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Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Forest fights in Haripur, Northwest Pakistan
    Nizami, A. - \ 2013
    Wageningen University. Promotor(en): Leontine Visser, co-promotor(en): Paul Hebinck. - S.l. : s.n. - ISBN 9789461734556 - 257
    ontwikkelingsstudies - sociologie - politieke processen - acteurs - actor-network theorie - samenleving - natuur - bossen - bosbouw - staat - bosbranden - ecologie - vrouwen - pachtstelsel - pakistan - development studies - sociology - political processes - actors - actor-network theory - society - nature - forests - forestry - state - forest fires - ecology - women - tenure systems - pakistan

    This thesis is an inter-paradigmatic exchange between political ecology and post-structuralist interpretations of actor-structure relationships. The study is founded on multiple discourses where different interpretations of a particular phenomenon by various actors have been analysed. The thesis is meant to show that relationships between society and nature are dynamic, entail multi-sited struggles among many actors at several terrains and are deeply rooted in earlier history.The study transpires that the forest is shaped by a loosely knit network of actors that are linked together by a kaleidoscope of rights, claims and social relationships which seem to determine the fate of the forest in a village.

    Chapter 2 elaborates the theoretical foundation and methodological trajectory of this thesis. The concept of arena is central and analytically useful for this study as it connotes and involves social actors, their social relationships, practices and struggles between them. The notion of social arena is a metaphor for the site or place where action takes place between social actors. These places are not limited by geographical, natural or administrative borders. Arenas are social locations in which contests over issues, resources, values and representations take place. These are either spaces in which contestation associated with different practices and values of different domains takes place; or they are spaces within a single domain where attempts are made to resolve discrepancies in value interpretation and incompatibilities between actor interests. I argue that the forest as a social arena stretches beyond its natural and physical borders.The arena as the site of the struggle is not just geographically confined within natural (e.g. forest) and/or administrative (e.g. political) boundaries but it stretches beyond the locality. These arenas are diverse, they overlap and co-exist, and the boundaries at a given time are defined by networks of relationships between forest users and consumers, relationships between the State, bureaucrats, forest owners, dwellers, and so on.

    Chapter 3 gives a detailed account of history of Haripur and how forests were legally categorised and distributed. History helps understand the political alliances and the power struggles in the region, the district, and (sub district) Khanpur. The State, during British rule introduced a new management regime for natural resources which changed the entire social landscape of Khanpur by attaching private property rights to the trees as well as forest lands in the region. The government authorities, notably the Forest department have most often seen forest dwellers destructive for the forest, depleting its resources and interfering with nature. This premise lays foundation of mistrust between people and the government. Contrary to this, the initiatives to introduce people in forestry governance are based on the realisation that the ownership, or at least management control over forests, is critical to responsible management by the people.

    Chapter 4 provides a detailed account of how the Forest department operates in relation to people and forest resources. There are multiple scales of articulation, alliances and struggles within and around the department and these positions are changeable from time to time with several internal and external factors. The case of Forest department manifests that the State is to be seen as a multifaceted organ and not as an individual actor. Structural changes were introduced in the department but the core on which the foundation of the department was laid, was never changed. Many women firmly believe that the department must continue to use authority to control local people who cause degradation. Each reform initiative taken in the name of participation ended up with basically continuing the same centralised system. Forests were never handed over to the community along with management responsibility (e.g. Guzara forests). Only joint management of forests was enacted – yet not implemented. Trust remained a major issue in all these struggles.

    The subject of forest fire, which I perceive and have experienced as a strong manifestation of resistance and also as a tool to manipulate natural resources, has been dealt with in different places in this thesis, but particularly in Chapter 5. Burning forests is an old practice for clearing land for agriculture.Fire therefore had a significant role in defining farmers’ territories. Gradually these practices changed but grazers continued to light up forests to produce lush green grass for their livestock. This led to a persistent discourse based on appropriating every fire incident to the grazers’ practices. This study highlights that fire is now increasingly used as a management tool for manipulating the resource. Firewood collectors and big owners use fire for obtaining dry firewood or build the case for felling dead / dry trees which is allowed in the policy after ban on green felling. Even if fires may occur due to the will of the forest owner, the policy blindly holds grazersresponsible for their wasteful and damaging practices. The collectors of Non-Timber Forest Produce (NTFP), mostly women, are not happy with fire since their resources are burnt down due to the productive fire requirement of Chir pine (Pinus roxburghii). There is an incline in the graph of forest fires, decreasing self initiative among people to control fires, along with the Forest department’s management bias towards Chir pine trees in fire control operations; these concerns echo in various voices from the field. The chapter also highlights a form of connivance between the owner and the occupants of lands (peasants / tenants) and also the owners and Forest department staff.

    Chapters 6 deals with actors in their struggle to secure their rights to the forest through acquiring forest land title deeds. This initiative from the side of the new owners can be understood as a response to what is explained in Chapter 5. No forests have been handed over with management responsibilities to non owner forest users in nearly one and a half centuries. Non owners have resorted to buying forest lands in little parcels in creating private forests. This way, new meanings are given to the forest and new spaces are created through tactical networking among various actors. Field evidence and opinions from several actors suggest that Reserved forests are frequently being accessed by people for their needs in a de facto manner. Several new owners have acquired land entitlement comprising small pieces of lands which do not have a huge timber value in future. Followed by this, it is also visible that the nature of power in the contemporary society of Khanpur (and beyond) is changing. Power, which was once measured through landholding, is now measured through other symbols, such as political connectivity and affiliation.

    Regular access to NTFP by non-right holders for the sake of earning an income (Chapter 7) is an illustration of their struggle, or more strongly put, an in-between expression of resistance. Poor women remain invisible in their daily practice to access NTFPs. They use spaces that are considered undesirable by other forest actors. These spaces cannot be completely separated within the social arena, but they are knitted into the day to day practices of people. State intrusion into women’s customary and de facto practices concerns them. They fear that this will only reduce their chances of earning a modest livelihood from the forest. However, the women are also highly creative in reshaping their practices and relationships with every change that takes place around them. Firewood collection is the most visible, uninterrupted and non-compromising activity for women. In their daily struggle to feed the family, they virtually manage and control the forest. Contrary to this, women are not part of any dialogue on forestry reform. They need to be part of the negotiation process in which their spaces remain secure. The most important challenge is to create the mechanisms for discussion, negotiation, and arbitration of gendered access regimes under a variety of circumstances.

    Mobile sensor networks for environmental monitoring
    Ballari, D.E. - \ 2012
    Wageningen University. Promotor(en): Arnold Bregt, co-promotor(en): Sytze de Bruin; M.A. Manso Callejo. - S.l. : s.n. - ISBN 9789461732279 - 142
    milieumonitoring - draadloze sensornetwerken - sensors - bemonsteren - modellen - bosbranden - environmental monitoring - wireless sensor networks - sensors - sampling - models - forest fires

    Vulnerability to natural disasters and the human pressure on natural resources have increased the need for environmental monitoring. Proper decisions, based on real-time information gathered from the environment, are critical to protecting human lives and natural resources. To this end, mobile sensor networks, such as wireless sensor networks, are promising sensing systems for flexible and autonomous gathering of such information. Mobile sensor networks consist of geographically deployed sensors very close to a phenomenon of interest. The sensors are autonomous, self-configured, small, lightweight and low powered, and they become mobile when they are attached to mobile objects such as robots, people or bikes.

    Research on mobile sensor networks has focused primarily on using sensor mobility to reduce the main sensor network limitations in terms of network topology, connectivity and energy conservation. However, how sensor mobility could improve environmental monitoring still remains largely unexplored. Addressing this requires the consideration of two main mobility aspects: sampling and mobility constraints. Sampling is about where mobile sensors should be moved, while mobility constraints are about how such movements should be handled, considering the context in which the monitoring is carried out. This thesis explores approaches for sensor mobility within a wireless sensor network for use in environmental monitoring. To achieve this goal, four sub-objectives were defined:

    Explore the use of metadata to describe the dynamic status of sensor networks. Develop a mobility constraint model to infer mobile sensor behaviour. Develop a method to adapt spatial sampling using mobile, constrained sensors. Extend the developed adaptive sampling method to monitoring highly dynamic environmental phenomena.

    Chapter 2 explores the use of metadata to describe the dynamic status of sensor networks. A context model was proposed to describe the general situation in which a sensor network is monitoring. The model consists of four types of contexts: sensor, network, sensing and organisation, where each of the contexts describes the sensor network from a different perspective. Metadata, which are descriptors of observed data, sensor configurations and functionalities, are used as parameters to describe what is happening in the different contexts. The results reveal that metadata are suitable for describing sensor network status within different contexts and reporting the status back to other components, systems or users.

    Chapter 3 develops a model which describes mobility constraints for inferring mobile sensor behaviour. The proposed mobility constraint model consists of three components: first, the context typology proposed in Chapter 2 to describe mobility constraints within the different contexts; second, a context graph, modelled as a Bayesian network, to encode dependencies of mobility constraints within the same or different contexts, as well as among mobility constraints and sensor behaviour; and third, contextual rules to encode how dependent mobility constraints are expected to constrain sensor behaviour. Metadata values for the monitored phenomenon and sensor properties are used to feed the context graph. They are propagated through the graph structure, and the contextual rules are used to infer the most suitable behaviour. The model was used to simulate the behaviour of a mobile sensor network to obtain a suitable spatial coverage in low and high fire risk scenarios. It was shown that the mobility constraint model successfully inferred behaviour, such as sleeping sensors, moving sensors and deploying more sensors to enhance spatial coverage.

    Chapter 4 develops a spatial sampling strategy for use with mobile, constrained sensors according to the expected value of information (EVoI) and mobility constraints. EVoI allows decisions to be made about the location to observe. It minimises the expected costs of wrong predictions about a phenomenon using a spatially aggregated EVoI criterion. Mobility constraints allow decisions to be made about which sensor to move. A cost-distance criterion is used to minimise unwanted effects of sensor mobility on the sensor network itself, such as energy depletion. The method was assessed by comparing it with a random selection of sample locations combined with sensor selection based on a minimum Euclidian distance criterion. The results demonstrate that EVoI enables selection of the most informative locations, while mobility constraints provide the needed context for sensor selection.

    Chapter 5 extends the method developed in Chapter 4 for the case of highly dynamic phenomena. It develops a method for deciding when and where to sample a dynamic phenomenon using mobile sensors. The optimisation criterion is to maximise the EVoI from a new sensor deployment at each time step. The method was demonstrated in a scenario in which a simulated fire in a chemical factory released polluted smoke into the open air. The plume varied in space and time because of variations in atmospheric conditions and could be only partially predicted by a deterministic dispersion model. In-situ observations acquired by mobile sensors were considered to improve predictions. A comparison with random sensor movements and the previous sensor deployment without performing sensor movements shows that the optimised sensor mobility successfully reduced risk caused by poor model predictions.

    Chapter 6 synthesises the main findings and presents my reflections on the implications of such findings. Mobile sensors for environmental monitoring are relevant to improving monitoring by selecting sampling locations that deliver the information that most improves the quality of decisions for protecting human lives and natural resources. Mobility constraints are relevant to managing sensor mobility within sampling strategies. The traditional consideration of mobility constraints within the field of computer sciences mainly leads to sensor self-protection rather than to the protection of human beings and natural resources. By contrast, when used for environmental monitoring, mobile sensors should above all improve monitoring performance, even thought this might produce negative effects on coverage, connectivity or energy consumption. Thus, mobility constraints are useful for reducing such negative effects without constraining the sampling strategy. Although sensor networks are now a mature technology, they are not yet widely used by surveyors and environmental scientists. The operational use of sensor networks in geo-information and environmental sciences therefore needs to be further stimulated. Although this thesis focuses on wireless sensor network, other types of informal sensor networks could be also relevant for environmental monitoring, such as smart phones, volunteer citizens and sensor web. Finally, the following recommendations are given for further research: extend the sampling strategy for dynamic phenomena to take account of mobility constraints; develop sampling strategies that take a decentralised approach; focus on mobility constraints related to connectivity and data transmission; elicit expert knowledge to reveal preferences for sensor mobility under mobility constraints within different types of environmental applications; and validate the proposed strategies in operational implementations.

    Verantwoordelijkheden bij risico- en crisisbeheersing van bos- en natuurbranden : taken en bevoegdheden bij risicoberheersing, bestrijding, nazorg en herstel en een overzicht van de hiaten in regelgeving en taakverdeling
    Raffe, J.K. van - \ 2011
    Wageningen : Alterra, Wageningen-UR (Alterra-rapport 2210)
    bosbranden - natuurbranden - voorkomen van branden - brandcontrole - bevoegdheden - nederland - natuurgebieden - forest fires - wildfires - fire prevention - fire control - competences - netherlands - natural areas
    In 2007/2008 is gekeken welke partijen een rol spelen bij de risico- en crisisbeheersing van (grote) bos- en natuurbranden, wat hun rol precies is en welke taken en bevoegdheden ze hebben. Ook is geïnventariseerd welke hiaten er zijn in de bestaande taakverdeling en regelgeving. Hiaten die de oorzaak kunnen zijn dat natuurbranden ontstaan en kunnen uitgroeien tot een ramp. De inhoud van het rapport was toen dermate gevoelig dat pas in 2011 is besloten dit rapport uit te brengen.
    Bosbrand en klimaatverandering
    Schelhaas, M.J. ; Moriondo, M. - \ 2007
    Vakblad Natuur Bos Landschap 4 (2007)8. - ISSN 1572-7610 - p. 13 - 13.
    bosbranden - bosbeheer - klimaat - forest fires - forest administration - climate
    Elke zomer zijn er meldingen van bosbranden in Zuid-Europa. Vooral de branden in Griekenland kregen afgelopen jaar veel media aandacht. Het weer heeft duidelijk effect op het risico op (bos)branden en het gevaar ervan. In welke mate klimaatverandering zal bijdragen is niet te zeggen. Andere factoren zijn daarbij van belang, zoals o.a. terreinomstandigheden. De terreinbeheerder kan maatregelen nemen in de sfeer van brandsingels en soortensamenstelling
    Spatial matters : how spatial patterns & processes affect savanna dynamics
    Groen, T.A. - \ 2007
    Wageningen University. Promotor(en): Herbert Prins, co-promotor(en): Frank van Langevelde. - [S.l.] : S.n. - ISBN 9789085046905 - 151
    savannebossen - savannen - ruimtelijke verdeling - ruimtelijke variatie - patronen - impact - herbivoren - bosbranden - savanna woodlands - savannas - spatial distribution - spatial variation - patterns - impact - herbivores - forest fires
    Dit proefschrift laat zien dat vuur en herbivorie in staat zijn om ruimtelijke patronen te creëren en in stand te houden. Bovendien laat het zien dat het negatieve effect van vuur op bomen minder wordt als bomen in groepen in de ruimte zijn georganiseerd. Ruimtelijk heterogene ecosystemen blijken minder gevoelig te zijn voor plotselinge verschuivingen, dan homogene gebieden. Echter, zodra een savanne eenmaal geheel verbost is, zal het niet gemakkelijk terugkeren naar zijn oorspronkelijke staat
    Spaceborne radar monitoring of forest fires and forest cover change : a case study in Kalimantan
    Sugardiman, R.A. - \ 2007
    Wageningen University. Promotor(en): Reinder Feddes, co-promotor(en): Dirk Hoekman. - [S.l.] : S.n. - ISBN 9789085046042 - 190
    tropische regenbossen - regenbossen - bosbranden - kroondak - remote sensing - radar - monitoring - digitaal terreinmodel - kalimantan - tropical rain forests - rain forests - forest fires - canopy - remote sensing - radar - monitoring - digital elevation model - kalimantan
    The devastation of tropical rain forests has been proven to have a significant effect on global climate change. The sustainability of these forests becomes a major concern for the international community. The Indonesian Ministry of Forestry (MOF) is eager to carry on forest inventory activities and to generate forest resources information.Advanced spaceborne radar techniques are a very promising tool to monitor forests. This technique is complementary with the existing spaceborne optical imagery which suffers too much from cloud cover. Radar provide reliable information on a regular basis and has been applied in various types of applications e.g. forest classification.

    The approach presented in this thesis includes. Firstly, multi-temporal classification of spaceborne Synthetic Aperture Radar (SAR) data using Iterated Conditional Modes which is proposed as a fast step of Maximum Likelihood classification in order to circumvent the slow image segmentation step. Secondly, slope correction dealing with steep slopes that considerable has geometric distortion. Thirdly, textural analysis has been applied to derive additional information layers in multi-temporal classification from fine structures in the radar images.

    The study focuses on three test site areas i.e. Sungai Wain test site area, the Gunung Meratustest site area and the NASA AirSAR PacRim-II test site area.This area experienced long drought periods associated with the El Niño Southern Oscillation (ENSO)phenomenon. For this study the severe ENSO event of 1997 - 1998 is of particular interest.Forestfires occur almost every year in this test site area, however,each event is specific in intensity and extent. A longer time series ofradar images takes every event observations into account.

    The results show high accuracy ranging from 85.2% to 98.8% for almost all land cover types. Slope correction has positive effect, but in accuracy does not seem to be very high. It is showed that the induced slope correction is around 1 dB while values up to 10 dB were expected. The resolution of the digital elevation model is an important factor for the correction of relief in spaceborne SAR data. When the resolution is too coarse, i.e. spatial features of slope correction are coarser than the actual structures; the pattern of relief will be flattened out. Utilization of textural features yields a significant improvement of overall classification accuracy, which increases from 36.5% to 48.5%.

    The approach developed for the Gunung Meratus has a wide applicability. This approach seemed to be sufficiently mature to apply it for others areas, for example the Mawas and Sebangau peat swamp forest area. This methodology of radar monitoring system may have the potential to become the core system for 'fast illegal logging response' within the Indonesian MOF.

    The implementation of the SAR monitoring for the Indonesian MOF is speeding up the ongoing decentralization policy. Recommendations are offered here to the Indonesian MOF, particularly for local authorities to enhance their capability in providing fast, accurate, and reliable information on forest condition. This capability will ensure the sustainability of the remaining tropical rain forest in the country.
    De dood in het bos
    Ouden, J. den - \ 2006
    Vakblad Natuur Bos Landschap 3 (2006). - ISSN 1572-7610 - p. 24 - 27.
    bosbedrijfsvoering - bosbranden - begrazing - mortaliteit - forest management - forest fires - grazing - mortality
    Verslag van twee bijeenkomsten van de Koninklijke Nederlandse Bosbouw Vereniging
    Fire ecology of Scots pine in Northwest Europe
    Hille, M.G. - \ 2006
    Wageningen University. Promotor(en): Frits Mohren; J.G. Goldammer. - [S.l. ] : S.n. - ISBN 9789085042839 - 179
    pinus sylvestris - brandecologie - bosbranden - biodiversiteit - bosecologie - plantensuccessie - europa - noordwest-europa - pinus sylvestris - fire ecology - forest fires - biodiversity - forest ecology - plant succession - europe - northwestern europe

    Keywords: biodiversity, fire ecology, fuel modelling, succession, tree regeneration

    In this thesis the ecological consequences of forest fire are studied in North-west European Scots pine {Pinus sylvestris) forests. The focus is on post-fire succession, and the factors and mechanisms that influence the successional pathways after fire. Fuel load and fuel moisture determine the intensity of forest fire and thus the degree of humus consumption. In a controlled laboratory' experiment humus consumption was determined for different moisture levels. Experimental fires showed evidence that variation in precipitation throughfall causes spatial variation in humus consumption in the stand through differences in humus moisture with respect to tree crowns. Humus consumption influences tree mortality, growth of remaining trees and re-colonization. Surface fires in Scots pine plantations caused a partial reduction of the litter and humus layers and a high mortality in the smaller trees. Reduction in radial growth after surface fire was variable, and was less in large diameter trees and in trees that experienced less humus consumption around their stem bases. Experimental burning of the humus layer showed that increased removal of organic material by fire resulted in an increase in seedling numbers. Earlier studies have suggested that the charcoal produced by fire improves germination conditions by absorbing phytotoxins produced by ericaceous species. All such studies have used activated carbon as a standardized model for charcoal. Bioassays with pine seeds in aqueous extracts of Vaccinium myrtillus and Calluna vulgaris showed toxic effects of the two species, but charcoal reduced toxicity less than activated carbon. Therefore, those previous studies have overestimated the effect of charcoal on germination, likely because of the considerably higher active surface area of activated carbon. The post-fire tree cohort after severe but small-scaled fires in Scots pine stands mainly consisted of Scots pine, but also birch and aspen. Compared to succession after other disturbance types in Scots pine stands, such as windthrow or soil scarification, seedling numbers are higher after small-scale fires by a magnitude often.

    Based on the good regeneration and for the purpose of fuel load reduction in areas with increased fire hazard, the prescribed burning of Scots pine stands should be reconsidered. Controlled forest fires could be used as an additional silvicultural technique to regenerate and transform single-species pine stands into mixed and more natural forests.

    Effecten van brand in een voedselarm dennenbos
    Kemmers, R.H. ; Dirkse, G.M. ; Mekkink, P. - \ 2005
    Vakblad Natuur Bos Landschap 2 (2005)3. - ISSN 1572-7610 - p. 6 - 10.
    naaldbossen - zandgronden - bosbranden - vegetatie - bodemchemie - nitraten - coniferous forests - sandy soils - forest fires - vegetation - soil chemistry - nitrates
    Door atmosferische stikstofdepositie zijn veel dennenbossen van de arme zandgronden vermest en in hun successie verstoord. Bij Kootwijk is in een voedselarm dennenbos onderzocht of de overmaat aan stikstof die in de strooisellaag lag opgeslagen door brand kan worden teruggedrongen en de bosontwikkeling zo kan worden teruggezet naar een voedselarme pionierfase. Op grond van de resultaten lijkt het twijfelachting dat brand effectief is als maatregel tegen vermesting. Hoofdlijnen uit Alterra rapport 1028; gevolgd door de visie van de beheerder (Staatsbosbeheer) in de persoon van Klein Lebbink
    Effecten van brand op bodem en vegetatie in dennenbossen van voedselarme zandgronden bij Kootwijk
    Kemmers, R.H. ; Dirkse, G.M. ; Hille, M.G. ; Mekkink, P. - \ 2005
    Wageningen : Alterra (Alterra-rapport 1028) - 57
    naaldbossen - bossen - verbranden - bodem - vegetatie - zandgronden - bosbranden - stikstof - verrijking - natuurgebieden - veluwe - gelderland - coniferous forests - forests - burning - soil - vegetation - sandy soils - forest fires - nitrogen - enrichment - natural areas - veluwe - gelderland
    Door atmosferische stikstofdepositie zijn veel bossen van de arme zandgronden vermest en in hun verdere successie verstoord. In een voedselarm dennenbos op zandgrond is onderzocht of door brand de overmaat aan stikstof die in de strooisellaag ligt opgeslagen kan worden teruggedrongen en de bosontwikkeling kan worden teruggezet naar een voedselarme pionierfase. Het onderzoek werd uitgevoerd bij Kootwijk waar in 1995 een bosbrand woedde. De vegetatie- en bodemkundige toestand van voor de brand, één en negen jaar na de brand werd geanalyseerd. Een belangrijke conclusie is dat brand eerder tot een verrijking van de bodem leidt dan tot een verschraling. Door brand vindt een verplaatsing van elementen van ectorganische naar endorganische horizonten plaats. Weliswaar verdwijnt er in zijn totaliteit stikstof, maar direct na de brand is de bodem sterk verrijkt met kalium, ammonium en fosfaat en in zuurgraad gedaald. Bovendien wordt het beschikbaar gekomen ammonium door micro-organismen vastgelegd in organische stof wat daardoor een rijk karakter krijgt. Dit effect is negen jaar na de brand nog steeds aanwezig. Het laten staan van de necromassa na de brand, zoals in Kootwijk plaatsvond, draagt niet bij aan het terugzetten van de vegetatiesuccessie naar een initieel schraal stadium, maar wel aan de diversiteit van bodemeigenschappen
    Dipterocarpaceae: forest fires and forest recovery
    Priadjati, A. - \ 2002
    Wageningen University. Promotor(en): R.A.A. Oldeman; J. Soedarsono; S.B.J. Menken. - Wageningen : Tropenbos International - ISBN 9789058087539 - 214
    dipterocarpaceae - bosbranden - verjonging - effecten - branden - shorea leprosula - milieufactoren - indonesië - dipterocarpaceae - forest fires - regeneration - effects - fires - shorea leprosula - environmental factors - indonesia

    One of the serious problems Indonesia is facing today is deforestation. Forests have been playing a very important role in Indonesia as the main natural resources for the economic growth of the country. Large areas of tropical forests, worldwide considered to be among the richest in plant diversity, have been lost in recent years mainly due to inappropriate logging, illegal logging, shifting cultivation, and forest fires. The negative repercussions of these activities are felt from an economical as well as from an ecological point of view.

    Time and again, Indonesia has experienced severe droughts often resulting in large forest fires. The fires used to occur only sporadically but now occur regularly every approx. 4 years in the area, with the largest and most destructive ones so far taking place in 1997-98. This climatic phenomenon was linked to a particularly pronounced El Niño Southern-Oscillation (ENSO), combined with numerous fires closely connected with human activities.

    'Dipterocarpaceae: Forest fires and forest recovery' discusses a comprehensive ecological understanding of fires, an overview of forest dynamics after fires, and the restoration strategies of the forest. Planting materials are reviewed in terms of their genetic diversity and their growth in different soil substrates, with various mycorrhizal inoculations and levels of light. The present publication is the last in a series adding information to the earlier projects conducted by Smits (1994), Yasman (1995), Hatta (1999) and Omon (2002).

    Microclimatic conditions change considerably after forest fires. The burned forest was characterized by elevated levels of light intensity and heat, and significantly reduced levels of humidity. After the fires, the natural dynamics of forest, in terms of regeneration of plants and butterfly communities, was set back to an earlier development phase where there were no more trees, only 2.5% of saplings survived and all saplings shorter than 5 m died. The butterfly community in the burned area had high densities of pioneer species associated with disturbed habitats. Burning caused a significant shift in the forest butterfly community. There was a highly significant variation in sapling and seedling density, diameter, and species richness between burned and unburned forest. Even though sapling height was significantly greater in burned than in unburned forest, there was no significant difference between their growth in both forests. The growth of both saplings and seedlings was completely unaffected by any edge effect in both forest types. The species richness, density and height of seedlings were significantly greater in unburned forest but their growth was significantly greater in burned forest. The diverse seedling community of unburned forest was replaced by a species-poor community of pioneers dominated by Euphorbiaceae.

    Dipterocarp forests can recover from fire impact if the damage is not too extensive and the fires are not recurrent, but their natural recovery is too slow to make it economically interesting, and therefore foresters try to restore the desired state of high forest as soon as possible. Their measures are based on the fact that similar microclimatic conditions in both forest types were reached within two years, so assisted recovery can be implemented soon in the burned area by introducing valuable climax tree species i.e dipterocarp species, before they would arrive spontaneously.

    Such operations require seedlings. Key issues for the management of dipterocarp stock plants in the nurseries included genetic diversity of the seedlings, choice and preparation of appropriate potting mixes, species-soil original matching, nursery hygiene and mycorrhizal inoculation. Cuttings grown in sandy loam showed a stronger and faster growth than the cuttings in sandy clay loam and loam. The higher sand fraction in the soil provided a good aeration for mycorrhizae and plants roots. Pasteurised soil media increased the growth of seedlings in the nursery. It is assumed that composition, acidity, moisture content and heat of the rooting media can be combined in a treatment optimising the conditions for both root development and root colonisation by fungi, thus increasing the quality and quantity of seedlings produced. It was found that interactions between so many factors lead to a highly complex situation, far from easy to control.

    S. leprosula proved to be very homogeneous as expressed from the similarities in frequencies of the band patterns. The similarity was relatively high between eastern, central and western Kalimantan populations but the nearer the geographic distance the more similar the populations.

    The initial inoculation supported S. leprosula to start growing in the greenhouse. In the established dipterocarp nursery, the spores of mycorrhizal fungi inoculated seedlings easily and freely. In 15 months in the greenhouse, all seedlings were colonised by these mycorrhizal weed fungi. Laccaria sp. was the most common one, followed by Thelephora sp. , Riessiella sp. and Inocybe sp . After 12 months in the field, the species composition of mycorrhizal fungi involved in root colonisation changed again. Inocybe sp . was still there, with two new other species being most abundant, namely Amanita sp. and Scleroderma sp. Even though the growth of S. leprosula seedlings in the nursery was supported by initial inoculation, in the field, no initial inoculation seedlings showed a stronger growth because they benefited more from the late stage fungi infecting the plants at the planting location.

    When dipterocarps are used, the key to success for a dipterocarp planting is species choice and light control. Selecting species suited to the local soil and site conditions is essential. Light control should correspond to the light requirements of a species during its growing stages, so planting methods should reflect site conditions and growth characteristics of the species. S. leprosula is a light-demanding species at the early stage, 60 to 73% (relative light intensity) for seedlings and 74 to 100% for saplings.

    The assisted recovery of pure Imperata cylindrica areas after fires is accelerated using mixed plantations composed of indigenous fast-growing pioneer tree species, i.e Peronema canescens that offer suitable conditions for the establishment of indigenous dipterocarp species. In circumstances without stress by fire, a young P. canescens tree has a well-developed monopodial trunk with a light canopy so that the light intensity under this species is very high or not much lower than in the open site. This shade condition (semi-closed) is not very suitable for S. leprosula seedlings when under-planted under this species. The capacity of P. canescens after fires to reiterate abundantly ('traumatic reiteration') and converge architecturally from Scarrone's model to a physiognomy resembling Leeuwenberg's model provided more favourable environmental conditions for S. leprosula to grow under the canopy of these trees (closed stand). Within almost three years, S. leprosula saplings in a closed stand and in a semi-open area reached a height of 281 to 283 cm and a diameter of 33 to 34 mm, whereas in the open area and under the semi-closed canopy of. P. canescens they were only 165 to 193 cm high and 22 to 27 mm in diameter.

    Long-term survival of a species depends on its ability to adapt to environmental change. Adaptability is a two-sided process. It rests on the optimal match between a genotype (organism) and its direct environment (ecosystem patch or 'eco-unit'). It is important to understand the reaction of the plants, so as to select genotypes adapted and adaptable to environmental stress in new environments. For this reason, next to the taxonomical data of S. leprosula , the architectural model and its reiteration are also described in this book.

    In Chapter 7 an overview is provided of the fire and forest regeneration issues with special reference to the Dipterocarpaceae and Shorea leprosula . Much practical information is provided on conditions for a successful regeneration of Dipterocarpaceae. It is concluded that the Dipterocarpaceae have become a threatened plant family and that safeguarding the genetic diversity of Shorea leprosula is highly urgent. If Dipterocarpaceae are to survive, the issue of fires must be resolved and dealt with.

    ENVISAT forest monitoring Indonesia
    Hoekman, D.H. ; Vissers, M.A.M. ; Sugardiman, R.A. ; Vargas, J. - \ 2002
    The RADARSAT International (RSI) RADARSAT-2 e-Newsletter 2 (2002)7. - p. 68 - 68.
    remote sensing - radar - tropische regenbossen - geografische informatiesystemen - landclassificatie - vegetatie - bosbranden - monitoring - kalimantan - indonesië - remote sensing - radar - tropical rain forests - geographical information systems - land classification - vegetation - forest fires - monitoring - kalimantan - indonesia
    To support the introduction of operational radar forest monitoring systems in Indonesian a demonstration is executed at the Tropenbos study area in East-Kalimantan. Interest focuses on fulfilling information needs relating to land cover change, fire risk and fire damage monitoring, with main emphasis on early detection.
    Advies over mogelijke activiteiten na de grote brand van juli 2000 : missie naar Samos, Griekenland 08-13 januari 2001
    Hillegers, P.J.M. - \ 2001
    Wageningen : Alterra - 16
    branden - bosbranden - voorkomen van branden - herstel - kennis - bosbedrijfsvoering - griekenland - bosbrand - landschapsecologie - multifunctioneel landgebruik - toerisme - Samos - fires - forest fires - fire prevention - rehabilitation - knowledge - forest management - greece - Samos
    Op Samos woedde zomer 2000 een grote brand, die een grote omvang kreeg door een droge tijd, een optredende hittegolf en een krachtige wind. Nederland was negatief betrokken bij deze brand, omdat het het enige land was, dat een negatief reisadvies afgaf voor toeristen. Diplomatieke bemiddeling resulteerde in een behulpzame missie om aanleiding en methodologie bij bosbranden en de voorkoming ervan aan een nader onderzoek te onderwerpen. Multifunctioneel landgebruik is een optie, de combinatie van recreatie, landbouw, veeteelt en bosbouw evenzo. Daarnaast is voor plattelandsontwikkeling locale participatie en samenwerking van belang
    Effecten van brand in bos op arme zandgronden
    Meijer zu Schlochtern, M. ; Koop, H.G.J.M. - \ 2000
    Wageningen : Alterra (Alterra-rapport 160) - 93
    bossen - bosbranden - brandgevolgen - brandecologie - vegetatie - schimmels - zandgronden - nederland - brandgedrag - forests - forest fires - fire effects - fire ecology - vegetation - fungi - sandy soils - netherlands - fire behaviour
    Het rapport doet verslag van een onderzoek naar de directe en indirecte effecten van brand in bos op arme zandgronden. Voor de directe effecten is op een brandvlakte nabij Kootwijk kort na de brand in kaart gebracht waar grond-, loop- of kronenvuur heeft gewoed. Er is een relatie gelegd met de bosstructuur en het ontstaan van de verschillende soorten brand. Er is tevens een relatie gelegd tussen de vijf verschillende intensiteiten, die op basis van vlamhoogte zijn onderscheiden, en de overleving van de bomen en struiken in verschillende hoogteklassen. De indirecte effecten zijn onderzocht door vegetatie te onderzoeken op brandvlaktes van verschillende ouderdom. Deze vegetatieontwikkeling laat zien dat na een korte periode van verrijking, een verarming van nutri%nten te zien is. Pioniersoorten koloniseren de brandvlaktes, waarbij grondbewonende korstmossen weer veelvuldig aanwezig zijn.
    Bosbranden
    Anonymous, - \ 1979
    Wageningen : Pudoc (Literatuurlijst / Centrum voor Landbouwpublikaties en Landbouwdocumentatie no. 4323)
    bibliografieën - bosschade - bosbranden - bibliographies - forest damage - forest fires
    Bosbranden en het gevaar voor Rhizina undulata
    Gremmen, J. - \ 1976
    Wageningen : De Dorschkamp (Bericht / Rijksinstituut voor Onderzoek in de Bos- en Landschapsbouw "De Dorschkamp" nr. 92)
    pezizomycotina - bosbouw - plantenziekteverwekkende schimmels - plantenziekteverwekkende bacteriën - bomen - bosbranden - bosschade - rhizina undulata - pezizomycotina - forestry - plant pathogenic fungi - plant pathogenic bacteria - trees - forest fires - forest damage - rhizina undulata
    Notities over terreinvoorbereiding voor herbebossing na bosbrand
    Kofman, P. - \ 1976
    Wageningen : De Dorschkamp (Bericht / Rijksinstituut voor Onderzoek in de Bos- en Landschapsbouw "De Dorschkamp" nr. 91)
    bosbouw - werkplanning - velling - seizoenen - bosbranden - bosschade - forestry - work planning - felling - seasons - forest fires - forest damage
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