Why elephant roam
Ngene, S.M. - \ 2010
University of Twente. Promotor(en): Andrew Skidmore; Herbert Prins; H.A.M.J. van Gils. - Enschede : University of Twente Faculty of Geo-Information and Earth Observation ITC - ISBN 9789061642909 - 195
loxodonta africana - geografische informatiesystemen - remote sensing - zoögeografie - geografische verdeling - beweging - menselijke activiteit - seizoenen - diergedrag - kenya - menselijke invloed - loxodonta africana - geographical information systems - remote sensing - zoogeography - geographical distribution - movement - human activity - seasons - animal behaviour - kenya - human impact
The expansion of human activities due to the increase in human population outside protected areas is reducing the range of elephant. This range reduction occurs when elephant habitats are cleared for more farms and settlements. This causes fragmentation of the elephant range, which changes the elephant’ distribution, movement patterns, intensity of occupancy, and speed of movement. The objectives of this study were to use GIS and remote sensing to identify the factors that influence the distribution, intensity of occupancy, and speed of movement of Marsabit elephant; to map and describe their wet and dry season range, intensity of occupancy, and speed of movement, as well as seasonal altitudinal movement in the fragmented mosaic of forest and savanna; to research the cost of humans sharing the environment with the elephant in areas adjacent to Marsabit Protected Area.
Species and structural diversity of church forests in a fragmented Ethiopian Highland landscape
Wassie Eshete, Alemayehu ; Sterck, F.J. ; Bongers, F. - \ 2010
Journal of Vegetation Science 21 (2010)5. - ISSN 1100-9233 - p. 938 - 948.
himalayan altitudinal gradient - tropical rain-forest - habitat fragmentation - montane forest - human impact - conservation - biodiversity - richness - disturbance - management
Question: Thousands of small isolated forest fragments remain around churches (“church forests”) in the almost completely deforested Ethiopian Highlands. We questioned how the forest structure and composition varied with altitude, forest area and human influence. Location: South Gondar, Amhara National Regional State, Northern Ethiopia. Methods: The structure and species composition was assessed for 810 plots in 28 church forests. All woody plants were inventoried, identified and measured (stem diameter) in seven to 56 10 m x 10-m plots per forest. Results: In total, 168 woody species were recorded, of which 160 were indigeneous. The basal area decreased with tree harvest intensity; understorey and middle-storey density (5 cm DBH trees) increased with altitude. The dominance of a small set of species increased with altitude and grazing intensity. Species richness decreased with altitude, mainly due to variation in the richness of the overstorey community. Moreover, species richness in the understorey decreased with grazing intensity. Conclusions: We show how tree harvesting intensity, grazing intensity and altitude contribute to observed variations in forest structure, composition and species richness. Species richness was, however, not related to forest area. Our study emphasizes the significant role played by the remaining church forests for conservation of woody plant species in North Ethiopian Highlands, and the need to protect these forests for plant species conservation purposes
Assessment of Ramsar site Lac Bonaire - June 2010
Debrot, A.O. ; Meesters, H.W.G. ; Slijkerman, D.M.E. - \ 2010
Yerseke : IMARES (Report / IMARES Wageningen UR nr. C066/10) - 31
natuurbescherming - beschermingsgebieden - mangroves - ecologisch herstel - menselijke invloed - nadelige gevolgen - bonaire - nature conservation - conservation areas - mangroves - ecological restoration - human impact - adverse effects - bonaire
Following a helpdesk question from the Dutch Ministry of Agriculture, Nature and Food Quality (LNV) concerning potential threats to the Ramsar Site, Lac Bonaire, the authors visited Lac Bay from 27-29 May 2010. The mangroves, seagrass beds and the reef, both inside and outside of the bay were visited, and we were generously helped by many people on the island, including STINAPA Bonaire, DROB, STCB, and CIEE. In this study we review the main issues, recommend studies, and propose various pilot projects and solutions.
Disturbance-effect relationships applied in an integral Ecological Risk Analysis for the human use of the North Sea
Karman, C.C. ; Slijkerman, D.M.E. ; Tamis, J.E. - \ 2009
Den Helder : IMARES (Report / Wageningen IMARES no. C011/09) - 31
ecosystemen - noordzee - mariene gebieden - menselijke invloed - aquatische ecosystemen - ecosystems - north sea - marine areas - human impact - aquatic ecosystems
The relationship between the intensity of seven types of human based disturbances and their resulting effects on survival and reproduction of 30+ species were described as a function of increased mortality or reduced reproduction in the report of Jak et al 2000. The numerical values of the parameters in these functions were, as far as possible, estimated on the basis of data from literature, dealing with the sensitivity of the considered species, or otherwise of related species or biota in general, for the regarded disturbance
BioScore: A tool to assess the impacts of European Community policies on Europe's biodiversity
Delbaere, B. ; Nieto Serradilla, A. ; Snethlage, M. ; Alkemade, R. ; Boitani, L. ; Eggers, J. ; Falcucci, A. ; Framstad, E. ; Heer, M. de; Hennekens, S.M. ; Kemitzoglou, D. ; Knegt, B. de; Knijf, G. de; Louette, G. ; Maes, D. ; Maiorano, L. ; Nagy, S. ; Ozinga, W.A. ; Schaminée, J.H.J. ; Tol, S. van; Tröltzsch, K. - \ 2009
Tilburg : ECNC - ISBN 9789076762289 - 92
biodiversiteit - flora - fauna - impact - beleid - beoordeling - europa - menselijke invloed - ecologische beoordeling - biodiversity - flora - fauna - impact - policy - assessment - european union countries - human impact - ecological assessment
BioScore offers a European biodiversity impact assessment tool. The tool contains indicator values on the ecological preferences of more than 1000 species of birds, mammals, amphibians, reptiles, fish, butterflies, dragonflies, aquatic macro-invertebrates and vascular plants. These values are linked to policy-related pressures and environmental variables.
A safe operating space for humanity
Rockström, J. ; Steffen, W. ; Noone, K. ; Scheffer, M. - \ 2009
Nature 461 (2009). - ISSN 0028-0836 - p. 472 - 475.
social-ecological systems - human impact - biodiversity - climate - perspective - resilience - consequences - ecosystems - phosphorus - shifts
New approach proposed for defining preconditions for human development Crossing certain biophysical thresholds could have disastrous consequences for humanity Three of nine interlinked planetary boundaries have already been overstepped
Gebiedsbescherming Noordzee : habitattypen, instandhoudingdoelen en beheermaatregelen
Lindeboom, H.J. ; Witbaard, R. ; Bos, O.G. ; Meesters, H.W.G. - \ 2008
Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-werkdocument 114) - 45
noordzee - habitats - bescherming - natuurbescherming - mariene ecologie - milieubeleid - nederland - menselijke invloed - north sea - habitats - protection - nature conservation - marine ecology - environmental policy - netherlands - human impact
In het Integraal Beheerplan Noordzee 2015 is een aantal gebieden aangewezen als potentieel te beschermen gebieden. Voor deze gebieden dienen instandhoudingsdoelen te worden opgesteld. Echter, door de grote variatie van het mariene ecosysteem en het feit dat grote delen van de Noordzee al gedurende decennia enorm door menselijke activiteiten zijn beïnvloed, kleven hier een aantal problemen aan. In dit werkdocument worden deze nader uiteengezet en worden bouwstenen voor mogelijke oplossingen aangedragen. Het werkdocument bevat een korte beschrijving van de (eventueel) te beschermen gebieden; een overzicht van natuurlijke en door de mens gecreëerde habitattypen; een beschrijving van de natuurlijke fluctuaties van het mariene ecosysteem en de mogelijke consequenties voor aanwijzing en beheer van te beschermen gebieden. Gezien de grote variatie van het systeem is het vaststellen van instandhoudingdoelen die gebaseerd zijn op het voorkomen van soorten en het daarna handhaven van zulke doelen in een dergelijk sterk wisselend systeem waarschijnlijk niet efficiënt. Voorgesteld wordt om beheersdoelen of managementdoelen te definiëren uitgaande van de beschreven habitatindeling. Het beheer zou gericht moeten zijn op de menselijke invloeden op de verschillende habitattypen waardoor men een rigide nastreven van mogelijk onbereikbare doelen voorkomt.
De veranderlijke zee in het Antropoceen : over regime shifts, menselijk gebruik en bescherming
Lindeboom, H.J. - \ 2008
Wageningen : Wageningen Universiteit, Wageningen UR - ISBN 9789085852667 - 26
mariene ecologie - visserij - duurzaamheid (sustainability) - bescherming - menselijke invloed - openbare redes - marine ecology - fisheries - sustainability - protection - human impact - public speeches
De beleving van grote wateren : de invloed van een aaantal man-made elementen onderzocht
Vries, S. de; Boer, T.A. de; Goossen, C.M. ; Wulp, N.Y. van der - \ 2008
Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-rapport 64) - 98
mariene gebieden - meren - perceptie - gebouwen - jachthavens - turbines - cyanobacteriën - kustgebieden - omgevingspsychologie - menselijke invloed - marine areas - lakes - perception - buildings - marinas - turbines - cyanobacteria - coastal areas - environmental psychology - human impact
De invloed van boorplatforms, windturbines, hoogbouw aan de kust, jachthavens en vooroevers op de beleving van grote wateren is onderzocht. Als enige niet man-made element is blauwalg meegenomen. De beleving beperkt zich hier tot de waardering voor de visuele component. Door middel van (gemonteerde) foto’s kreeg de ene groep de situatie met het element voorgelegd, een andere zonder. Ongeveer 2300 leden van een consumentenpanel, verdeeld over vier groepen, namen via het internet deel aan het onderzoek. Elke groep beoordeelde 30 foto’s. Boorplatforms hebben de grootste negatieve impact, gevolgd door windturbines en daarna hoogbouw. Vooroevers hebben als enige gemiddeld een (licht) positieve impact. De negatieve impact bleek groter naarmate de situatie zonder element aantrekkelijker werd gevonden. Systematische variaties van de verschijningsvorm van een element lieten zien dat de ‘stap’ van niet naar wel aanwezig zijn het grootste effect opleverde: de negatieve impact nam slechts gering toe met de variabelen nabijheid, grootte en aantal van het element. Trefwoorden: belevingswaarde, grote wateren, boorplatforms, windturbines, hoogbouw, jachthavens, vooroevers, blauwalg
Impact of human activities on water level and clarity and underwater light climate of Vallisneria spiralis L. in Poyan Lake, China
Wu, G. - \ 2008
Wageningen University. Promotor(en): Andrew Skidmore; Herbert Prins, co-promotor(en): J. de Leeuw. - [S.l.] : S.n. - ISBN 9789085049074 - 119
meren - china - water - oppervlaktewater - waterkwaliteit - watervogels - waterplanten - lichtsterkte - vallisneria spiralis - troebelheid - voedselplanten - groei - remote sensing - oppervlaktewaterkwaliteit - waterstand - aquatische ecosystemen - menselijke invloed - lakes - china - water - surface water - water quality - waterfowl - aquatic plants - light intensity - vallisneria spiralis - turbidity - food plants - growth - remote sensing - surface water quality - water level - aquatic ecosystems - human impact
Almost 95% of the world population of Siberian crane (Grus leucogeranus) winter in Poyang Lake, China. Here they forage on the tubers of the submerged aquatic macrophyte Vallisneria spiralis L. The growth and production of V. spiralis are regulated by the local hydrology, which might also be influenced by the changed hydrology of the Yangtze River induced by engineering projects. This thesis investigated the impact of dredging activities in the northern Poyang Lake and the Three Gorges Dam in the Yangtze River on the water turbidity and water level of Poyang Lake, analyzed how these hydrological changes influenced the underwater light climate of V. spiralis, and discussed their potential impacts on the growth and productivity of V. spiralis and further on the food habitat of Siberian crane in Poyang Lake. The principal results obtained can be summarized as follows:
(1) Moderate resolution imaging spectroradiometer (MODIS) and Landsat thematic mapper (TM) images were compared for mapping the tempo-spatial dynamics of water clarity. Two multiple regression models including the blue and red bands of Landsat TM and MODIS respectively explained 83% and 88% of the variation of the natural logarithm of Secchi disk depth. On the basis of the comparison of water clarity predicted from Landsat TM and MODIS data as well as the advantages and contras of both sensors, it is concluded that MODIS offers the possibility to monitor the dynamics of water clarity more regularly and cheaply in relatively big and frequently cloud covered lakes like Poyang Lake.
(2) The performance of the various Landsat TM bands for detecting dredging ships was explored in the turbid water of the northern Poyang Lake. The result revealed that the TM bands 1 to 4 had limitation especially in turbid water, while bands 5 and 7 better discriminated vessels from surrounding waters. Therefore, it is recommended using the mid-infrared bands of Landsat TM for operational ship monitoring in turbid water.
(3) The possibility to strengthen inference of dredging impact while simultaneously monitoring vessels and water turbidity with remote sensing techniques was investigated in the northern Poyang Lake. Time-series MODIS images revealed a significant increase in water turbidity from 2001 onwards, while Landsat TM image analysis indicated a simultaneous increase in the number of vessels. Regression analysis further showed a highly significant positive relation (R2 = 0.92) between water turbidity and vessel number. On the basis of discussion of ship-related resuspension, final destinations of vessels and coincidence of vessel clusters with irregular dented patterns and turbid plume development, it is confirmed that dredging caused the increase in water turbidity. Therefore, it is concluded that simultaneously monitoring water turbidity and vessels enhanced the strength of evidence in remotely sensed dredging impact assessments.
(4) Three extrapolation and interpolation methods were compared for predicting daily photosynthetically active radiation reaching the earth surface over the Poyang Lake national nature reserve. The result revealed that the triangulated irregular network (TIN) and inverse distance weighted (IDW)-based interpolation method produced more reliable result than the extrapolation methods.
(5) The photosynthetically active radiation reaching the top of V. spiralis (PARlc) in Lake Dahuchi from 1998 to 2006 was modelled. The results revealed significant between year differences in PARtc, which were determined primarily by fluctuation in water level. Six years of Secchi disk depth records revealed seasonal switching of the lake from turbid at low water level in autumn, winter and spring to clear at high water level in summer. The highest PARtc occurred at intermediate water levels, which were reached when the Yangtze River forces Lake Dahuchi out of its turbid state in spring. The operation of the Three Gorges Dam, which will increase water level of Yangtze River from May to June may force Lake Dahuchi out of its turbid state earlier and increase the light intensity reaching the canopy and the production of V spiralis. It is concluded that the operation of the Three Gorges Dam might at the short term increase the light regime and productivity of V. spiralis and possibly affect the food habitat of Siberian crane in Poyang Lake.
(6) A conceptual framework to integrate a simulation model of plant biomass for V. spiralis with remote sensing and a geographical information system was introduced. It is expected that the system, once implemented, could contribute to evaluate the impact of possible hydrological changes on the growth and productivity of V. spiralis, and assess whether tuber feeding bird populations are constrained by the regional availability of food resources in Lake Poyang.
It is anticipated that these results provide a basis for the future research and necessary information for decision-making that need to be made by the responsible authorities to decide how to rationally manage this unique lake ecosystem.
Low flow and drought studies : the Northern European (NE) FRIEND experience
Tallaksen, L. ; Demuth, S. ; Lanen, H.A.J. van - \ 2007
In: Climatic and anthropogenic impacts on the variability of water resources. - Paris : Unesco - p. 99 - 106.
watervoorraden - klimaat - klimaatverandering - conferenties - menselijke invloed - water resources - climate - climatic change - conferences - human impact
Invloed van varkenshouder op weerstand varkens onderzocht
Mul, M.F. - \ 2006
V-focus 3 (2006). - ISSN 1574-1575 - p. 40 - 41.
varkenshouderij - varkens - weerstand - ziekteresistentie - kennisniveau - agrarische bedrijfsvoering - menselijke invloed - pig farming - pigs - resistance - disease resistance - knowledge level - farm management - human impact
In juni 2005 startte ASG een praktijkproef met 35 varkenshouders in Overijssel, Gelderland, Noord-Brabant en Limburg, waarbij wordt onderzocht of een hoger kennisniveau bij de varkenshouder leidt tot een verbetering van de weerstand van z'n dieren. Er is sprake van kennisuitwisseling tussen varkenshouders, onderzoekers en dierenartsen samen
Wadden Sea Quality Status report 2004
Essink, K. ; Dettmann, C. ; Frake, H. ; Laursen, K. ; Lüerssen, G. ; Wiersinga, W.A. - \ 2005
Wilhelmshaven, Germany : Common Wadden Sea Secretariat (Wadden Sea ecosystem No. 19) - 359
ecologie - mariene ecologie - ecosystemen - menselijke invloed - aquatische ecosystemen - waddenzee - aquatische ecologie - ecology - marine ecology - ecosystems - human impact - aquatic ecosystems - wadden sea - aquatic ecology
The report consists of 13 chapters containing basic information on human activities in the Wadden Sea and on physico-chemical and ecological conditions. Chapter 14 gives a synthesis of ecosystem developments. In Chapter 15, an evaluation is given of the Targets of the Wadden Sea Plan.
Sources and delivery of carbon, nitrogen, and phosphorus to the coastal zone: An overview of global Nutrient Export from Watersheds (NEWS) models and their application
Seitzinger, S.P. ; Harrison, J.A. ; Dumont, E.L. ; Beusen, A.H.W. ; Bouwman, A.F. - \ 2005
Global Biogeochemical Cycles 19 (2005). - ISSN 0886-6236 - p. GB4S01 - GB4S01.
marine ecosystems - drainage network - river estuary - world rivers - human impact - limitation - eutrophication - plankton - systems - inputs
An overview of the first spatially explicit, multielement (N, P, and C), multiform (dissolved inorganic: DIN, DIP; dissolved organic: DOC, DON, DOP; and particulate: POC, PN, PP) predictive model system of river nutrient export from watersheds (Global Nutrient Export from Watersheds (NEWS)) is presented. NEWS models estimate export from 5761 watersheds globally as a function of land use, nutrient inputs, hydrology, and other factors; regional and global scale patterns as of 1995 are presented here. Watershed sources and their relative magnitudes differ by element and form. For example, anthropogenic sources dominate the export of DIN and DIP at the global scale, although their anthropogenic sources differ significantly (diffuse and point, respectively). Natural sources dominate DON and DOP export globally, although diffuse anthropogenic sources dominate in several regions in Asia, Europe and N. America. "Hot spots" where yield (kg km-2 yr-1) is high for several elements and forms were identified, including parts of Indonesia, Japan, southern Asia, and Central America, due to anthropogenic N and P inputs in some regions and high water runoff in others. NEWS models provide a tool to examine past, current and future river export of nutrients, and how humans might impact element ratios and forms, and thereby affect estuaries and coastal seas.
Disturbance, diversity and distributions in Central African rain forest
Gemerden, B.S. van - \ 2004
Wageningen University. Promotor(en): A.M. Cleef; Marc Sosef, co-promotor(en): H. Olff. - - 199
tropical rain forests - biodiversity - rehabilitation - plant succession - conservation - forest ecology - logging - shifting cultivation - central africa - human impact - disturbance - tropische regenbossen - biodiversiteit - herstel - plantensuccessie - conservering - bosecologie - houtkap - zwerflandbouw - centraal-afrika - menselijke invloed - verstoring
The aim of this study is to gain insight in the impact of human land use on plant community composition, diversity and levels of endemism in Central African rain forest. Human disturbance in this region is causing large-scale habitat degradation. The two most widespread forms of land use are selective logging and shifting cultivation. Assessment of the long-term effects of these land uses on plant species composition will provide elements for the identification of effective conservation measures and sustainable forms of forest use.Disturbances are relatively discrete events in time that cause high mortality of biomass and change the structure of populations, communities or ecosystems. Individual plants and species differ in their ability to claim the previously utilised space and resources, and therefore disturbance events may cause (temporary) shifts in species composition and diversity. In large parts of the African rain forest biome, the most important natural disturbance regime is gap-phase dynamics in which relatively small canopy openings are made by falling branches or trees. Larger-scale disturbances such as landslides, volcanic activity and large-scale river dynamics, have been extremely rare during the last millennia. Therefore, the present set of species is likely to be adapted to disturbance regimes characterised by frequent small-scale disturbances. Analogous to gap-phase dynamics, human land use can be considered as a disturbance. However, human induced disturbances are generally larger, more frequent and more severe. As a result, human land use may have long-term impacts on plant species composition and diversity.The fieldwork for this thesis was conducted in the main research site of the Tropenbos-Cameroon Programme; an area of 2000 km 2 of forestland in South Cameroon Vegetation was sampled in old growth forest, logging gaps of 5, 14 and 27 years old, and in abandoned shifting cultivation fields of 10-20, 30-40 and 50-60 years old. Within plots, all terrestrial vascular plants (including all growth forms) were recorded. In total 10.1 ha was surveyed allowing the detailed analysis of human impact on full plant species composition. Much effort was devoted to plant identification and in total some 11 000 herbarium vouchers were collected, processed and sent to specialists for identification. Voucher material was stored in theNationaalHerbarium Nederland - WageningenUniversity branch and in the IRAD/TropenbosField Herbarium inKribi. Some 75% of the plants in the survey identified to species level and an additional 20% was systematically categorised asmorphospecies. In total 1264 species were identified to species level. These included 261 species with ranges restricted to Lower Guinea (South Nigeria - Gabon) of which 51 are confined to the rain forest region of Cameroon.Tropical rain forests are often regarded as being undisturbed by humans. In Chapter 2, we analyse the disturbance history of 16 ha of structurally complex and species-rich 'old growth' rain forest (data collected by forestry research project of theTropenbos-Cameroon Programme). The recruitment preference of tree species along a disturbance gradient, ranging from shifting cultivation fields, to canopy gaps and old growth forest, was compared to present-day tree species composition. In nine plots out of 16, older (larger) trees preferred shifting cultivation fields for recruitment while younger trees recruited in small canopy gaps and under closed canopy. These results indicate that these plots once experienced a disturbance regime that included larger-scale disturbances. Combined, the pattern of disturbed and undisturbed plots, the high frequency of charcoal in the forest soil and anthropological data strongly suggest that humans caused these disturbances. The estimated date of these disturbances is 300-400 years ago. Surprisingly, species richness at larger scales was found to be lower in historically disturbed sites compared to undisturbed sites. Therefore, present-day species composition and diversity of old growth forests still reflects historical human impacts.Outside protected areas, forests are subject to logging and shifting cultivation and secondary forests are therefore becoming important in many Central African landscapes. Chapter 3 examines the potential of secondary vegetation to contribute to biodiversity conservation. The results indicate that vegetation recovery in logging plots and abandoned shifting cultivation fields is relatively quick, and in most aspects surprisingly complete. A notable exception is the poor recovery of endemics in shifting cultivation fields. We found that even after 60 years the proportion of endemic species was still significantly lower than in old growth forest. In light of the fast recovery of all other vegetation characteristics (including species richness and floristic composition), we conclude that secondary vegetation can contribute biodiversity conservation e.g. as buffer zones around protected areas.In Chapter 4, we analyse the relative importance of local and regional processes for structuring species composition during succession. Local processes refer to the ability of species to compete successfully with other species and avoid predation and pathogen attack. Regional processes refer to dispersal and colonisation. Both processes have been suggested to explain the typically high species richness in tropical rain forests. Our results indicate that local processes are especially important during the early stages of succession, whereas regional processes are especially important during the later stages. However, large differences were observed between different species groups. Regional processes mainly governed composition of large tree species (maximum height ≥ 15 m). A similar but smaller effect was observed in small tree species (3-15 m) and shrub species. Local processes structured composition of terrestrial herb species. In general, woody and non-woody climbers were widely distributed generalists with a very similar set of species occurring in all landscape mosaics and in all succession stages. The differences between species groups implies that effective conservation management requires insight in the importance of local and regional processes for the recruitment of target species (e.g. endemic species). A blanket conservation treatment for all species is unlikely to address adequately the specific sensitivity of species with high conservation value to habitat quality and habitat fragmentation.The general lack of information on biodiversity patterns is a serious problem for conservation planning in most tropical rain forest regions. With ongoing habitat destruction, conservation priorities must be identified quickly. Therefore optimal use should be made of all currently available sources of information. However, direct comparison of results is problematic if assessment methods differ. In Chapter 5, we make a first attempt to reconcile different assessments by taking into account their methodological differences. The key factors affecting the general shape and position of the species-area curve found through partial sampling are (1) the total extent in which observations are made, (2) the spatial distribution of the observations, (3) the proportion of the total extent sampled, (4) the proportion of the individuals in the sampled area that was included in the survey, and (5) the proportion of the included individuals that was successfully identified. Through simulations, the effects of partial sampling of these factors on observed species richness was identified. To test the method, we compared four botanical surveys conducted in the same area of lowland old growth rain forest. The surveys included were (1) reconnaissance scale vegetation survey, (2) detailed botanical assessment (100% individuals), (3) incomplete botanical assessment (10% individuals), and (4) herbarium collections. Correcting for partial sampling and scaling the results to extent greatly increased the comparability between assessments. This first attempt to reconcile methodologically different surveys suggests that species -area relations can be reconstructed from incomplete sample data if the key characteristics of the methods can be statistically described. The study provides an outline for optimising the use of existing datasets in the evaluation of conservation needs in tropical rain forest areas.In Chapter 6, I present an overview of the main effects of human land use on plant diversity in Central African forest. Rain forests are highly dynamic on all spatial and temporal scales. Present-day species composition and diversity reflects their cumulativebiogeographicalhistory. Therefore both present-day and historical disturbance regimes should be considered to understand current patterns of diversity and to predict its responses to future disturbances. The biotic andabioticprocesses that influence diversity vary with the scale of organisation of biological and ecological systems (i.e. community, ecosystem, landscape,region). While human land use obviously disrupts local communities, the impact of humans is also evident on much larger scales. As a result of large-scale forest degradation, fragmentation and global climate change, species composition of most Central African rain forests is likely to undergo changes in the near future. Conservation management should aim at increasing the survival chances of endemic species and species with poor dispersal capacity. In light of the present ecological insights and the uncertainty of the upcoming climate changes, it seems wise to invest in large networks of protected areas. Moreover, it is unlikely that areas managed for timber production will be beneficial for the conservation of characteristic plant diversity unless damage control is rigid. The expected increase in seasonality in large parts of Central Africa, combined with forest fragmentation and canopy opening, is likely to increase the abundance of pioneer species while species of concern to conservation are likely to decline. To increase the effectiveness of conservation management, insight is required in the mechanisms that make species and forest systems vulnerable to human induced disturbances, including global climate change.
Lanen, H.A.J. van; Kasparek, L. ; Novicky, O. ; Querner, E.P. ; Fendeková, M. ; Kupczyk, E. - \ 2004
In: Hydrological drought. Processes and estimation methods for streamflow and groundwater / Tallaksen, L.M., van Lanen, H.A.J., Amsterdam : Elsevier (Developments in Water Science 48) - ISBN 9780444516886 - p. 347 - 410.
droogte - hydrologische factoren - menselijke invloed - drought - hydrological factors - human impact
Human activities can cause drought, which was not previously reported (man-induced hydrological drought). Groundwater abstractions for domestic and industrial use are a well-known example of such an environmental change
|Hunter and hunted
Broekhuizen, S. - \ 2003
Lutra 46 (2003)1. - ISSN 0024-7634 - p. 75 - 76.
vleesetende dieren - prooi - predator prooi verhoudingen - boekbesprekingen - menselijke invloed - carnivores - prey - predator prey relationships - book reviews - human impact
Bespreking van het nieuwste boek van Hans Kruuk (University Press Cambridge, 2002) over landroofdieren en de invloed die ze hebben op hun prooidiersoorten, inclusief de mens, en over de invloed die de mens heeft en heeft gehad op de landroofdieren
Recreatie en biodiversiteit in balans; een ruimtelijke benadering
Vos, C.C. ; Opdam, P.F.M. ; Pouwels, R. - \ 2003
Landschap : tijdschrift voor landschapsecologie en milieukunde 20 (2003)1. - ISSN 0169-6300 - p. 3 - 13.
openluchtrecreatie - natuurbescherming - fauna - populaties - vogels - monitoring - bedrijfsvoering - duinen - menselijke invloed - outdoor recreation - nature conservation - birds - fauna - populations - monitoring - management - dunes - human impact
In Nederland streeft men ernaar natuurgebieden zo veel mogelijk open te stellen voor recreatie. Recreatie kan echter een extra stressfactor betekenen voor kleine en versnipperde populaties. Dat kan de duurzame instandhouding van soorten in gevaar brengen. Het combineren van recreatie en natuur vraagt daarom om een goede balans. In dit artikel wordt een beleidsinstrument gepresenteerd waarmee de effecten van recreatie en de effectiviteit van recreatiezonering zijn verkend.
|Will reactivation of the Iron Rhine railroad decrease survival of badgers (Meles meles) in Meinweg National Park, the Netherlands
Grift, E.A. van der; Nieuwenhuizen, W. - \ 2002
Lutra 45 (2002)1. - ISSN 0024-7634 - p. 29 - 48.
dassen (zoogdieren) - meles meles - spoorwegen - railtransport - natuurbescherming - dierecologie - ecologie - populatie-ecologie - netwerkanalyse - nederland - netwerken - midden-limburg - menselijke invloed - dassen - fauna - infrastructuur - landschapsecologie - natuurgebied - populatiebiologie - spoorweg - versnippering - zoogdieren - Limburg - IJzeren Rijn - Meinweg - badgers - meles meles - railways - rail transport - nature conservation - animal ecology - ecology - population ecology - network analysis - netherlands - human impact - networks - midden-limburg - fauna
Met verschillende variaties is het effect van hergebruik van een goederenspoorlijn op de ontwikkeling van een dassenpopulatie in Midden-Limburg onderzocht
Van buiten word je beter : een essay over de relatie tussen natuur en gezondheid
Berg, A.E. van den; Berg, M.M.H.E. van den - \ 2001
Wageningen : Alterra - 55
natuurbescherming - perceptie - mens - geestelijke gezondheid - natuur - menselijke invloed - gezondheid - maatschappijwetenschap - omgevingspsychologie - nature conservation - perception - man - mental health - nature - human impact