Different Types Of Forest Research Articles

Potworm communities (Enchytraeidae, Oligochaeta) in different types of forest in Puszcza Kampinoska

24 potworm specles have been found in the forest habitats studied in Puszcza Kampinoska. Species diversitv of Enchytraeidae decreases with deteriorating trophic and moisture conditions. Potworm communities in alder swamps and mixed forests have a characteristic species cornposition and structure. Linden-oak-hornbeam forests with a variety of habitats present accomrnodate a number ofdistinct potworm communities.

Red-listed lichens in Sweden: habitats, threats, protection, and indicator value in boreal coniferous forests

The three major threats to lichens in Sweden; forestry, air pollution, and structural changes in the agricultural landscape, are outlined. Forestry is the most serious. The majority of the red-listed lichens in forests are found in productive forests with a continuity in tree growth, but nearly 70% of the protected area in Sweden consists of alpine landscapes. Examples of important habitats with red-listed lichens are described, e.g. Alnus glutinosa marshes, alvar-vegetation, broad-leaved deciduous forests and different Picea abies forests. The use of selected indicator species of lichens and macrofungi (mainly red-listed species) in boreal coniferous forests provides information on continuity in tree growth of an area, and on earlier influences of forestry. Examples of indicator species for different types of forest are presented and discussed. In spite of the Swedish ‘right of common access’o, collecting of lichens is forbidden without permission from the land-owner. Collecting in protected areas is allowed only with a permit obtained from the authorities.

Characteristics and Adaptive Significance of Latrines of Swamp Rabbits (Sylvilagus aquaticus)

Three different types of forests (mature, mixed upland, and cut-over) in central Arkansas were surveyed in June and October 1991 and February and May 1992 for latrines of swamp rabbits ( Sylvilagus aquaticus ). Swamp rabbits deposited >91% of their fecal pellets on logs. A greater density of pellets were found in February 1992 compared to other months. Length, height, diameter, decay class, and percent cover of moss on logs used as latrines by swamp rabbits were recorded. Logistic regression was used to predict the likelihood that a log would be used as a latrine. Increasing decay class, percentage cover of moss, and diameter of logs were correlated with latrines of swamp rabbits. Height of logs did not distinguish between used and unused logs, but length and season were significant predictors of use of logs as latrines in forests of mature bottomland hardwood and cut-over bottomland. Spatial clumping of latrines and peak use during breeding were consistent with the hypothesis that latrines on logs serve as territorial markers. An alternative hypothesis that swamp rabbits elevated themselves on logs to increase their field of view and coincidentally deposited pellets on logs was tested experimentally with three obstruction treatments; visual + physical, only physical, and a control. Treatments were placed on 1-m sections of 54 logs that had been used as latrines in at least 2 of the 4 monthly surveys. Surveys conducted for 4 months after the installation of obstructions showed a significant interaction between use of a log as a latrine, treatment type, and month of survey.

APPLICATION OF REMOTE SENSING TO STUDY THE ENVIRONMENT AND ECOSYSTEM: A CASE STUDY FOR FOREST COVER MAPPING

Remote sensing technique can be better utilised for identifying different types of forest cover in a tropical forest eco-system. Four major forest types and one type of grassland vegetation were identified on satellite imageries. By using aerial photographs, 11 forest types and 4 types of grasslands were identified from the same study area. By integrating the interpreted information of aerial photographs and satellite imageries, it was possible to identify different types of forest and their areal extent by converting the information into a two dimensional forest cover map

Boreal forest futures: Modelling the controls on tree species range limits and transient responses to climate change

Range limits and broad-scale geographic variations in the productivity of boreal and northern deciduous tree species in Europe are simulated with a bioclimatic model (STASH). STASH is based on a small number of distinct mechanisms by which climate is thought to affect the survival, regeneration and growth of trees. Survival is limited by summer warmth requirements and winter cold tolerance; regeneration, additionally by winter chilling requirements; and growth rate by net assimilation, which in turn is related to photosynthetically active radiation, growing-season length, temperature (relative to species-specific optima) and soil moisture supply (relative to evaporative demand). These mechanisms are quantified either as thresholds (for survival and regeneration) or multipliers (for growth), based on bioclimatic variables computed from monthly climate normals interpolated three-dimensionally to a 10-minute grid. Growing-season and growing degree day calculations take into account the effects of chilling. The drought calculations also take into account the effects of soil-moisture storage by means of a physically based evapotranspiration calculation coupled to a one-layer soil hydrology model. STASH is used to examine changes in potential range limits under a 2×CO2 climate-change scenario. Associated transient responses at selected sites in the boreal and boreo-nemoral zones of Sweden are also simulated, using the forest gap model FORSKA2. The species-specific survival and regeneration constraints and growth responses of STASH modify the growth, establishment and mortality of trees in FORSKA2. The results obtained in this way differ sharply from the results of conventional forest gap models, where growth rates are assumed to decline to zero at minimum and maximum growing degree day limits. For example, towards the southern limit of Picea abies (Norway spruce), STASH correctly shows no decline in productivity, but rather an abrupt cut-off corresponding to a chilling requirement during regeneration that is not met further south or west. In transient warming scenarios, this mechanism has the effect that natural regeneration can be blocked due to the warm winters even as yield is increasing due to the longer and warmer summers. STASH predicts drastic changes in species distributions in response to the large climate changes (especially winter warming) expected for northern Europe. Some of the common boreal species (e.g., Picea abies; Pinus sylvestris; Alnus incana) are unlikely to survive in much of their present range, withdrawing to the far north. Other species already widespread may be able to occupy some of the few sites that are today unavailable to them (e.g., Betula spp.; Corylus avellana). Other temperate deciduous species such as Fagus sylvatica could have dramatic range expansions, potentially occupying large tracts of the present boreal zone. FORSKA2 transient simulations illustrate some of the possible routes towards different types of forest in a changed climate. Some sites in the north show little change in species composition, but sites towards the southern boundary of the boreal zone could develop a new suite of dominants. The degree of sensitivity of a particular site depends both on the climate change prediction and on the transient dynamics of the forest community. Many types of transient behaviour are shown to be possible. Coupled with uncertainties about the future role of dispersal and changes in disturbance rate, the complexity and variety of these transient responses imply a highly uncertain future for the north European boreal forests.

Forest mapping from multi‐source satellite data using neural network classifiers—an experiment in Portugal

Abstract The monitoring of forest ecosystems and their biodiversity is a major challenge for satellite remote sensing. The opportunity now exists for operationally using multi‐sensor high resolution satellite data from optical, infrared and microwave parts of the electromagnetic spectrum. An experiment is reported on the integrated use of Landsat Thematic Mapper (TM) imagery combined with ERS‐1 Synthetic Aperture Radar (SAR) imagery for mapping eight identifiable types of forest ecosystem in a test area of approximately 100 x 100 km in western central Portugal. The TM and SAR images were geometrically co‐registered and resampled to a spatial resolution of 25 m. The SAR data were despeckled using a multiple regression method based on the TM scene. The classification of the integrated multi‐sensor dataset was carried out using multi‐layer perceptron neural networks which were trained using ground truth samples taken from test sites within the experimental area. The neural network was used in two separate mapping stages: the first to map nine basic classes of land cover including one of forest, and the second to map eight different types of forest within the generic forest land cover area. The total classification accuracy achieved for the eight forest classes was 77.7% from the integrated TM and SAR dataset, which was 1.7% higher than the accuracy achieved using the TM data alone. Whilst the overall classification accuracy did not improve significantly through the use of SAR data in addition to TM, there were some significant gains for certain individual classes. In particular, the addition of the SAR channel gave a 13.1% improvement in the discrimination of a mixed conifer/broad‐leaf class largely by giving better separation from a pure conifer class.

A comparison of survival rate of the spider Lynyphia emphana WALCK (Araneae: Linyphiidae) among three different types of forest

A comparison of survival rate of the spider Lynyphia emphana WALCK (Araneae: Linyphiidae) among three different types of forest

Conserving the endemic birds on the Comoro Islands, I: general considerations on survival prospects

SummaryThe status of the Comoro endemic birds is briefly reviewed. Field data were gathered during expeditions in 1981, 1983, 1985 and 1989.Some native birds (Cyanolanius madagascarinus, Dicrurus fuscipennison Ngazidja,Treron australison Mwali,Accipiter francesae, Otus rutilus, Leptosomus discoloron Ndzuani,Dicrurus waldeniion Maore) are so rare that they are certainly highly endangered. The altitudinal stenotopy of a few other species makes them also very vulnerable, e.g.Zosterops mouroniensisin the tree-heath zone on Mount Karthala above 1,750 m. A preliminary analysis of habitat preference on Ngazidja suggests a relatively large flexibility of most forest species between different types of forest, including those with altered vegetation structure, but demonstrated their absence in plantations without large trees and/or natural shrubs. Comparison of density of species in Ngazidja and Mwali and an overview of the avifaunal composition on all four islands are the basis for a discussion on colonization history (with possible extinctions), historical change in avifaunal composition, the suitability of each island for the different species and the completeness of their avifauna. The results are checked for possible threats and necessary actions for conservation. Competition by introduced species does not yet seem to be a problem. But importation of foreign animals must be banned and hunting must be regulated (especially for pigeons). Habitat loss (overexploitation of the forest) will soon become a serious problem for the stenotopie forest birds. A suggestion is made for delimiting a national park on Ngazidja and Mwali. Most controversial is the development of tourism. For long-lasting results, education of local people is necessary, together with full liaison with the authorities.

The temporal and spatial analysis of tree age distributions

The temporal and spatial patterns of tree establishment and stand disturbance history are often based on the interpretation of age-class frequency distributions. In particular, the presence of even-aged groups of trees is often used as compelling evidence of past disturbance. However, even-aged groups of trees may be indistinguishable in an age distribution if several different-aged patches occur, especially if their ages overlap. For two different types of forest we used spatial autocorrelation analysis to statistically test for the presence of even-aged patches in tree age data. Ordination and cluster analysis were subsequently applied to a matrix of association measures that reflected both spatial proximity and age similarity to identify even-aged groups of trees. Although the method worked well for our forests, which contained light-demanding tree species, it is likely to be less applicable to forests dominated by shade-tolerant species, because trees may be of many different ages if they were present as suppressed individuals prior to disturbance. However, in these instances the method could be usefully applied in other types of analysis, such as the distribution of growth release dates, tree-fall or fire-scar dates, and growth rates.

Three levels of floristical variation in the forests of Chaco, Argentina

Abstract. This paper analyses the floristic variation in the southern segment of the Oriental Chaco, known as the Santa Fe Forest Wedge. Floristical variation in Chaco forests is described at three levels of scale. On the coarsest scale there is a gradient of increasing floristic richness towards the north, related to a geographic temperature gradient. At an intermediate scale different types of forests are arranged according to environmental gradients correlated with topographic elevation. At a fine scale many microsites can be discerned with different micro‐environments colonized differentially by species. Microsites arise as the result of site‐physiographic history, development of vegetation and the interaction of both and with animals. Several dimensions of regenerationniche variation are distinguished, including canopy and soil characteristics, and propagule dispersal.

Comparative Analysis of Mortality Factors of Artificial Larval Populations of the Gypsy Moth, Lymantria dispar(Lepidotera : Lymantriidae) in Hokkaido : I. Mortality Factors in Five Different Types of Forests

Comparative Analysis of Mortality Factors of Artificial Larval Populations of the Gypsy Moth, Lymantria dispar(Lepidotera : Lymantriidae) in Hokkaido : I. Mortality Factors in Five Different Types of Forests

Role of forest canopies in the collection and neutralization of airborne acid substances

This paper describes the role of the canopy in the collection of airborne acid substances and in the neutralization of the acids by cation exchange processes. Bulk throughfall was collected in three different types of forest in the suburban area of Yokohama. Bulk precipitation was also collected in the open field outside of the forest studied. Samples were analyzed for Ca 2+, Mg 2+, K +, Na +, NH 4 +, H +, Cl −, NO 3 −, SO 4 2, and Al. For almost all components, bulk throughfall exceeded bulk precipitation in elemental flux, owing to interception deposition and canopy leaching. Only the H + flux decreased during passage of precipitation through the canopy. Canopy leaching of Ca 2+, Mg 2+, and K + was determined by assuming that Ca 2+ /Al, Mg 2+ /Al, or K + /Al ratios in interception deposition are equal to the corresponding ratios in bulk precipitation. Total acid deposition to the forest, assumed to be equal to the throughfall fluxes of SO 4 2− and NO 3 −, exceeded the flux of acid substances (H + + NH 4 +) in bulk precipitation by factors of 1.7, 2.0, and 2.5 for Japanese deciduous oak forest, Japanese evergreen oak forest, and Japanese cedar forest, respectively, indicating the importance of interception deposition of acid substances to the canopy. From 49 to 74% of total acid deposition was neutralized at the canopy. A major part of the neutralization was attributable to the cation exchange processes at the canopy surface. Evidently the processes depend on the nature and form of the leaf surface.

The influence of experimental acidification on nutrient release and decomposition rates of needle and root litter in the forest floor

The influence of experimental acidification (diluted H 2SO 4) on mass-loss rates of needle and root litters was investigated in forests of Scots pine, lodgepole pine, Norway spruce and white birch located in a climatic transect through Sweden. Of the two dosages given (32 and 96 kg S ha −1), significant effects on mass-loss rates were observed mainly with the higher dose. When comparing the effect of acid on mass-loss rate of needle litter on all sites together for the whole 3-year period, no effect was seen. By distinguishing the different types of forest and understorey we found a significant general decrease in rate for needle litter of about 8% for the pine forest sites ( n = 10). For the spruce sites ( n = 8) and the birch sites ( n = 2) no significant effects were seen. When considering single sites after 1 year of decomposition, significant effects (rate decrease) were also found for the birch forests. At some spruce sites significant differences in mass-loss rate were seen (both rate increase and rate decrease). When a significant effect was seen its magnitude was found to be dependent on the decomposition rate (soil biological activity) of that site. For root litter the results were less clear. No significance was seen when comparing all sites together or sites of one type of forest. Significant decreases in mass-loss rate after acid treatment were, however, noted for some of the sites after different incubation periods. The patterns of dynamics of the nutrients N, P, S, K and Ca were not affected whereas those of Mg and Mn were and significantly higher release rates were found for these nutrients after acid treatment. The release rates of the nutrients N, P, S, K and Ca from litter were proportional to litter mass-loss and for the Scots pine stands this meant a decreased release rate for these nutrients.

Density and Species Richness of Some Forest Bird Communities in South Sweden

Eight forest plots were studied, some of them for five years. Bird community population densities fluctuated from year to year, but the density differences between habitats remained approximately the same. Densities and bird species richness of different forest plots were closely correlated. Both bird community densities and species richness were most successfully predicted from the proportion of the basal tree and shrub area standing dead. Vertical foliage structure and/or number of species of trees and shrubs were minor additional factors. It is suggested that vertical foliage structure is correlated with ecosystem productivity. Food availability is suggested as the ultimate determinant of variations in local bird species richness and community density. The proportion of Turdinae decreased and that of Sylviidae increased with increasing total bird population density. Overall, the bird community structure in different types of forests was similar. The proportion of residents was higher and tropical migrants lower in coniferous than in nearby deciduous forests. Only about 10% of the bird individuals in the coniferous forests were tropical migrants in contrast to about 60% in northeastern North America.

Behaviour of the army ant Eciton burchelli westwood (Hymenoptera: Formicidae) in the Belém region. I. Nomadic-statary cycles

This paper is the first of a series on the behaviour of Eciton burchelli Westwood. Some observations on Eciton hamatum Fabricius are added. The study took 2 years and was carried out in a forest reserve at the Instituto de Pesquisa e Experimentação Agropecuárias dp Norte (IPEAN), Belém, State of Pará, Brazil. All the movements of E. burchelli and E. hamatum colonies were mapped. Colonies were observed in different seasons and in different types of forest. For six E. burchelli colonies 34 Nomadic-Statary cycle (NSC) durations were recorded giving the lengths of the Nomadic Phase (NP) and Statary Phase (SP). Five NSC, NP and SP durations of one E. hamatum colony were recorded. The data confirm the existence of endogenous cycles of activity in these ants and suggest that they have a basically uniform periodicity over a very wide area (Panama to Belém).

Population studies of Malaysian primates

Systematic field studies on the abundance of primates were made in five different types of forest in West Malaysia in 1970. Primate groups of 7 species were seen on 97 occasions during 527 hours of field observations. Secondary forests had the greatest primate density of any of the natural forest habitats surveyed. Estimated primate group densities varied from less than 4 groups per square mile to 40, with an average of 7.2 groups per square mile. The most abundant species was the banded leaf monkey (Presbytis melalophus) with 2.95 groups per square mile, followed by the long-tailed macaque (Macaca fascicularis) with 1.54 groups. Primary forests had a lower density which varied from less than 2 groups per square mile to 15, and averaged 5.9.P. melalophus was again the most abundant species with an average of 2.22 groups per square mile, followed by gibbons (Hylobates lar) and siamangs (H. syndactylus) each with 1.11.M. fascicularis averaged only 0.37 groups per square mile in primary forests. Primates were unexpectedly rare in mangrove forests and rubber plantations. Twenty-four primate groups were found in urban forests and parks. Twenty of these groups wereM. fascicularis, 3 were silver leaf monkeys (P. cristatus) and 1 was the dusky leaf monkey (P. obscurus). In urban areas,M. fascicularis groups varied from 7 to 44 individuals per group, with an average of 24. A great need exists for increased scientific and conservation attention for the primate populations of Malaysia.

Leishmaniasis in Brazil. VI. Observations on the seasonal variations of Lutzomyia flaviscutellata in different types of forest and its relationship to enzootic rodent leishmaniasis (Leishmania mexicana amazonensis).

Abstract The seasonal fluctuation of Lu. flaviscutellata is shown to be closely related to rainfall, the population of this species declining during the rainy season, between May and March, and increasing again during the dry season, reaching a peak towards December and January. A comparison of the numbers of Lu. flaviscutellata caught in different types of forest showed that this species is more common in the wetter forests of the “igapo” than in the drier “terra firme” forests, although similar seasonal fluctuations are noted in both types of forest. The close correlation between the numbers of Lu. flaviscutellata and the incidence of initial infections of Leishmania mexicana amazonensis in Oryzomys capito indicates that the major factor controlling the incidence of leishmaniasis is the number of sandflies.

Sikring av ulike skogtyper

The author presents a comprehensive list of different types of forests, groves, and single species which are preserved, or singled out for preservation, and puts forward the case for an additional list of occurrences worthy of conservation. So far preservation has been largely dependent on state ownership of land and planning has been unsatisfactory mainly because executive organs have been understaffed. It is argued that Norway's exceptionally favourable maritime climate makes it desirable to have a good coverage of marginal northerly occurrences. An ample selection of examples should also be aimed at both from the East-West and from the vertical vegetational zonings.

An avifaunal study in different types of forests in the central part of Hokkaido, Japan

An avifaunal study in different types of forests in the central part of Hokkaido, Japan

Physiochemical characteristics of soil in tropical sal (<i>Shorea robusta</i> Gaertn.) forests in eastern Nepal

The physiochemical properties of soils of two different types of forests (pure Shorea robusta and mixed Shorea robusta) were analyzed. Soil samples were collected from both types of forest and analyzed for texture, pH, organic matter, humus content, water holding capacity, nitrogen, phosphorous and potassium. In both the pure and mixed forest, soil was sandy loam (60.12% and 50.58% sand, 28.59% and 35.24% silt and 11.12 and 22.41% clay, respectively). The pH value was lower in pure forest (4.33) than in the mixed forest (5.26), and so were phosphorus and water holding capacity. The higher values of humus, organic matter, nitrogen and potassium (7.34%, 2.42%, 0.117%, 267.73 kg/ha, respectively) were found in pure forest. The higher levels of soil nutrients in the pure forest were due partly to reduction in the loss of top soil and partly to the increased supply of nutrients in the form of leaf litter and biomass from the larger number of sal trees and their saplings.
 
 Key words: Shorea robusta, soil texture, nitrogen, soil pH, Udayapur
 
 Himalayan Journal of Sciences 1(2): 107-110, 2003