the science of how people understand and use their environment, including plants and animals, based on their culture (Pieroni et al. 2005).The field survey was conducted over a 3-month period from April to July 2012.
Preliminary preparation for the study included an intense course in the Indonesian language over a 2-week period.
This study examined three different crucial sources of information to obtain insight in peoples' perceptions and their environment: (i) knowledge gained through observing peoples' activities, (ii) knowledge provided by local people, and (iii) knowledge gained through scientific measurement (Lynam 1999).

Perception of the land use, landscape and species value
To get a deeper insight into the different land uses and the values the villagers attributed to the different landscapes6 and species, participatory research methods were used.People participated on a voluntary basis.

Focus group discussions
Two topics were examined with the villagers in focus group discussions (Kitzinger 2003).In the first session, 7 women and 1 man were asked to name and define the existing land types, in order to get an overview of the peoples' understanding of existing landscapes and land-use units.During the second meeting, composed of 11 women and 3 men, different categories of uses were defined.
Lists were then established containing the most important species (local name), derived from the different land-use types, for each use category.In order to work in accordance with the villagers' understanding of the different landscapes and land uses, the established classifications were subsequently used for all further surveys, such as the pebble distribution method (see below).

Community landscape mapping
Community mapping is a powerful tool to localize the different landscapes, vegetation cover type and the associated specific uses, as viewed by local people (Chambers 1994;Corbett 2009).As well as a base map containing the main rivers and paths, villagers were asked to draw the borders of their territory, the natural resources, the different types of land and the related uses, such as fallows, protected areas, etc.For efficiency, symbols for the different land uses were created before the meeting, in accordance with the land-type classification established by the villagers during the focus group discussion.To ensure that women expressed themselves freely, men and women were divided into two different groups of four people each and each group was consulted separately.

The pebbles distribution method (PDM) or scoring exercise
The pebbles distribution method (PDM) or scoring exercise helps to assess the "importance" of biodiversity to people who rely on natural resources (Carol et al. 1999;Sheil et al. 2003).The method was used during two meetings, one with eight women and one with seven men (Photo 1).

Importance of the land types for use categories
To understand which types of land are valued for what kind of use, informants were asked to distribute 100 pebbles on illustrated cards, representing the different types of land units, according to their importance in terms of different resource-use categories.In order to facilitate understanding, the resource-use categories were also drawn on cards (Photo 2).A high number of pebbles placed on a card means that a high value is given to this land unit and vice versa.

Income
The PDM was also used to assess the value of each type of land use with regard to income.The participants were asked to place the pebbles on the land unit cards according to their relative importance with regard to income.The informers were asked to name income-generating products and species and their price.

Past-present-future
In a context of rapid land-use changes, it was important to enquire about changes in perception over time.The overall importance of the landscape units 30 years ago, now and in 20 years time was evaluated.The villagers were asked to distribute the pebbles on the cards for the present, the past and the future.The data was analyzed using Excel to produce graphs and facilitate visualization of the results.

Medicinal plant use
An additional study was conducted in order to gain knowledge about traditional plant use of the villagers.The choice of the key informants was restricted mainly to women, as men were not present in the village much during the daytime and social constrains forbade field excursions with one man only.Three men were questioned during expeditions in the forest.Among the six surveyed women were three key informants, who are acknowledged as experts in traditional healing practices.Ibu Maria (48 years old), the wife of the village chief Bapak Simon, is consulted by many villagers for all types of diseases.Nenek Lama and Nenek Bui (both around 70 years old) help women to give birth.The womens' home gardens were studied in detail as they plant medicinal plants close to their houses.
During daily field excursions, wild medicinal plants were gathered and conserved in ethanol.This herbarium collection enabled scientific identification of most of the species at CIFOR headquarters, Bogor 7 .The location, local name, use and route of administration were recorded for each plant.When a person became ill, the healing procedures used by Ibu Maria were observed and discussed with her.

Ecological analysis of the different land use units through tree diversity
In order to make the link between the resource management systems of the villagers and the forest environment, the tree diversity found in the different types of land-use areas was assessed.The following seven areas were studied: logged-over forest; fallows of 5, 15 and 30 years old; and three types of primary lowland forests: swamp forest, hill forest and the kerangas (Table 1).The focus group discussions, community maps and suggestions of the key informants enabled us to choose the study sites according to the different land and resource uses.

Data collection
For each land type, one plot enabled sampling of 0.2 ha of vegetation, using five small 20 m Χ 20 m subplots (Figure 5) per type (swamp, hill, kerangas, logged-over dipterocarp forest and the three age classes of fallows).Seven of these plots in the seven different land-use units were analyzed, which corresponds to a total area of 1.4 ha.Within the scope of another CoLUPSIA vegetation assessment in the swamp, hill and kerangas forests, 10 of these survey plots included 7 All scientific names of the collected medicinal plants and trees were verified using The Plant List (2010).a total of 3 areas of 2 ha each.Between each of the 10 plots, a distance of 100 m was established (Figure 6).Out of these 10 plots, one data set of one plot was chosen randomly and used in this study, in order to compare the data from the swamp, hill and kerangas forests with the data sampled in the fallows and logged-over forest.
For each plot, leaf samples of each tree species were collected and their local name was recorded, which allowed scientific identification at CIFOR, Bogor.
A field herbarium folder with dried leaves of each species was made to crosscheck every local name with the key informants in the village.
In each plot, the diameter at breast height (dbh) was measured 1.3 m from the ground or above trunk  deformations, for each tree that had a diameter ≥ 10 cm.The dbh was measured using a diameter tape, which gives diameter values in centimetres.If the tree had a high buttress, ladders or lianas were used to climb the tree and measure the diameter above the buttress (Photos 3 and 4).As these are permanent plot sites, each tree was numbered with a metal plate.The point at which diameter measurement was taken was marked by painting the trunk with a white line (Photo 5).
Four local field assistants were hired.Bapak Endan and Bapak Ovit were excellent tree climbers and gathered the leaves for the specimen collection.Bapak Dobet was the most knowledgeable about tree species and Bapak Lombok helped with the establishment of the plots.2).It ranges from 0 to 200, and the larger the IVI, the more dominant a species is in the land unit.After calculations are completed, species are ranker from high to low IVI in order to compare the land units with each other.

Data collection
In order to assess the knowledge about trees and medicinal plants of a broader spectrum of villagers, individual interviews were conducted.The people were asked to name 15 species of trees, to explain what kind of uses they had for them and where they usually found them.The same question was used to assess the villagers' knowledge about medicinal plants, including the route of administration (Appendix 1).This approach provides us with an idea of what species is culturally important to a person (Borgatti and Halgin 1998) and what species the villagers know best or use generally most.The informants were randomly chosen among 10 men and 10 women.For each age class (< 30, 30-45, 45-60, >60 years old) 2 to 3 men as well as women were questioned, in order to represent all ages of the society.

Data analysis
The overall percentages of answers was calculated by summing the lists' lengths of each gender and topic group and dividing it by 150, which is the total number of possible answers (10 participants Χ 15 species each).
Using the program ANTROPAC (Borgatti, 1992) the difference in species quoted between the different gender and age groups was analyzed.ANTROPAC enables to calculate the Smith's index of salience (Smith S9 ).It highlights the psychologically or culturally important tree and medicinal plant species and differentiation in species choice and the degree of importance according to gender.Species with the greatest salience are those that respondents list the most often and tend to recall before other species (Borgatti and Halgin 1998).Smith S does not only put statistic weight on the rank of each species in the list, but also the overall length of each list (Balée 2010).Species that were named by at least two informants were considered and the 10 highest Smith S values for the men as well as the women lists analyzed were recorded.Men gather gaharu in the forest, which is extracted from Aquilaria microcarpa (gaharu bukit) or Aquilaria beccariana (gaharu pantai) trees, to sell in the village or in nearby markets (Semangut or Mentebah).Due to time-consuming gold mining activities, only a few people grow and tap rubber trees.While women mostly work in the village, swiddens or gold-mining camps, men wander far out into the forest in order to hunt or gather gaharu.People commonly complained that the surrounding forests are "emptied" of animals, such as wild boar, birds or apes, and that prices for meat within the village steadily rise, as hunters have to walk further.All adult respondents agreed that when they were children, animals could be found in abundance close to the village, but now hunting pressure has drastically reduced their numbers.
Hutan rimba is referred to as primary, "untouched", forest in English, although some trees might have been extracted by villagers 50 or more years ago.The primary swamp forest occupies small depressions at the foot of the hills, with a large number of small rivers and creeks.Thirty years ago, a Malaysian company selectively extracted trees out of the lowland forest, creating the logged-over or secondary forest and the earth road.Villagers also extract timber and wood on a much smaller scale for housing, mining camps or boat construction.Due to fear of erosion or because the soils are too nutrient poor for agriculture, villagers do not cut trees in certain areas.These "protected forests" correspond with zones covered by kerangas forests.
Although the villagers seem not to include them as a distinctive land-use unit in their categorization of the landscapes, they recognize kerangas as a different forest type.Swiddens are agricultural fields cleared and planted with rice, vegetables, fruits and medicinal plants for one year, before a new field is opened.Fallows are old swiddens, which are left fallow for soil recovery for a certain amount of years.
Once the farmers estimate that the soils are ready, which may take up to 30 years, fallows are converted to swiddens again or rubber gardens.The current rubber trees are still young, at around 1-15 years old.As rivers represent an important food (fish) and income (gold) source, they were also named as a main land-use type.
During the second meeting nine land-use categories (Figure 9) were registered.The list of important animal and plant products for each of these categories totaled 110 species, of which 74 were gathered in primary forest, 24 in the swiddens and 12 in fallows.Four different species of gaharu were, for example, named as marketable products (Appendix 3).In this section rubber was not mentioned by the villagers.The category containing the highest amount of species was: hunted wildlife (with 29 animals mentioned) followed by food and medicinal plants.

Community landscape mapping
The men created a map that was more precise and correct in terms of distances and localizations then the women's map.The gap in territorial knowledge between men and women, highlighted through the participatory mapping process, reflects some of the realities of the women's world.Women do not have as much knowledge of the landscape as men as they spend more time in the village, while men wander far out into the forest, sometimes for months.This creates very different views of the environment.
The map established by the men (Figure 10) shows that the swiddens of this year were planted along The red squares were added to the map later to indicate the location of the tree diversity survey plot sites.

PDM scoring exercices
Importance of the land types for use categories Two graphs (Figure 11) represent the relative importance of the different land-use types for each land-use category, with respect to the data (Appendix 4) collected during the meetings.Generally, men tended to place either very large or very small amounts of pebbles on the landuse cards, while women distributed the pebbles more evenly.The importance men accorded to the different land-use types seems to be more contrasted.Both men and women expressed a preference using the pebbles for the hill forest, for all the use categories, except for fodder.Since it is forbidden to cut trees, the "protected" forest area falls into a less important category.The only use women had in this type of forest is for gathering medicinal plants and men used this forest for hunting.The rivers and swiddens were important for providing a food supply.Women found rubber gardens were also crucial in this category of use, while men negated this land type.Women seem also to have more use for swiddens, while men only thought of them as fodder and food sources, women gather fuelwood and medicines there.
A close-up look on the land-use category "medicinal plants" (Figure 12) reveals that women placed pebbles on the land types and men placed them on six different land types.Men argued that no medicinal plants are to be found in swamp forest, swiddens, rubber gardens and "protected" forests.Women recognized that medicinal plants are gathered in each land unit.It can be deduced that woman gather medicinal plants in more landscape units then men.

Income
While men placed a high value (Figure 13 and Appendix 5) on primary hill and swamp forest for their income, women found rubber gardens and swiddens more valuable.In contrast to women, men did not find secondary forests and fallows of 1-5 years old important for income.Both groups scored the "protected" forest as being not important to income.

Past-present-future
According to this PDM, there are perception changes over time (Figure 14 and Appendix 6).For the past and the present, men put a high number of pebbles on primary swamp and hill forests.They argued that their importance will drop, as these land types might disappear in the next 20 years.In the meantime, secondary forest and "protected" forests gain importance for the future.Men and women placed high scores on current rubber gardens, which seemed to have less importance in the past.Women argued that rubber gardens are crucial, as they can generate income and can be converted to swiddens.According to men, swiddens will lose their central role as food sources, as exploitable soils will be too far away from the village in the future.

Traditional medicinal plants and their uses
During this study 125 medicinal plants (Appendix 8) and 9 other types of remedies (Appendix 7) were recorded.The collection contains plants of 54 botanical families, of which 105 were identified to the species and 19 to the genus level.One plant remains unidentified.Ten plants that were given different names by the traditional healer, turned out to belong to 5 species only.
Medicinal uses for the plants collected were very broad.The plants could treat ailments such as stomach ache, headache, toothache, fever, and insect, snake or centipede bites; some were used in childbirth.
The routes of administration and plant parts used varied.For 75 plants the leaves that contain the active ingredient, such as in tea made out of kumis kucing (Orthosiphon aristatus) leaves.The smoke of burned plant parts, for example the root of Ilung asam (Schismatoglottis rupestris) is used as a remedy "to chase Satan" out of the ill person or the house.
Beside the three key informants, only a few people could describe diseases in detail.Ibu Maria distinguished between, for example, three different types of headache.Plants were mostly used in combination; using one alone was rarely seen to be effective.For example, 12 different leaves were used to treat meniali abdominal pain (when the right side hurts).Some diseases require complex preparations and applications of plant mixtures that are the domain of specialists.
Out of the 136 natural medicines sampled, one third were collected in primary forest (Figure 15).Nearly half were collected in the immediate surroundings of the village and the swiddens.Some were found in the fallows and some on the riverbanks.This is not static data, as plants that are planted in the gardens may also be found in fallows.Furthermore, women grow plants that originate in the primary forest in their gardens or near their homes.Out of the 125 medicinal plants, only 38 were planted and 87 (nearly 70%) grew naturally in the wild.

Ecological analysis
The quantity and size (dbh) of trees in the different landscape units shows differences for each 0.2 ha plot (Table 3).The highest density of trees, having a dbh over 10 cm, is to be found in the young 5-year-old fallow (197 trees), followed by the kerangas forest (173 trees), the 15-year-old fallow (162 trees), the 30-yearold fallow (147 trees) and the secondary forest (130 trees).The lowest numbers of tree individuals are in the primary hill (103 trees) and swamp forests (99 trees).There is a difference of nearly 100 trees, between the young fallow and the primary swamp forest.Hill, swamp and secondary forests have relatively few small  The Simpson index (Table 4, Appendix 9) shows that in terms of tree species richness, the swamp trees (dbh up to 20 cm) and the 5-year-old fallow has a large number of small trees.In contrast, big trees of over 60 cm of dbh are only found in the hill, swamp and secondary forest plots.The fallows and Kerangas have a higher amount of small trees, in larger quantities, whereas the primary hill and swamp forests have a smaller number of trees, but with some very large ones.The swamp forest contained some huge trees of nearly 2 m in dbh.The secondary forest, which was selectively logged over 30 years ago, has fewer individual trees than the 30-year-old fallow but has some large individual trees.
The kerangas are distinctive land types, which have sandy soils.The superficial roots are very obvious.The poverty of the soil is indicated by the presence of carnivorous plants such as Nepenthes spp.Poor and shallow soils do not allow the trees to grow tall and large, hence there is a high number of small trees in this area.forest is close to the maximum, with D = 0.96, followed by the kerangas and logged-over forest (both D = 0.94).The hill forest has a D = 0.92, which is slightly higher than the 5-year-old fallows, where D = 0.90.The diversity index drops for older fallows: the 15-year-old fallow has a D of 0.88 and the 30-year-old has the lowest index at D= 0.77.
In terms of IVI, the kerangas, swamp and hill forests contain at least three species of the Dipterocarpaceae family, mainly of the genus Shorea, among their dominant species.They are not dominant in human-caused successional forests.The swamp forest can support trees that are dominant due to their huge basal area such as individuals of Koompassia malaccensis or Alstonia angustiloba.The pioneer species Bellucia pentamera, Macaranga hosei and Ficus variegata are dominant in all the fallows.

Free lists of trees and medicinal plants
The indexes of salience, Smith S, indicate differences in trees and medicinal plants cited by men and by women (Table 5).Mangga, durian and tomau were among the most prevalent and first mentioned trees for both groups.Three medicinal plants, juaran, sabang and kunyit, seemed to be important to the whole community.Nearly all of the people questioned listed 15 out of the 15 trees (93% of answers for the women and 96% for the men).Half of the named trees were used for their fruits and one third of them were used for house construction.The free lists of medicinal plants were hard to establish for most of the men who were surveyed.While women named 80% of the plants in the lists, men had shorter lists, with only 60% of answers.A small number of men displayed an indepth knowledge of medicinal plants, their preparations and routes of administration.
Overall, the lack of fluency in the local language and in Indonesian by the author was a barrier to the field research, especially at the beginning.

Gender-related observations
Central observations in this study were differences in perceptions between men and women.As observed in other Dayak communities (Gönner 2000;Mulyoutami et al. 2009), some tasks were exclusively the men's or the women's domain, although there was a large amount of common labor.Men were underrepresented in this study, especially during the focus group discussions and the survey of medicinal plants.First, they were mostly away during the 3-month study period and second because for me, as a women, contact with men was time consuming to organize and delicate to establish.Nevertheless, the results of the free lists and the PDM, combined with the villagers' opinions, imply that medicinal plant knowledge is generally more of a women's domain, even if some men had profound knowledge of it.According to Caniago and Siebert (1998), Dayak women in rural Kalimantan usually have deeper knowledge of medicinal plants, as it is they who mostly care for their children's health and manage their gardens.

Medicinal plant listing
Traditional medicine is an integral part of the health system in this area, for financial reasons, because of lack of alternatives and because of its efficiency.The relative isolation of Nanga Dua probably supports the use of medicinal plants and the perpetuation of this knowledge down the generations.The collection of medicinal plants gives us a first insight into this traditional custom.Meanwhile, comparing each sampled plant with bibliographic references, would deepen the analysis of the medicinal plants and the knowledge about them.For example jambu air (Senna alata), which is used to relieve 'itchy skin' has been proven to have antifungal properties according to Sule et al. (2011).

Participatory mapping
For the participatory mapping process, the map lacks accuracy and should be considered as a first draft that provides an overview of the area.The participants were unable to draw boundaries of the different land-use units.Furthermore, only four men and four women participants were present for the mapping procedure, and this does not represent the community as a whole.More GPS data from the field, with active participation of the local population would give a more reliable map (Bujang 2004).Maps are an important tool to empower people who rely on land established through customary institutions and local stakeholders should be included in spatial planning (Kurniawan and Hanafi 2004).

The free listing method
Due to lack of time, not all the trees and medicinal plants named in the free lists were sampled.This analysis is therefore based on local names and not on scientific names.It would have been more valuable from an ethnobotanic perspective to do a more detailed study.Instead of asking the informants to name trees and their uses, it would have been better to make a list for each use category, e.g. one list for tree species used for house construction (Quinlan 2005).Furthermore, as the salience index S takes into account the length of the lists, open listing (not restricted to 15 answers only) would have been more relevant.Moreover, data is generally statistically reliable counting from a minimum of 30 lists per topic (Borgatti and Halgin 1998).
In addition, it was observed that some respondents struggled to do this exercise.Indeed, people generally do not think theoretically about trees and medicinal plants.For instance, one 70-year-old woman could not list 15 medicinal plants while sitting in her house, but when she looked for plants for specific diseases or walks in the surrounding area she knew many plants and was consulted by the villagers because of her knowledge.Field interviews seem in this case to be more appropriate.Hence, the free listings approach is not a deep evaluation of the community's knowledge about tree and medicinal plant uses, but is seen as a first approach.

Ecological analysis
Vegetation cover in this area is mainly a forest mosaic of different types of vegetation, influenced to different degrees by human activities.In such a mosaic, especially for secondary regrowth, the problem of representativeness of the sampling is an issue (Wagner et al. 2000).A plot sample size of 0.2 ha appears large enough to characterize fallows, but it may not be statistically reliable in large forest areas.For the dipterocarp forests Ashton (1964) used plot sizes of 0.4 ha, but more recent studies sample 1 ha plots (Poulsen et al. 1996;Small et al. 2004).Some authors suggest use of much larger plots (Laumonier et al. 2010) and the CoLUPSIA project is establishing permanent plots of between 2 ha and 6 ha.
Due to lack of time, not all tree leaves were sampled, but only one per local name for each plot.The local classification does not always coincide with scientific classification.This led to a few mistakes, for example trees which had the same local name but different Latin names.For scientific correctness, each single tree should have been sampled.
The secondary forests and young fallows have high tree diversity indexes.The fact that forest disturbance for traditional slash-and-burn agriculture is done on a small-scale and in the immediate vicinity of primary forest, which serves as species reservoir (Mo et al. 2011), enables fast and tree-species-rich forest regeneration.

The Kerangas
The villagers did not include the kerangas as a distinctive land use in their categorization of the landscape, even if they did recognize this type of forest.This is because apart from gaharu gathering and sporadic hunting, the villagers do not use this forest type for agriculture.The kerangas forests are especially sensitive to disturbance, such as clear cutting or fire, as they grow on shallow, dry, sandy soils (Dennis 1999).According to Meijaard et al. (2005) the kerangas forest areas are unable to recover and produce any valuable vegetation after the trees have been cut.The villagers are aware of that, as they categorized this type of vegetation as forest that is protected from cutting through customary law.One other reason is that there were mostly women present during the focus group discussions about land uses.Women do not look for gaharu or hunt, so it might not seem an important land-use feature to them as they rarely enter the kerangas.

The role of vulnerable forestry resources
During my stay in the village and through the participatory surveys it became evident that the inhabitants of Nanga Dua Village use a broad variety of forest products on a daily basis.Rubber tree tapping is likely to become a more important resource in the future, once the trees are old enough.Local people seemed to be aware of the vulnerability of their forestry resources.The scoring exercises showed that primary forest was seen by local people as at risk of disappearing in the future and represents an important source of resources, such as food, handicrafts, and house and boat construction material.Primary swamp and hill forest play a crucial role as sources of income.As local people use medicinal plants to treat common ailments and illnesses, degradation of the forest may imply a loss of their healthcare options (Shanley and Luz 2003).This research highlights that the majority of medicinal plants originate from the primary forest, either through direct extraction or through selected planting of species gathered there.The fact that villagers observe that wild animals are becoming scarcer raises more questions.Wild animal resource management is not sustainable.A broad spectrum of species are hunted locally, some of which have lower populations and are protected by national law, such as the sun bear (Helarctos malayanus), which is classed as vulnerable on the IUCN Red List (Fredriksson et al. 2008) or the Sunda pangolin (Manis javanica), which is classed as endangered (Duckworth et al. 2008).
It is important to study in detail these aspects of sustainable natural resource management and support the local community in order to ensure the lasting presence of wildlife.The scarcity of wildlife may be connected to the absence of fruit during the survey period.A stay of 3 months is not long enough to fully understand people's resource management issues, especially as it depends on seasonal rain variations.
This study brings new insights on a Dayak Mentebah community and the ways they perceive and use their environment.
The communities of Nanga Dua and neighboring villages are dependent on forestry resources.Despite the economic incomes earned through gold mining along rivers, people still rely on hunting and gathering; and on the fruits, vegetables and rice from their swiddens.Forest products are widely used for basketry, construction of houses or boats, fuelwood and food.The participatory surveys show that primary swamp and hill forest are important reservoirs of resources and that the people of Nanga Dua rely on them and know how to use them.
The traditional, consecutive land clearing for shifting cultivation in this area causes the formation of vegetation patches with different succession stages.These human-modified areas, which are mixtures of secondary regrowth and gardens are very rich biologically.Exploitation is on a smallscale and the swidden agriculture is embedded into the surrounding primary forest landscape, which explains the high diversity of tree species in the different land-use types.The secondary forest and young fallows have an important conservation value.
Hill kerangas forests, where sporadic hunting and gaharu gathering is practiced, are protected from timber extraction by traditional law.
Traditional medicine remains an integral part of the health system in the area.Local people have remarkable knowledge of species and their uses as remedies.The relatively isolated location of the village probably sustains the traditional lifestyle.Meanwhile, socioeconomic, traditional and ecological settings are changing fast.People hope that the old logging road will be restored, which would give better access to the district's road network.Through this, access to better healthcare options and to other economic activities would become possible.
However, the opinions and needs of local people should be considered for any development project on their land.The rights to own and decide upon their ancestral lands have to be respected, in order to protect the rich cultural and natural heritage of the region.
Ibu Tuman making a basket used for fishing Different types of baskets Mats used for drying rice in the sun Ibu Sodak creates a hat, named Tangui, using peropok and rattant A fish trap made out of rattan

Figure 1 .
Figure 1.Deforestation in Borneo: Steady depletion of forest cover between 1950 and 2005, and projected loss up to 2020.

Figure 2 .Figure 3 .Figure 4 .
Figure 2. Location of the Indonesian province of West Kalimantan, in green.Source: Adapted from maps established by Danan Hadi, CoLUPSIA

Photo 1 .
Photo 1.Some of the men during the scoring exercise.(Photo by Edith Weihreter.)

Figure 5 .
Figure 5. Setting of the 0.2 ha plots used in the fallows and logged-over forest.

Figure 6 .
Figure 6.Zoom on 2 out of 10 plots laid in a row in the lowland hill forest as well as the kerangas.The orange plot symbolizes the plot which was randomly choosen for this study.

Figure 7 .
Figure 7. Calendar of swidden agriculture and other activities.

Photo 7 .Figure 8 .
Photo 7. River Penungun to the left and river Mentebah to the right, loaded with sediment.(Photo by Edith Weihreter.)

Figure 9 .Figure 10 .
Figure 9.The eight land-use categories established during the focus group discussion, cards used for the PDM.
the old logging road.The farthest field is a 3 hour walking distance (approximately 12 km) from the village, alongside the border of the village Nanga Payang area.This logging road is the only land connection to the district's road network, as it is the only path which is drivable by motorcycle.The main walking paths are included on the map; apart from these the forest has a dense network of small, temporary hunting paths.The fallows lie around the village and the two main rivers.The rubber gardens are close to the village and are easily accessible by boat.The territory has many small rivers and only some were incorporated into the map.Most of the area is occupied by hill forest.Gaharu is exclusively gathered on Bukit Tuhan, the mountain range south of the territory, which contains mainly Keranga forests.It is accessible by boat and by walking through difficult and very steep terrain (1 or 2 days travel).The area contains one cave, inhabited by a small population (around 50 birds) of cave swiftlets (Aerodramus fuciphagus).The edible nests are not exploited by people of Nanga Dua, but exploitation rights are rented to people of Nanga Payang.

Figure 13 .
Figure 11.Importance of each land unit with regard to different use categories (men and women groups).
Figure 14.Change of perception in time, past-present-future (men and women groups).

Table 1 . Plot site description. Land unit type Local name Mean altitude of plot sites (m)
Photo 3. Bapak Endan and Lombok climb a tree with huge buttress for dbh measurement.(Photo by Edith Weihreter.)

Table 2 . Calculations for the importance value index according to Curtis and Cottam (1962) and Hédl et al. (2009).
in many cases primary school is the only education that children receive.Agriculture, fishing, hunting 11 and gathering is mainly done for subsidence.The villagers' agricultural system is based on annual swiddens.Traditional land tenure rights are family-based.New fields are opened every year using the slash-and-burn technique.Rotation is made on ancient fallows or on new soils that are cleared in primary forest.The detailed calendar of 11 Men hunt using handmade rifles, and the gunpowder is made out of the wood of kayu tomau (Syzygium cymosa).Photo 6.Some houses of Nanga Dua.(Photo by Edith Weihreter.)

3 Results 3.1 Activities, history and socioeconomic situation of Nanga Dua The
area has been inhabited for centuries, but the village was formally established in 1984, and currently has a population of 490 inhabitants.Due to an increased number of villagers, the traditional longhouse architecture was abandoned and people now live in individual houses, regrouped into one or more households (Photo 6).Access to the village is either by boat or through a former logging road by motorcycle.Travel time depends on rainfall.When it does not rain for a few days, most of the rivers and creeks become too low for navigation.When the rain is heavy the dust road becomes too muddy for motorcycling.Due to very high transportation costs 10 , the inhabitants are relatively isolated.They rarely or never go to see a doctor for disease treatment or vaccination and rely mostly on traditional medicinal plant treatment.