Forest Types (forest + type)

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Forest Types

  • different forest type


  • Selected Abstracts


    Influence of Forest Type and Tree Species on Canopy-Dwelling Beetles in Budongo Forest, Uganda,

    BIOTROPICA, Issue 3 2000
    Thomas Wagner
    ABSTRACT Beetles were collected on 64 trees of four species (Cynometra alexandri C. H. Wright, Rinorea beniemis (Welwitsch ex Olivier) Kuntze, Teclea nobilis Delile, and Trichilia rubescens Olivier) in Budongo Forest, Uganda, using an insecticidal fogging technique. Selected tree species were abundant, taxonomically not closely related, and different in the shape of leaves, growth form, and size, with heights between 7 and 35 m. Trees were fogged in an old primary forest stand, in an area of secondary forest where selective logging was performed, and in a swamp forest. Eight conspecific trees per forest type were fogged. A total of 29,736 beetles were collected from all trees that could be assigned to 1433 (morpho)-species; 41.6 percent were singletons and 89.6 percent of species were found with less than ten individuals. Abundant beetle taxa included Latridiidae (N= 4093), Chrysomelidae (3952), Staphylinidae (2931), Apioninae (2621), and Curculionidae (2457). Most species-rich groups were Staphylinidae (N= 196 spp.), Curculionidae (189), and Chrysomelidae (148). Abundance increased in the order: primary < secondary < swamp forest. Due to the relatively high dominance of some species in the secondary forest, species richness increased in the order: secondary < primary < swamp forest. Beta diversity measures and factor analysis showed distinct differences among forest types but higher similarity of beetle communities on different tree species within one forest type. The taxonomic distribution of beetles in the secondary forest was more heterogeneous than in the primary forest. Analyses of the data revealed low host specificity even for phytophagous beetles, underlining the importance of habitat structure and chance effects on the spatial distribution of beetles in the canopy of Budongo Forest. [source]


    Methane and nitrous oxide fluxes of soils in pure and mixed stands of European beech and Norway spruce

    EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 5 2006
    W. Borken
    Summary Tree species can affect the sink and source strength of soils for atmospheric methane and nitrous oxide. Here we report soil methane (CH4) and nitrous oxide (N2O) fluxes of adjacent pure and mixed stands of beech and spruce at Solling, Germany. Mean CH4 uptake rates ranged between 18 and 48 ,g C m,2 hour,1 during 2.5 years and were about twice as great in both mixed and the pure beech stand as in the pure spruce stand. CH4 uptake was negatively correlated with the dry mass of the O horizon, suggesting that this diminishes the transport of atmospheric CH4 into the mineral soil. Mean N2O emission was rather small, ranging between 6 and 16 ,g N m,2 hour,1 in all stands. Forest type had a significant effect on N2O emission only in one mixed stand during the growing season. We removed the O horizon in additional plots to study its effect on gas fluxes over 1.5 years, but N2O emissions were not altered by this treatment. Surprisingly, CH4 uptake decreased in both mixed and the pure beech stands following the removal of the O horizon. The decrease in CH4 uptake coincided with an increase in the soil moisture content of the mineral soil. Hence, O horizons may maintain the gas diffusivity within the mineral soil by storing water which cannot penetrate into the mineral soil after rainfall. Our results indicate that conversion of beech forests to beech,spruce and pure spruce forests could decrease soil CH4 uptake, while the long-term effect on N2O emissions is expected to be rather small. [source]


    Assessing the relationship between forest types and canopy tree beta diversity in Amazonia

    ECOGRAPHY, Issue 4 2010
    Thaise Emilio
    Planning of conservation priorities has often taken mapped forest types as surrogates for biological complementarity. In the Brazilian Amazon, these exercises have given equal weight to each forest type as if they were all equally distinct. Here, we examine floristic similarity between forest types to assess the reliability of vegetation maps as a surrogate for canopy tree-community composition. We analyzed floristic differences at the genus level between twelve Amazonian forest types using 1184 one-hectare inventories of large trees with three complementary approaches. First, we compared a map of floristic composition, from a uni-dimensional NMDS ordination of the inventories, with a map of coarser-level forest types commonly recognized as distinct by classification systems across Amazonia. Using Mantel and means-difference tests, we next examined the distance-decay of floristic similarity for all paired samples and for the pairs drawn from within and between twelve more finely divided forest types. Finally, we examined the degree of floristic separation of each pair of the twelve forest types using non-parametric analysis of variance. Maps of floristic composition and coarse-level forest types were highly congruent. At the finer level of classification, similarity was only slightly higher when pairs were drawn from the same versus from different forest types. This was true for all geographic distances. Nonetheless, eighty percent of the 66 paired combinations of forest types were significantly different in the unreduced genus-space and nearly half showed little or no overlap in a two-dimensional ordination. Three types were most distinct from all others: white sand, seasonally dry, and bamboo-dominated forests. Here, we show that forest types exhibit variable degrees of separation. For this reason, treating all fine-level forest types as equally distinct results in poor representation of canopy tree beta diversity. We recommend explicitly considering the degree of floristic separation between all forest types , as presented here for Amazonian flora , as a way to improve the use of this biodiversity surrogate. [source]


    Conversion of hardwood forests to spruce and pine plantations strongly reduced soil methane sink in Germany

    GLOBAL CHANGE BIOLOGY, Issue 6 2003
    WERNER BORKEN
    Abstract Well-drained forest soils are thought to be a significant sink for atmospheric methane. Recent research suggests that land use change reduces the soil methane sink by diminishing populations of methane oxidizing bacteria. Here we report soil CH4 uptake from ,natural' mature beech forests and from mature pine and spruce plantations in two study areas of Germany with distinct climate and soils. The CH4 uptake rates of both beech forests at Solling and Unterlüß were about two,three times the CH4 uptake rates of the adjacent pine and spruce plantations, indicating a strong impact of forest type on the soil CH4 sink. The CH4 uptake rates of sieved mineral soils from our study sites confirmed the tree species effect and indicate that methanotrophs were mainly reduced in the 0,5 cm mineral soil depth. The reasons for the reduction are still unknown. We found no site effect between Solling and Unterlüß, however, CH4 uptake rates from Solling were significantly higher at the same effective CH4 diffusivity. This potential site effect was masked by higher soil water contents at Solling. Soil pH (H2O) explained 71% of the variation in CH4 uptake rates of sieved mineral soils from the 0,5 cm depth, while cation exchange capacity, soil organic carbon, soil nitrogen and total phosphorous content were not correlated with CH4 uptake rates. Comparing 1998,99, annual CH4 uptake rates increased by 69,111% in the beech and spruce stands and by 5,25% in the pine stands, due primarily to differences in growing season soil moisture. Cumulative CH4 uptake rates from November throughout April were rather constant in both years. The CH4 uptake rates of each stand were separately predicted using daily average soil matric potential and a previously developed empirical model. The model results revealed that soil matric potential explains 53,87% of the temporal variation in CH4 uptake. The differences between measured and predicted annual CH4 uptake rates were less than 10%, except for the spruce stand at Solling in 1998 (17%). Based on data from this study and from the literature, we calculated a total reduction in the soil CH4 sink of 31% for German forests due in part to conversion of deciduous to coniferous forests. [source]


    Leaf litter nitrogen concentration as related to climatic factors in Eurasian forests

    GLOBAL ECOLOGY, Issue 5 2006
    Chunjiang Liu
    ABSTRACT Aim, The aim of this study is to determine the patterns of nitrogen (N) concentrations in leaf litter of forest trees as functions of climatic factors, annual average temperature (Temp, °C) and annual precipitation (Precip, dm) and of forest type (coniferous vs. broadleaf, deciduous vs. evergreen, Pinus, etc.). Location, The review was conducted using data from studies across the Eurasian continent. Methods, Leaf litter N concentration was compiled from 204 sets of published data (81 sets from coniferous and 123 from broadleaf forests in Eurasia). We explored the relationships between leaf litter N concentration and Temp and Precip by means of regression analysis. Leaf litter data from N2 -fixing species were excluded from the analysis. Results, Over the Eurasian continent, leaf litter N concentration increased with increasing Temp and Precip within functional groups such as conifers, broadleaf, deciduous, evergreen and the genus Pinus. There were highly significant linear relationships between ln(N) and Temp and Precip (P < 0.001) for all available data combined, as well as for coniferous trees, broadleaf trees, deciduous trees, evergreen trees and Pinus separately. With both Temp and Precip as independent variables in multiple regression equations, the adjusted coefficient of determination () was evidently higher than in simple regressions with either Temp or Precip as independent variable. Standardized regression coefficients showed that Temp had a larger impact than Precip on litter N concentration for all groups except evergreens. The impact of temperature was particularly strong for Pinus. Conclusions, The relationship between leaf litter N concentration and temperature and precipitation can be well described with simple or multiple linear regression equations for forests over Eurasia. In the context of global warming, these regression equations are useful for a better understanding and modelling of the effects of geographical and climatic factors on leaf litter N at a regional and continental scale. [source]


    Comparison of structure and biodiversity in the Rajhenav virgin forest remnant and managed forest in the Dinaric region of Slovenia

    GLOBAL ECOLOGY, Issue 3 2000
    Andrej Boncina
    Abstract Comparisons are made between a virgin forest remnant (primeval forest) and a lightly managed (near-to-nature) forest with regard to horizontal forest structures, the structure of forest stands, and the diversity of plant and bird species. In the virgin forest remnant the proportion of canopy gaps is smaller, there are no stands in the developmental phase of a pole stand (10 < cm d.b.h. < 30 cm), and both the growing stock and the proportion of less vigorous trees are considerably greater. In addition, there is a higher percentage of dead trees, a smaller proportion of minor tree species and a considerably lower diversity of plants. The diversity of bird species is similar for each forest type, but rare bird species are confined to the virgin forest remnant. The biological differences between the two types of forest have led to changes in the physical site conditions. The results of the research are valuable in assessing the consequences of near-to-nature forest management. [source]


    Quantification of termite attack on lying dead wood by a line intersection method in the Kabili-Sepilok Forest Reserve, Sabah, Malaysia

    INSECT CONSERVATION AND DIVERSITY, Issue 2 2008
    LENE BERGE
    Abstract., 1A line intersection method was used to estimate abundance (technically linear abundance: m1 m,2), biovolume (m3 ha,1) and size class distribution (defined by diameter) of lying dead wood in tropical forest. Additional semi-quantitative protocols assessed decay state (4 classes), termite attack (5 classes) and live termite occupancy (3 classes). 2Three forest types (kerangas, alluvial and sandstone) were sampled in the Kabili-Sepilok Forest Reserve of Eastern Sabah, using plots of 30 × 30 m. Approximately 50 man-hours were required per site, at a replication of three plots per site and three well-separated sites per forest type. 3Mean biovolume of lying dead wood exceeded 8 × 103 m3 ha,1 in kerangas (= heath) forest, with lower values in other types. Large items (> 19 cm diameter) were less than 10% of total abundance, but represented the largest biovolume, exceeding (alluvial) or equalling (kerangas) the total biovolumes of smaller categories combined. Most items (not less than 75%) were present as small wood (< 10 cm diameter). Items in the highest decay class had the highest biovolume. 4Termite attack was greater in the kerangas, where nearly 90% of items showed evidence of consumption, compared with 58% in the alluvial and 40% in the sandstone forests. Over 40% of items in the kerangas contained live termites compared with 25% in the alluvial and 15% in the sandstone. Items in the highest attack class (= almost total internal destruction) represented about one-half of the total biovolume available in the alluvial and kerangas forest types, and about one-third in the sandstone. [source]


    Improving the design and management of forest strips in human-dominated tropical landscapes: a field test on Amazonian dung beetles

    JOURNAL OF APPLIED ECOLOGY, Issue 4 2010
    Jos Barlow
    Summary 1.,The future of tropical forest species depends in part on their ability to survive in human-modified landscapes. Forest strips present a priority area for biodiversity research because they are a common feature of many managed landscapes, are often afforded a high level of legal protection, and can provide a cost-effective and politically acceptable conservation strategy. 2.,Despite the potential conservation benefits that could be provided by forest strips, ecologists currently lack sufficient evidence to inform policy and guide their design and management. 3.,We used a quasi-experimental landscape in the Brazilian Amazon to test the importance of four management-relevant variables (forest type, isolation distance, forest structure, and large mammal activity) on the potential biodiversity conservation value of narrow forest strips for dung beetles. 4.,Information-theoretic model selection based on AICc revealed strong support for the influence of large mammal activity and forest type on dung beetle abundance; isolation distance on species richness; and forest structure on the relative abundance of matrix-tolerant species. Multi-dimensional scaling showed a strong influence of forest type and isolation on community composition and structure, with riparian and dry-land strips having complementary sets of species. 5.,Synthesis and applications. To enhance the conservation value and ecological integrity of forest strips in human-modified landscapes we recommend that strip design considers both isolation distance and whether or not the strips encompass perennial streams. In addition, we identify the maintenance of forest structure and the protection of large mammal populations as being crucially important for conserving forest dung beetle communities. [source]


    Distinguishing between the nests of sympatric chimpanzees and gorillas

    JOURNAL OF APPLIED ECOLOGY, Issue 2 2007
    CRICKETTE SANZ
    Summary 1Our current inability to estimate precisely the population sizes of chimpanzees and gorillas across much of the Congo Basin has been detrimental to the development of conservation strategies for the preservation of these endangered apes. Systematic counts of nests are currently the most commonly used method to estimate ape abundance, but distinguishing between the nests of sympatric chimpanzees and gorillas has proven to be an enduring obstacle to estimating species-specific abundance. In general, the builder of more than 75% of nests recorded during surveys is undetermined. We hypothesized that sleeping habits and nest building patterns would allow us to differentiate between the nests of these apes. 2We constructed a predictive model using stepwise discriminant function analysis to determine characteristics that accurately distinguished between chimpanzee and gorilla nests. We analysed 13 variables associated with 3425 ape nests from three independent surveys conducted in the Goualougo Triangle of the Nouabalé-Ndoki National Park, Republic of Congo. 3The model correctly classified more than 90% of nests in our validation subsample. Nest height, nest type, forest type and understorey closure were identified as important variables for distinguishing between chimpanzee and gorilla nests at this site. Attributing nests to either species increased the precision of resulting density estimates, which enhanced the statistical power to detect trends in population fluctuation. 4Although specific variables may differ between study sites, we have demonstrated that predictive models to distinguish between the nests of sympatric chimpanzee and gorillas provide a promising approach to improving the quality of ape survey data. 5Synthesis and applications. Our study introduces an innovative solution to the dilemma of discriminating between the nests of sympatric chimpanzees and gorillas, which increases the specificity and precision of resulting ape abundance estimates. There is an urgent need to improve methods to evaluate and monitor remaining ape populations across western and central Africa that are experiencing the imminent threats of emergent diseases, poaching and expanding human development. Increasing the quality of density estimates from field survey data will aid in the development of local conservation initiatives, national strategies and international policies on behalf of remaining ape populations. [source]


    Does soil determine the boundaries of monodominant rain forest with adjacent mixed rain forest and maquis on ultramafic soils in New Caledonia?

    JOURNAL OF BIOGEOGRAPHY, Issue 6 2006
    J. Read
    Abstract Aim, To determine the soil characteristics of Nothofagus -dominated rain forests in an ultramafic region (i.e. soils having high concentrations of metals including Mg, Fe and Ni), and whether soil characteristics may explain the location of monodominant rain forest in relation to adjacent mixed rain forest and maquis (shrub-dominated vegetation). Location, New Caledonia. Methods, Soil characteristics were compared among six Nothofagus -dominated rain forests from a range of altitudes and topographic positions. At four of these sites, comparisons were made with soils of adjacent mixed rain forest and maquis. Results, Soil characteristics varied among the monodominant Nothofagus forests, largely due to differences between ultramafic soils and soils influenced by non-ultramafic intrusions. The soils of all vegetation types had low concentrations of nutrients, particularly P, K and Ca (both total and extractable/exchangeable), and high total concentrations of Ni, Fe, Cr and Mn. There were significant differences between the rain forests and adjacent maquis in soil concentrations of several elements (N, P, Ca, Mg and Mn), more so in surface soils than at depth, but much of this pattern may be caused by effects of vegetation on the soil, rather than of soil on the vegetation. However, there were no significant differences in soil concentrations of any mineral elements between Nothofagus forest and adjacent mixed rain forest. Main conclusions, We found no evidence for soil mediation of boundaries of Nothofagus rain forest with mixed rain forest, and little evidence for the boundaries of either forest type with maquis. We suggest that the local abrupt boundaries of these monodominant Nothofagus forests are directly related to temporal factors, such as time since the last wildfire and frequency of wildfire, and that disturbance is therefore a major causal factor in the occurrence of these forests. [source]


    Disturbance indicators and population decline of logged species in Mt. Elgon Forest, Kenya

    AFRICAN JOURNAL OF ECOLOGY, Issue 3 2010
    Joseph Hitimana
    Abstract Mount (Mt) Elgon forest in western Kenya is important for biodiversity, environmental protection and socio-economic development. Characterizing forest conditions is essential for evaluation of sustainable management and conservation activities. This paper covers findings of a study which determined and analysed indicators useful in monitoring disturbance levels in the Mt Elgon Forest. A systematic survey was carried out and covered 305 plots of 0.02 ha and 250 smaller nested regeneration plots along 10 belt transects that were distributed in five blocks within the moist lower montane forest type. Collected and analysed data include types of disturbance, tree species composition, abundance and logged species. Correlation breakdown among disturbance types revealed that, paths were indicators of the number of tree harvesting sites (rs =1.00, P < 0.01) and of de-vegetated areas through grass harvesting (rs = 0.90, P = 0.04). Solanum mauritianum Scop. was an indicator of old-charcoal production sites. Logging targeted 13 tree species and harvested trees with diameter at breast height above 20 cm. The most exploited species were Olea capensis L. and Deinbolia kilimandscharica Taub. All exploited species had low regeneration but tree regeneration was not an effective indicator of logging. Résumé La forêt du Mont Elgon, dans l'ouest du Kenya, est importante pour sa biodiversité, pour la protection de l'environnement et pour le développement socioéconomique. Il est essentiel de bien définir les caractéristiques de ses conditions pour pouvoir évaluer les activités de gestion durable et de conservation. Cet article reprend les résultats d'une étude qui a déterminé et analysé des indicateurs intéressants pour pouvoir suivre le niveau de perturbation dans la forêt du Mont Elgon. Une étude systématique fut menée, qui a couvert 305 parcelles de 0,02 ha et 250 plus petites parcelles de régénération incluses le long de 10 transects de ceinture, distribuées en cinq blocs dans la forêt humide de basse montagne. Les données récoltées et analysées comprennent les types de perturbation, la composition des espèces d'arbres, leur abondance et celles qui sont exploitées. Une rupture de corrélation parmi les types de perturbation a révélé que les sentiers étaient des indicateurs du nombre de sites oùétaient récoltés les arbres (rs = 1.00; P < 0.01) et de zones sans végétation à cause de la récolte de l'herbe (rs = 0.90; P < 0.04). Solanum mauritianum Scop. était un indicateur d'anciens sites de production de charbon de bois. Les coupes d'arbres concernaient 13 espèces dont le diamètre à hauteur de poitrine dépassait 20 cm. Les espèces les plus exploitées étaient Olea capensis L. et Deinbolia kilimandscharica Taub. Toutes les espèces exploitées avaient une faible régénération, mais une régénération d'arbres n'était pas un indicateur fiable d'anciennes coupes d'arbres. [source]


    Moist lower montane rainforest classification: a case study from Bwindi Impenetrable National Park, Uganda

    AFRICAN JOURNAL OF ECOLOGY, Issue 3 2010
    Tomas Chaigneau
    Abstract Moist lower montane vegetation has rarely been classified beyond broad zonational belts over large altitudinal ranges due to highly diverse species composition and structure. This study shows it is possible to further classify such forest types within Bwindi-Impenetrable National Park (BINP), and that these assemblages can be explained by a combination of environmental conditions and past management. Botanical and environmental data were collected along some 4000 m of linear transects from the area surrounding Mubwindi Swamp, BINP. Ordination using Nonmetric Multidimensional Scaling (NMDS) and classification using Two-way Indicator Species Analysis (TWINSPAN) successfully identified four different species assemblages. These forest types were then named on the basis of the ecological characteristics of the species within the group, and the environmental conditions influencing the distribution and past disturbance of the forest. The techniques used were in agreement for three out of the four forest types identified. Analysis using an environmental overlay showed a significant association between forest type and altitude. The results of this study indicate that a regional classification of forest types within moist lower montane forest belt using only tree species is possible, and that the forest types identified can be explained by environmental conditions and past management. Résumé La végétation humide de basse montagne a rarement été classée au-delà de larges ceintures de zonage portant sur des étendues de grandes amplitudes altitudinales, en raison de compositions et de structures d'espèces extrêmement diverses. Cette étude montre qu'il est possible de classer plus précisément de tels types forestiers dans le Parc National de la Forêt Impénétrable de Bwindi (BINP), et que l'on peut expliquer ces assemblages par une combinaison de conditions environnementales et de gestion passée. Des données botaniques et environnementales ont été collectées le long de quelque 4,000 m de transects linéaires à partir de la zone entourant le Marais de Mubwindi, au BINP. L'ordination par la Gradation non métrique multidimensionnelle et la classification utilisant l'Analyse TWINSPAN (Two-way Indicator Species Analysis) ont réussi à identifier quatre assemblages d'espèces différents. Ces types forestiers furent alors nommés en se basant sur les caractéristiques écologiques des espèces au sein du groupe ainsi que sur les conditions environnementales qui influencent la distribution et des perturbations anciennes des forêts. Les techniques utilisées se sont montrées cohérentes pour trois des quatre types de forêt identifiés. L'analyse utilisant une superposition environnementale a révélé une association significative entre type forestier et altitude. Les résultats de cette étude indiquent qu'une classification régionale des types forestiers dans la ceinture forestière humide qui entoure la basse montagne est possible en n'utilisant que trois espèces d'arbres, et que les types forestiers identifiés peuvent s'expliquer par les conditions environnementales et par la gestion antérieure. [source]


    Long-term canopy dynamics in a large area of temperate old-growth beech (Fagus crenata) forest: analysis by aerial photographs and digital elevation models

    JOURNAL OF ECOLOGY, Issue 6 2004
    YUKO HENBO
    Summary 1Long-term canopy dynamics in a large area of temperate old-growth beech forest in the Daisen Forest Reserve, south-western Japan (11.56 ha studied over 43 years), were investigated using digital elevation models (DEMs) of the canopy surface, constructed from aerial photographs taken in the growing season (i.e. with foliage) in 1958, 1978, 1992 and 2001. A ground surface DEM at the same resolution (a 2.5 × 2.5 m grid) was constructed using aerial photographs taken when foliage was absent (winter 2002). Canopy height data were obtained by calculating differences in elevation between the canopy and the ground surface, and a canopy height profile was constructed. 2Topographic data for a 4-ha plot, located within the 11.56-ha area, were obtained via a ground survey and used to validate the ground surface DEM derived from aerial photographs. 3Canopy height class distributions changed significantly over the 43 years. The total number of gaps, defined as areas where canopy height was , 15 m, decreased but total gap area increased over time. Total gap area in 2001 was twice that of 1958. The density of gaps decreased as gap size increased. 4Gap formation rates increased from 0.47% year,1 (1958,78) to 1.30% year,1 (1992,2001), with a mean of 0.77% year,1, and substantially exceeded closure rates, which fluctuated from 0.28% year,1 (1958,78) to 0.54% year,1 (1978,92), with a mean of 0.39% year,1. Gaps generally expanded and became connected to each other. 5Temporal variation in gap formation and closure might be correlated with the frequency and severity of typhoon disturbances but, if the observed trends continue, this old-growth beech stand may become an open stand. The long-term dynamics of this forest type appear to be far from equilibrium. [source]


    Environment, disturbance history and rain forest composition across the islands of Tonga, Western Polynesia

    JOURNAL OF VEGETATION SCIENCE, Issue 2 2006
    Janet Franklin
    Abstract Questions: How do forest types differ in their distinctiveness among islands in relation to environmental and anthropogenic disturbance gradients? Are biogeographic factors also involved? Location: Tonga, ca. 170 oceanic islands totalling 700 km2 spread across 8° of latitude in Western Polynesia. Method Relative basal area was analysed for 134 species of woody plants in 187 plots. We used clustering, indirect gradient analysis, and indicator species analysis to identify continuous and discontinuous variation in species composition across geographical, environmental and disturbance gradients. Partial DCA related environmental to compositional gradients for each major forest type after accounting for locality. CCA and partial CCA partitioned observed compositional variation into components explained by environment/disturbance, locality and covariation between them. Results: Differences among forest types are related to environment and degree of anthropogenic disturbance. After accounting for inter-island differences, compositional variation (1) in coastal forest types is related to substrate, steepness and proximity to coast; (2) in early-successional, lowland rain forest to proximity to the coast, steepness and cultivation disturbance; (3) in late-successional, lowland forest types to elevation. For coastal/littoral forests, most of the compositional variation (71%) is explained by disturbance and environmental variables that do not covary with island while for both early and late-successional forests there is a higher degree of compositional variation reflecting covariation between disturbance/environment and island. Conclusions: There are regional similarities, across islands, among littoral/coastal forest types dominated by widespread seawater-dispersed species. The early-successional species that dominate secondary forests are distributed broadly across islands and environmental gradients, consistent with the gradient-in-time model of succession. Among-island differences in early-successional forest may reflect differences in land-use practices rather than environmental differences or biogeographical history. In late-successional forests, variation in composition among islands can be partly explained by differences among islands and hypothesized tight links between species and environment. Disentangling the effects of anthropogenic disturbance history versus biogeographic history on late-successional forest in this region awaits further study. [source]


    Estimating net primary production of boreal forests in Finland and Sweden from field data and remote sensing

    JOURNAL OF VEGETATION SCIENCE, Issue 2 2004
    Daolan Zheng
    We calculated annual mean stem volume increment (AMSVI) and total litter fall to produce forest net primary production (NPP) maps at 1-km2 and half-degree resolutions in Finland and Sweden. We used a multi-scale methodology to link field inventory data reported at plot and forestry district levels through a remotely sensed total plant biomass map derived from 1-km2 AVHRR image. Total litter fall was estimated as function of elevation and latitude. Leaf litter fall, a surrogate for fine root production, was estimated from total litter fall by forest type. The gridded NPP estimates agreed well with previously reported NPP values, based on point measurements. Regional NPP increases from northeast to southwest. It is positively related to annual mean temperature and annual mean total precipitation (strongly correlated with temperature) and is negatively related to elevation at broad scale. Total NPP (TNPP) values for representative cells selected based on three criteria were highly correlated with simulated values from a process-based model (CEVSA) at 0.5° × 0.5° resolution. At 1-km2 resolution, mean above-ground NPP in the region was 408 g/m2/yr ranging from 172 to 1091 (standard deviation (SD) = 134). Mean TNPP was 563 (252 to 1426, SD = 176). Ranges and SD were reduced while the mean values of the estimated NPP stayed almost constant as cell size increased from 1-km2 to 0.5° × 0.5°, as expected. Nordic boreal forests seem to have lower productivity among the world boreal forests. [source]


    Forest History as a Basis for Ecosystem Restoration,A Multidisciplinary Case Study in a South Swedish Temperate Landscape

    RESTORATION ECOLOGY, Issue 2 2007
    Matts Lindbladh
    Abstract Basic knowledge of the previous forest types or ecosystem present in an area ought to be an essential part of all landscape restoration. Here, we present a detailed study of forest and land use history over the past 2,000 years, from a large estate in southernmost Sweden, which is currently undergoing a restoration program. In particular, the aim was to identify areas with long continuity of important tree species and open woodland conditions. We employed a multidisciplinary approach using paleoecological analyses (regional and local pollen, plant macrofossil, tree ring) and historical sources (taxation documents, land surveys, forest inventories). The estate has been dominated by temperate broad-leaved trees over most of the studied period. When a forest type of Tilia, Corylus, and Quercus started to decline circa 1,000 years ago, it was largely replaced by Fagus. Even though extensive planting of Picea started in mid-nineteenth century, Fagus and Quercus have remained rather common on the estate up to present time. Both species show continuity on different parts of the estate from eighteenth century up to present time, but in some stands, for the entire 2,000 years. Our suggestions for restoration do not aim for previous "natural" conditions but to maintain the spatial vegetational pattern created by the historical land use. This study gives an example of the spatial and temporal variation of the vegetation that has historically occurred within one area and emphasizes that information from one methodological technique provides only limited information about an area's vegetation history. [source]


    Early fate of Myristica hypargyraea seeds dispersed by Ducula pacifica in Tonga, Western Polynesia

    AUSTRAL ECOLOGY, Issue 4 2005
    HAYLEY J. MEEHAN
    Abstract Although pigeons from the genus Ducula are considered among the best avian dispersers of large seeds in Asia and the Pacific, little has been documented on their role. The early fate of dispersed and undispersed seeds of the large-seeded tree Myristica hypargyraea A. Gray was studied in order to understand the advantage of seed dispersal by the Pacific Pigeon, Ducula pacifica Gmelin in Tonga. Frequency of visits by frugivores to fruiting trees and dispersal distance of seeds were measured. Pre-dispersal vertebrate seed predation was assessed, then post-dispersal predation was measured over 160 days. Overall, pre-dispersal seed predation by parrots was low but variable among trees sampled. Most seeds (54.7%) in the study area were estimated to be dispersed by D. pacifica; 79.7% of those ingested were expelled directly beneath conspecific fruiting crowns, 20% were dispersed locally and <,0.3% were dispersed more than 300 m into a different forest type. Flying foxes (Pteropus tonganus Quoy and Gaimard) dispersed very few seeds (0.7%) and all were dropped below fruiting crowns. Between 4% and 39% of dispersed and undispersed seeds were still viable, or had established seedlings after 160 days. Most seeds had been removed or killed by rats, and seed survival was highest for locally dispersed seeds (approx. 20 m from source trees and within the M. hypargyraea forest). Although D. pacifica was the only frugivore observed to disperse seeds into this higher zone of survival, overall they did not confer a great advantage to seed survival since significant numbers of seeds/seedlings also persisted under fruiting crowns (27% under crowns compared with 39% locally dispersed). Nevertheless, D. pacifica was the only vector by which seeds were regularly moved within the M. hypargyraea forest and over longer distances, and hence, D. pacifica still plays a significant role in the regeneration of M. hypargyraea. [source]


    Sensitivity of tropical forests to climate change in the humid tropics of north Queensland

    AUSTRAL ECOLOGY, Issue 6 2001
    David W. Hilbert
    Abstract An analysis using an artificial neural network model suggests that the tropical forests of north Queensland are highly sensitive to climate change within the range that is likely to occur in the next 50,100 years. The distribution and extent of environments suitable for 15 structural forest types were estimated, using the model, in 10 climate scenarios that include warming up to 1°C and altered precipitation from ,10% to +20%. Large changes in the distribution of forest environments are predicted with even minor climate change. Increased precipitation favours some rainforest types, whereas decreased rainfall increases the area suitable for forests dominated by sclerophyllous genera such as Eucalyptus and Allocasuarina. Rainforest environments respond differentially to increased temperature. The area of lowland mesophyll vine forest environments increases with warming, whereas upland complex notophyll vine forest environments respond either positively or negatively to temperature, depending on precipitation. Highland rainforest environments (simple notophyll and simple microphyll vine fern forests and thickets), the habitat for many of the region's endemic vertebrates, decrease by 50% with only a 1°C warming. Estimates of the stress to present forests resulting from spatial shifts of forest environments (assuming no change in the present forest distributions) indicate that several forest types would be highly stressed by a 1°C warming and most are sensitive to any change in rainfall. Most forests will experience climates in the near future that are more appropriate to some other structural forest type. Thus, the propensity for ecological change in the region is high and, in the long term, significant shifts in the extent and spatial distribution of forests are likely. A detailed spatial analysis of the sensitivity to climate change indicates that the strongest effects of climate change will be experienced at boundaries between forest classes and in ecotonal communities between rainforest and open woodland. [source]


    Influence of Forest Type and Tree Species on Canopy-Dwelling Beetles in Budongo Forest, Uganda,

    BIOTROPICA, Issue 3 2000
    Thomas Wagner
    ABSTRACT Beetles were collected on 64 trees of four species (Cynometra alexandri C. H. Wright, Rinorea beniemis (Welwitsch ex Olivier) Kuntze, Teclea nobilis Delile, and Trichilia rubescens Olivier) in Budongo Forest, Uganda, using an insecticidal fogging technique. Selected tree species were abundant, taxonomically not closely related, and different in the shape of leaves, growth form, and size, with heights between 7 and 35 m. Trees were fogged in an old primary forest stand, in an area of secondary forest where selective logging was performed, and in a swamp forest. Eight conspecific trees per forest type were fogged. A total of 29,736 beetles were collected from all trees that could be assigned to 1433 (morpho)-species; 41.6 percent were singletons and 89.6 percent of species were found with less than ten individuals. Abundant beetle taxa included Latridiidae (N= 4093), Chrysomelidae (3952), Staphylinidae (2931), Apioninae (2621), and Curculionidae (2457). Most species-rich groups were Staphylinidae (N= 196 spp.), Curculionidae (189), and Chrysomelidae (148). Abundance increased in the order: primary < secondary < swamp forest. Due to the relatively high dominance of some species in the secondary forest, species richness increased in the order: secondary < primary < swamp forest. Beta diversity measures and factor analysis showed distinct differences among forest types but higher similarity of beetle communities on different tree species within one forest type. The taxonomic distribution of beetles in the secondary forest was more heterogeneous than in the primary forest. Analyses of the data revealed low host specificity even for phytophagous beetles, underlining the importance of habitat structure and chance effects on the spatial distribution of beetles in the canopy of Budongo Forest. [source]


    An Ecological and Economic Assessment of the Nontimber Forest Product Gaharu Wood in Gunung Palung National Park, West Kalimantan, Indonesia

    CONSERVATION BIOLOGY, Issue 6 2001
    Gary D. Paoli
    We studied the demographic effect and economic returns of harvesting aromatic gaharu wood from fungus-infected trees of Aquilaria malaccensis Lam. at Gunung Palung National Park, Indonesia, to evaluate the management potential of gaharu wood. Aquilaria malaccensis trees openface> 20 cm in diameter occurred at low preharvest densities (0.16,0.32 ha) but were distributed across five of six forest types surveyed. During a recent harvest, 75% of trees were felled, with harvest intensities ranging from 50% to 100% among forest types. Overall, 50% of trees contained gaharu wood, but trees at higher elevations contained gaharu wood more frequently ( 73%) than trees at lower elevation (27%). The mean density of regeneration ( juveniles> 15 cm in height) near adult trees (3,7 m away) was 0.2/m2, 200 times greater than at random in the forest (10/ha), but long-term data on growth and survivorship are needed to determine whether regeneration is sufficient for population recovery. Gaharu wood extraction from Gunung Palung was very profitable for collectors, generating an estimated gross financial return per day of US $8.80, triple the mean village wage. Yet, the estimated sustainable harvest of gaharu wood at natural tree densities generates a mean net present value of only $10.83/ha, much lower than that of commercial timber harvesting, the dominant forest use in Kalimantan. Returns per unit area could be improved substantially, however, by implementing known silvicultural methods to increase tree densities, increase the proportion of trees that produce gaharu wood, and shorten the time interval between successive harvests. The economic potential of gaharu wood is unusual among nontimber forest products and justifies experimental trials to develop small-scale cultivation methods. Resumen: Datos ecológicos y económicos son esenciales para la identificación de productos forestales no maderables tropicales con potencial para la extracción sostenible y rentable en un sistema bajo manejo. Estudiamos el efecto demográfico y los beneficios económicos de la cosecha de la madera aromática gaharu de árboles de Aquilaria malaccenis Lam infectados por hongos en el Parque Nacional Gunung Palung Indonesia para evaluar el potencial de manejo de la madera. Arboles de Aquilaria malaccenis> 20 cm de diámetro ocurrieron en bajas densidades precosecha (0.16,0.32 ha,1) pero se distribuyeron en cinco de los seis tipos de bosque muestreados. Durante una cosecha reciente, 75% de los árboles fueron cortados, con intensidades de cosecha entre 50 y 100% en los tipos de bosque. En conjunto, 50% de los árboles contenían madera gaharu, pero árboles de elevaciones mayores contenían madera gaharu más frecuentemente ( 73%) que árboles de elevaciones menores (27%). La densidad promedio de regeneración ( juveniles> 15 cm de altura) cerca de árboles adultos (de 3 a 7 m de distancia) fue de 0.2 m,2, 200 veces mayor que en el bosque (10 ha,1), pero se requieren datos a largo plazo sobre el crecimiento y la supervivencia para determinar si la regeneración es suficiente para la recuperación de la población. La extracción de madera gaharu de Gunung Palung fue muy redituable, generando un rendimiento financiero bruto estimado en US $8.80 diarios, el triple del salario promedio en la zona. Sin embargo, la cosecha sostenible estimada de madera gaharu en densidades naturales de árboles genera un valor presente neto de sólo $10.83 ha,1, mucho menor que el de la cosecha comercial de madera, uso dominante del bosque en Kalimantan. Sin embargo, los rendimientos por unidad de área podrían mejorar sustancialmente mediante la instrumentación de métodos silviculturales para incrementar la densidad de árboles, incrementar la proporción de árboles que producen madera gaharu y reducir el intervalo de tiempo entre cosechas sucesivas. El potencial económico de la madera gaharu es poco usual entre los productos forestales no maderables y justifica la experimentación para desarrollar métodos de cultivo en pequeña escala. [source]


    Assessing the relationship between forest types and canopy tree beta diversity in Amazonia

    ECOGRAPHY, Issue 4 2010
    Thaise Emilio
    Planning of conservation priorities has often taken mapped forest types as surrogates for biological complementarity. In the Brazilian Amazon, these exercises have given equal weight to each forest type as if they were all equally distinct. Here, we examine floristic similarity between forest types to assess the reliability of vegetation maps as a surrogate for canopy tree-community composition. We analyzed floristic differences at the genus level between twelve Amazonian forest types using 1184 one-hectare inventories of large trees with three complementary approaches. First, we compared a map of floristic composition, from a uni-dimensional NMDS ordination of the inventories, with a map of coarser-level forest types commonly recognized as distinct by classification systems across Amazonia. Using Mantel and means-difference tests, we next examined the distance-decay of floristic similarity for all paired samples and for the pairs drawn from within and between twelve more finely divided forest types. Finally, we examined the degree of floristic separation of each pair of the twelve forest types using non-parametric analysis of variance. Maps of floristic composition and coarse-level forest types were highly congruent. At the finer level of classification, similarity was only slightly higher when pairs were drawn from the same versus from different forest types. This was true for all geographic distances. Nonetheless, eighty percent of the 66 paired combinations of forest types were significantly different in the unreduced genus-space and nearly half showed little or no overlap in a two-dimensional ordination. Three types were most distinct from all others: white sand, seasonally dry, and bamboo-dominated forests. Here, we show that forest types exhibit variable degrees of separation. For this reason, treating all fine-level forest types as equally distinct results in poor representation of canopy tree beta diversity. We recommend explicitly considering the degree of floristic separation between all forest types , as presented here for Amazonian flora , as a way to improve the use of this biodiversity surrogate. [source]


    Long-term reproductive behaviour of woody plants across seven Bornean forest types in the Gunung Palung National Park (Indonesia): suprannual synchrony, temporal productivity and fruiting diversity

    ECOLOGY LETTERS, Issue 10 2007
    Charles H. Cannon
    Abstract For 68 months, we observed the reproductive behaviour of 7288 woody plants (172 figs, 1457 climbers and 5659 trees) spanning major soil and elevational gradients. Two 2,3 month community-wide supra-annual fruiting events were synchronized across five forest types, coinciding with ENSO events. At least 27 genera in 24 families restricted their reproduction to these events, which involved a substantial proportion of tree diversity (> 80% of phylogenetic diversity). During these events, mean reproductive levels (8.5%) represented an almost four-fold increase compared with other months. These patterns indicate a strong behavioural advantage to this unusual reproductive behaviour. Montane forest experienced a single, separate fruiting peak while the peat swamp forest did not participate. Excluding these events, no temporal reproductive pattern was detectible, at either the landscape or forest type. These phenological patterns have major implications for the conservation of frugivore communities, with montane and swamp forests acting as ,keystone' forests. [source]


    A new fossil species of Polypodium (Polypodiaceae) from the Oligocene of northern Bohemia (Czech Republic)

    FEDDES REPERTORIUM, Issue 3-4 2001
    Z. Kvacek
    A new fossil representative of Polypodium L. emend. CHING (Polypodiaceae s.str.) was recovered in the Early Oligocene diatomite shales of the Ceske stredohori Mountains, North Bohemia (localities Bechlejovice, Holy Kluk hill). Polypodium radonii sp. nova is characterised on the basis of fragmentary fronds, which have simple pinnatifid laminas, entire pinnae, free, anadromously branched venation, solitary broadly elliptic superficial sori and monolete spores in situ of the Polypodiisporites bock-witzensis type. This terrestrial (? to epiphytic or epilithic) fern was associated with vegetation of subtropical Mixed Mesophytic (Holy Kluk) and warm temperate Deciduous Broad-leaved (Bechlejovice) forest types. Actual taxonomy of extant Polypodiaceae s.str. as well as the Tertiary records of this fern group within the Holarctis are reviewed. [source]


    Sources of plant-derived carbon and stability of organic matter in soil: implications for global change

    GLOBAL CHANGE BIOLOGY, Issue 8 2009
    SUSAN E. CROW
    Abstract Alterations in forest productivity and changes in the relative proportion of above- and belowground biomass may have nonlinear effects on soil organic matter (SOM) storage. To study the influence of plant litter inputs on SOM accumulation, the Detritus Input Removal and Transfer (DIRT) Experiment continuously alters above- and belowground plant inputs to soil by a combination of trenching, screening, and litter addition. Here, we used biogeochemical indicators [i.e., cupric oxide extractable lignin-derived phenols and suberin/cutin-derived substituted fatty acids (SFA)] to identify the dominant sources of plant biopolymers in SOM and various measures [i.e., soil density fractionation, laboratory incubation, and radiocarbon-based mean residence time (MRT)] to assess the stability of SOM in two contrasting forests within the DIRT Experiment: an aggrading deciduous forest and an old-growth coniferous forest. In the deciduous forest, removal of both above- and belowground inputs increased the total amount of SFA over threefold compared with the control, and shifted the SFA signature towards a root-dominated source. Concurrently, light fraction MRT increased by 101 years and C mineralization during incubation decreased compared with the control. Together, these data suggest that root-derived aliphatic compounds are a source of SOM with greater relative stability than leaf inputs at this site. In the coniferous forest, roots were an important source of soil lignin-derived phenols but needle-derived, rather than root-derived, aliphatic compounds were preferentially preserved in soil. Fresh wood additions elevated the amount of soil C recovered as light fraction material but also elevated mineralization during incubation compared with other DIRT treatments, suggesting that not all of the added soil C is directly stabilized. Aboveground needle litter additions, which are more N-rich than wood debris, resulted in accelerated mineralization of previously stored soil carbon. In summary, our work demonstrates that the dominant plant sources of SOM differed substantially between forest types. Furthermore, inputs to and losses from soil C pools likely will not be altered uniformly by changes in litter input rates. [source]


    Trends and methodological impacts in soil CO2 efflux partitioning: A metaanalytical review

    GLOBAL CHANGE BIOLOGY, Issue 6 2006
    JENS-ARNE SUBKE
    Abstract Partitioning soil carbon dioxide (CO2) efflux (RS) into autotrophic (RA; including plant roots and closely associated organisms) and heterotrophic (RH) components has received considerable attention, as differential responses of these components to environmental change have profound implications for the soil and ecosystem C balance. The increasing number of partitioning studies allows a more detailed analysis of experimental constraints than was previously possible. We present results of an exhaustive literature search of partitioning studies and analyse global trends in flux partitioning between biomes and ecosystem types by means of a metaanalysis. Across all data, an overall decline in the RH/RS ratio for increasing annual RS fluxes emerged. For forest ecosystems, boreal coniferous sites showed significantly higher (P<0.05) RH/RS ratios than temperate sites, while both temperate or tropical deciduous forests did not differ in ratios from any of the other forest types. While chronosequence studies report consistent declines in the RH/RS ratio with age, no difference could be detected for different age groups in the global data set. Different methodologies showed generally good agreement if the range of RS under which they had been measured was considered, with the exception of studies estimating RH by means of root mass regressions against RS, which resulted in consistently lower RH/RS estimates out of all methods included. Additionally, the time step over which fluxes were partitioned did not affect RH/RS ratios consistently. To put results into context, we review the most common techniques and point out the likely sources of errors associated with them. In order to improve soil CO2 efflux partitioning in future experiments, we include methodological recommendations, and also highlight the potential interactions between soil components that may be overlooked as a consequence of the partitioning process itself. [source]


    Evaluation of six process-based forest growth models using eddy-covariance measurements of CO2 and H2O fluxes at six forest sites in Europe

    GLOBAL CHANGE BIOLOGY, Issue 3 2002
    K. Kramer
    Abstract Reliable models are required to assess the impacts of climate change on forest ecosystems. Precise and independent data are essential to assess this accuracy. The flux measurements collected by the EUROFLUX project over a wide range of forest types and climatic regions in Europe allow a critical testing of the process-based models which were developed in the LTEEF project. The ECOCRAFT project complements this with a wealth of independent plant physiological measurements. Thus, it was aimed in this study to test six process-based forest growth models against the flux measurements of six European forest types, taking advantage of a large database with plant physiological parameters. The reliability of both the flux data and parameter values itself was not under discussion in this study. The data provided by the researchers of the EUROFLUX sites, possibly with local corrections, were used with a minor gap-filling procedure to avoid the loss of many days with observations. The model performance is discussed based on their accuracy, generality and realism. Accuracy was evaluated based on the goodness-of-fit with observed values of daily net ecosystem exchange, gross primary production and ecosystem respiration (gC m,2 d,1), and transpiration (kg H2O m,2 d,1). Moreover, accuracy was also evaluated based on systematic and unsystematic errors. Generality was characterized by the applicability of the models to different European forest ecosystems. Reality was evaluated by comparing the modelled and observed responses of gross primary production, ecosystem respiration to radiation and temperature. The results indicated that: Accuracy. All models showed similar high correlation with the measured carbon flux data, and also low systematic and unsystematic prediction errors at one or more sites of flux measurements. The results were similar in the case of several models when the water fluxes were considered. Most models fulfilled the criteria of sufficient accuracy for the ability to predict the carbon and water exchange between forests and the atmosphere. Generality. Three models of six could be applied for both deciduous and coniferous forests. Furthermore, four models were applied both for boreal and temperate conditions. However, no severe water-limited conditions were encountered, and no year-to-year variability could be tested. Realism. Most models fulfil the criterion of realism that the relationships between the modelled phenomena (carbon and water exchange) and environment are described causally. Again several of the models were able to reproduce the responses of measurable variables such as gross primary production (GPP), ecosystem respiration and transpiration to environmental driving factors such as radiation and temperature. Stomatal conductance appears to be the most critical process causing differences in predicted fluxes of carbon and water between those models that accurately describe the annual totals of GPP, ecosystem respiration and transpiration. As a conclusion, several process-based models are available that produce accurate estimates of carbon and water fluxes at several forest sites of Europe. This considerable accuracy fulfils one requirement of models to be able to predict the impacts of climate change on the carbon balance of European forests. However, the generality of the models should be further evaluated by expanding the range of testing over both time and space. In addition, differences in behaviour between models at the process level indicate requirement of further model testing, with special emphasis on modelling stomatal conductance realistically. [source]


    Assessing forest growth across southwestern Oregon under a range of current and future global change scenarios using a process model, 3-PG

    GLOBAL CHANGE BIOLOGY, Issue 1 2001
    N. C. Coops
    Summary With improvements in mapping regional distributions of vegetation using satellite-derived information, there is an increasing interest in the assessment of current limitations on forest growth and in making projections of how productivity may be altered in response to changing climatic conditions and management policies. We utilised a simplified physiologically based process model (3-PG) across a 54 000 km2 mountainous region of southwestern Oregon, USA, to evaluate the degree to which maximum periodic mean annual increment (PAI) of forests could be predicted at a set of 448 forest inventory plots. The survey data were pooled into six broad forest types (coastal rain forest, interior coast range forest, mixed conifer, dry-site Douglas-fir, subalpine forest, and pine forest) and compared to the 3-PG predictions at a spatial resolution of 1 km2. We found good agreement (r2 = 0.84) between mean PAI values of forest productivity for the six forest types with those obtained from field surveys. With confidence at this broader level of integration, we then ran model simulations to evaluate the constraints imposed by (i) soil fertility under current climatic conditions, (ii) the effect of doubling monthly precipitation across the region, and (iii) a widely used climatic change scenario that involves modifications in monthly mean temperatures and precipitation, as well as a doubling in atmospheric CO2 concentrations. These analyses showed that optimum soil fertility would more than double growth, with the greatest response in the subalpine type and the least increase in the coastal rain forests. Doubling the precipitation increased productivity in the pine type (> 50%) with reduced responses elsewhere. The climate change scenario with doubled atmospheric CO2 increased growth by 50% on average across all forest types, primarily as a result of a projected 33% increase in photosynthetic capacity. This modelling exercise indicates that, at a regional scale, a general relationship exists between simulated maximum leaf area index and maximum aboveground growth, supporting the contention that satellite-derived estimates of leaf area index may be good measures of the potential productivity of temperate evergreen forests. [source]


    The solute budget of a forest catchment and solute fluxes within a Pinus radiata and a secondary native forest site, southern Chile

    HYDROLOGICAL PROCESSES, Issue 13 2002
    Geertrui Y. P. Uyttendaele
    Abstract Solute concentrations and fluxes in rainfall, throughfall and stemflow in two forest types, and stream flow in a 90 ha catchment in southern Chile (39°44,S, 73°10,W) were measured. Bulk precipitation pH was 6·1 and conductivity was low. Cation concentrations in rainfall were low (0·58 mg Ca2+ l,1, 0·13 mg K+ l,1, 0·11 mg Mg2+ l,1 and <0·08 mg NH4,N l,1), except for sodium (1·10 mg l,1). Unexpected high levels of nitrate deposition in rainfall (mean concentration 0·38 mg NO3,N l,1, total flux 6·3 kg NO3,N ha,1) were measured. Concentrations of soluble phosphorous in bulk precipitation and stream flow were below detection limits (<0·09 mg l,1) for all events. Stream-flow pH was 6·3 and conductivity was 28·3 ,s. Stream-water chemistry was also dominated by sodium (2·70 mg l,1) followed by Ca, Mg and K (1·31, 0·70 and 0·36 mg l,1). The solute budget indicated a net loss of 3·8 kg Na+ ha,1 year,1, 5·4 kg Mg2+ ha,1 year,1, 1·5 kg Ca2+ ha,1 year,1 and 0·9 kg K+ ha,1 year,1, while 4·9 kg NO3,N ha,1 year,1 was retained by the ecosystem. Stream water is not suitable for domestic use owing to high manganese and, especially, iron concentrations. Throughfall and stemflow chemistry at a pine stand (Pinus radiata D. Don) and a native forest site (Siempreverde type), both located within the catchment, were compared. Nitrate fluxes within both forest sites were similar (1·3 kg NO3,N ha,1 year,1 as throughfall). Cation fluxes in net rainfall (throughfall plus stemflow) at the pine stand generally were higher (34·8 kg Na+ ha,1 year,1, 21·5 kg K+ ha,1 year,1, 5·1 kg Mg2+ ha,1 year,1) compared with the secondary native forest site (24·7 kg Na+ ha,1 year,1, 18·9 kg K+ ha,1 year,1 and 4·4 kg Mg2+ ha,1 year,1). However, calcium deposition beneath the native forest stand was higher (15·9 kg Ca2+ ha,1 year,1) compared with the pine stand (12·6 kg Ca2+ ha,1 year,1). Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Quantification of termite attack on lying dead wood by a line intersection method in the Kabili-Sepilok Forest Reserve, Sabah, Malaysia

    INSECT CONSERVATION AND DIVERSITY, Issue 2 2008
    LENE BERGE
    Abstract., 1A line intersection method was used to estimate abundance (technically linear abundance: m1 m,2), biovolume (m3 ha,1) and size class distribution (defined by diameter) of lying dead wood in tropical forest. Additional semi-quantitative protocols assessed decay state (4 classes), termite attack (5 classes) and live termite occupancy (3 classes). 2Three forest types (kerangas, alluvial and sandstone) were sampled in the Kabili-Sepilok Forest Reserve of Eastern Sabah, using plots of 30 × 30 m. Approximately 50 man-hours were required per site, at a replication of three plots per site and three well-separated sites per forest type. 3Mean biovolume of lying dead wood exceeded 8 × 103 m3 ha,1 in kerangas (= heath) forest, with lower values in other types. Large items (> 19 cm diameter) were less than 10% of total abundance, but represented the largest biovolume, exceeding (alluvial) or equalling (kerangas) the total biovolumes of smaller categories combined. Most items (not less than 75%) were present as small wood (< 10 cm diameter). Items in the highest decay class had the highest biovolume. 4Termite attack was greater in the kerangas, where nearly 90% of items showed evidence of consumption, compared with 58% in the alluvial and 40% in the sandstone forests. Over 40% of items in the kerangas contained live termites compared with 25% in the alluvial and 15% in the sandstone. Items in the highest attack class (= almost total internal destruction) represented about one-half of the total biovolume available in the alluvial and kerangas forest types, and about one-third in the sandstone. [source]


    Movement trajectories and habitat partitioning of small mammals in logged and unlogged rain forests on Borneo

    JOURNAL OF ANIMAL ECOLOGY, Issue 5 2006
    KONSTANS WELLS
    Summary 1Non-volant animals in tropical rain forests differ in their ability to exploit the habitat above the forest floor and also in their response to habitat variability. It is predicted that specific movement trajectories are determined both by intrinsic factors such as ecological specialization, morphology and body size and by structural features of the surrounding habitat such as undergrowth and availability of supportive structures. 2We applied spool-and-line tracking in order to describe movement trajectories and habitat segregation of eight species of small mammals from an assemblage of Muridae, Tupaiidae and Sciuridae in the rain forest of Borneo where we followed a total of 13 525 m path. We also analysed specific changes in the movement patterns of the small mammals in relation to habitat stratification between logged and unlogged forests. Variables related to climbing activity of the tracked species as well as the supportive structures of the vegetation and undergrowth density were measured along their tracks. 3Movement patterns of the small mammals differed significantly between species. Most similarities were found in congeneric species that converged strongly in body size and morphology. All species were affected in their movement patterns by the altered forest structure in logged forests with most differences found in Leopoldamys sabanus. However, the large proportions of short step lengths found in all species for both forest types and similar path tortuosity suggest that the main movement strategies of the small mammals were not influenced by logging but comprised generally a response to the heterogeneous habitat as opposed to random movement strategies predicted for homogeneous environments. 4Overall shifts in microhabitat use showed no coherent trend among species. Multivariate (principal component) analysis revealed contrasting trends for convergent species, in particular for Maxomys rajah and M. surifer as well as for Tupaia longipes and T. tana, suggesting that each species was uniquely affected in its movement trajectories by a multiple set of environmental and intrinsic features. [source]