Showing papers on "Undergrowth published in 2003"

Activity and habitat use of lesser mouse-deer (tragulus javanicus)

Abstract: Activities and habitat use of lesser mouse-deer (Tragulus javanicus), a common but poorly studied ruminant native to lowland tropical forests of Southeast Asia, were investigated by full-day radiotracking and direct visual observations in the Kabili-Sepilok Forest Reserve, Sabah, Borneo. The mouse-deer was thought to be nocturnal, but diurnal distance moved per hour and behaviors observed directly in wild mouse-deer indicated that they were mainly active during the day and rested at night. Active individuals foraging or moving from shelter to shelter were mainly observed during the day, and inactive individuals resting on open forest floor were mainly observed during the night. Captive mouse-deer observed in a farm enclosure (1.5 ha in size) also showed activities similar to those observed in the forest. Radiotracking for 24 h revealed that mouse-deer significantly preferred crown-gap areas with dense undergrowth of creeping bamboo (Dinochloa) during the day but that they tended to move to the higher and drier ridge areas at night. These results indicated that mouse-deer used crown-gap areas as foraging sites and ridge areas as resting sites. Our results strongly suggest that mouse-deer use food resources in gap areas in tropical forests. Key words: activity, Borneo, gap, habitat use, home range, mouse-deer, Tragulidae, Tragulus javanicus, tropical forest

Forest canopy density stratification using biophysical modeling

Abstract: Forest canopy density is an important parameter to assess the ecological conditionsviz, light penetration through canopy, undergrowth, surface reflectance, rainfall interception, etc. in a forest landscape. The rate of change in the cover and density has increased due to human need for fuel and fodder. Hence, quick, repetitive and accurate information about forest density is required at the local, regional, state and national levels for sustainable forest management. Satellite remote sensing has the potential to provide information on the forest canopy closure. The present study aims at forest canopy density mapping using satellite remote sensing data using three techniques: visual interpretation (VI), object oriented image segmentation (OOIS) and biophysical modeling (BM). On comparing the techniques, the BM has been found to be the better density mapping technique than other two in terms of accuracy, efficiency and high correlation with ground estimates.

Nature conservation and grazing management. Free-ranging cattle as a driving force for cyclic vegetation seccession

Abstract: Key-words : biodiversity, herbivory, wilderness, non-linear dynamics, mosaic cycling, grassland, wood encroachment, forest, Bos taurus , Calluna vulgaris , Deschampsia flexuosa.This thesis examines the suitability of controlled and wilderness grazing as conservation management tool for open, nutrient-poor habitats. It tests the Resource-mediated Successional Grazing Cycle (RSGC) theory, which claims that free-ranging large grazers can act as driving force for successional woodland-grassland cycles. The hypotheses were that free-ranging cattle create grassland in woodland (i), deplete the nutrient pools of these grasslands (ii), induce invasion of woody pioneers because of this depletion (iii). During the subsequent woodland phase the soil nutrient pool is replenished (iv). The study was carried out in the Wolfhezerheide, The Netherlands. The vegetation was composed of 19 ha of woodland, 33 ha of grassland and 9 ha of Calluna heathland. The area was year-round grazed by free-ranging cattle (90 kg ha -1 yr -1 ) after 1983. Atmospheric N-deposition varied from 25-60 kg ha -1 yr -1 depending on the vegetation. Vegetation change was monitored. Habitat and diet selection were quantified by 24-h observation and bite counting. On the basis of these data, nutrient balances were assessed for the whole area, the successional communities and excreta and excreta-free patches in the grassland. The results showed that cattle induced grasslawns in gaps in the heathland and woodland. They suppressed woody and tall herbaceous species in the woodland undergrowth and introduced grass seeds by dung deposition. Nutrient removal only exceeded the atmospheric inputs on excreta-free patches in the grassland for phosphorus and potassium. Nutrients were removed from these sites by off-take and gaseous excreta-N losses. Cattle also reduced the interception deposition. Nutrient depletion favoured the invasion of pioneer dwarfshrubs ( Calluna ) and trees ( Pinus sylvestris and Betula spp ) in the grass lawns. This result was related to the carbon-based chemical resistance of the involved woody pioneers. Cattle and wild herbivores only prevented wood encroachment on relatively nutrient-rich grasslands. Wood invasion and abandoning by the cattle induced replenishment of the soil nutrient pool. The results confirmed the RSGC hypotheses and emphasised the interaction of herbivory and plant resources as determinants of cyclic plant succession. These findings implicate that wilderness grazing may generate temporary open, nutrient-poor habitats in dry uplands, but incompleteness of the abiotic gradient, successional mosaics and herbivore assemblage will restrict the openness and soil depletion. Under these circumstances, conservation managers might prefer controlled grazing. Forced summer grazing, nutrient removal from grass lawns by housing of the animals during the night and additional removal of unwanted species seemed to mimic natural herbivory.

Pseudoescorpiões (Arachnida) da vegetação de sub-bosque da floresta primária tropical de terra firme (Coari, Amazonas, Brasil)

Abstract: A richness of 15 pseudoscorpion species, 12 genera belonging to 5 families (Chthoniidae, Geogarypidae, Olpiidae, Atemnidae and Chernetidae) were found in the undergrowth vegetation of the dryland forest, at the upper Urucu river, Coari, Amazonas, from 1991 to 1996, and was collected by the "beating tray" method. Apolpium aff. vastum was the most frequent and abundant species in the undergrowth forest vegetation. Among the various types of plants examined, the majority of the pseudoscorpions occurred in small palms (in the ground-trenched palms as much as the erect stemmed palms). To appraise the specie's composition of these arachnids found in the different kinds of plants, the Q-mode analysis was used based on Jaccard's similarity coefficients. The coefficients that showed the greatest similarity were between the fauna of the palms and other plants that accumulate litter on top of the ground, and between the Bromeliacea and Aracea of the floor and other plants that use the litter of the ground.

Study of the biomass and productivity of Cinnamomum camphora plantation

Abstract: The results show that the estimated biomass of Cinnamomum camphora plantation is 111.08 t·hm~(-2); the productivity is 6.17 t·hm~(-2)a~(-1). The distributing sequence of the biomass of the plantation ecosystem is that tree stratum>litter>undergrowth>herb. The total biomass of tree layer is 91.97% t·hm~(-2); its net productivity is 5.11 t·hm~(-2)a~(-1). The distributing sequence of the organic biomass of the tree is that trunk>branch>root>bark>leaf. Regarding the production structure, the biomass of trunks under the height of 5 m accounts to 80% of the total; the biomass of branches between 4 m and 11 m accounts to 86% of the total; the biomass of leaves between 8 m and 12 m accounts to 78% of the total; and the biomass of roots below the ground level of 40 cm accounts to 84.74%. The present stage structure of the community is irrational. The structure of productivity should be regulated so as to improve the integrate effects of the community.

Seasonal and diel activity of Ixodes ricinus (Acari: Ixodidae) subpopulations in Denmark. Aspects of size, physiological age, and malate dehydrogenase genotype in a forest site without any undergrowth

Abstract: The underlying population dynamics and the behavioural patterns of the vectors are key issues in understanding the transmission of vector borne pathogens. For the tick Ixodes ricinus both seasonal and diel activity have been described as bimodal patterns, which in seasonal aspect has been interpreted as representing two cohorts. However, recent studies have shown that this interpretation may be incorrect. The aim of this study was to obtain more detailed information on nymph host seeking by studying subpopulations of ticks during the day and season. The study was designed to allow for comparisons of the diel variation and seasonal variation in their dependency in a number of tick characteristics. The study took place in a forest with planted beech trees without any undergrowth. Ticks were collected by flagging the dead leaves on the forest floor. For each nymph, a number of visual observations were made. The size and physiological age was observed and the nymphs were genotyped in the malate dehydrogenase locus (MDH, E.C. 1.1.1.37). Briefly the main results can be given as: (i) There were significant differences in the composition of size classes during the season, but only limited trends in time. (ii) The proportion of the small nymphs was highly variable, with a variation from 3% to 24% in October and September, respectively. (iii) The diel variation in MDH genotypes was significant in May and August. (iv) Nymph size classes and physiological age appeared to interact. The non-random interaction was caused by a relatively even distribution of small nymphs in all four age classes, while large nymphs tended to fall into age class 2 and 3. The length by age interaction for the individual months was noted to be significant in May, July, August and September, but not in June. Similarly the interaction was significant in the morning and afternoon, but not at midday. The overall results describe the seasonal and diel activity patterns as changing systematically for several characteristics under the influence of weather condition and population dynamics. In conclusion: The observations are best interpreted as being produced of a single cohort of ticks, but the revealed complexity of the host seeking activity suggest that measures of activity × abundance should be interpreted very cautiously in relation to population dynamics.

Vegetation Dynamics and Biomass Production of Undergrowth Vegetation in Eucalyptus tereticornis Plantation

Abstract: The present study deals with phytosociology and biomass production pattern of undergrowth vegetation in Eucalyptus tereticornis plantation in Hardwar Forest Division, situated in Ganga basin. The total number of plant species were recorded as 56, 39 and 32 during rainy, winter and summer season respectively. Cannabis sativa was dominating the community by having maximum value of Importance value index and co. dominating by Ageratum conyzoides . The maximum biomass production of undergrowth vegetation was recorded during rainy season and minimum during summer season.

Rich Biota in the Forests of Yanbaru, Northern Montane Part of Okinawa Island, Japan, and Imminent Extinction Crisis of the Endangered Species

Abstract: Yanbaru, the northern montane portion of Okinawa Island, has historically been dominated by evergreen bloadleaf forests with remarkably rich biota, but many parts of the forest are now being destroyed as a result of government policy. Although there are many endemic animals and plants in the remaining natural forests, many of them are now in imminent risk of extinction. The status of populations of vertebrate animals listed in the Red List is described. Species diversity in Yanbaru forests is possibly highest among all Japanese forests, and this may be a dominant cause of the evolution and maintenance of many endemic species. However, the diversity has been diminished by forest cutting and removal of forest undergrowth by government subsidies. Suspension of clear-cutting and undergrowth removal, and change of proposed helipad sites from natural forest areas are necessary to preserve the unique biota of this area.

EFECTO DE LA VEGETACIÓN ASOCIADA AL SOTOBOSQUE SOBRE EL CRECIMIENTO Y DESARROLLO INICIAL DE Abies religiosa (HBK.) Schltdl. et Cham.

Abstract: At early stages, fir trees stay in the undergrowth for several years, during which they grow slowly and develop characteristics of shadow tolerant species.

Microecosystem Analysis of the Structure and Functions of Forest Biogeocenoses

Abstract: The “microecosystem” approach and an adequate system of quantitative methods have been used to study the relationship between the chorologic changes in the structure and functions of edificator tree stand and other components of the pine (Pinus sylvestris L.) forest cenoecosystems of the Transural and Northern Turgai regions. Significant correlations of the density of pine undergrowth with the litter thickness; of its growth with root competition, stand closeness, and, to a lower degree, photosynthetically active radiation (PAR); and of the numbers of small mammals and groups of soil mesofauna with herbaceous phytomass have been found. The possibility of the synthesis of population-ecological, synecological, and biogeocenological methods has been demonstrated.

Species Diversity in Undergrowth of Artificial Forests on Lower Hilly Land

Abstract: Artificial pure forests of Pinus rigida var. serotina, P. elliottii,Eucalyptus robusta,Schima superba, Liquidambar formosana,and mixed forests of L. formosana / P. massoniana or P. elliottii,which were planted in 1991 in seriously disturbed lower hilly land in Taihe county, Jiangxi Province, were investigated after 10 years. Changes of species diversity in the restored vegetation were measured. Before afforestation there were only 7 species such as Setaria viridis,Arundinella hirta,Rosa laevigata and Smilax china. In 1993 and 2001, the number of species increased to 21 and 58, respectively. In condition of the same density of plantation, the species diversity in the vegetation of the plantations was high in pure conifer forest, followed by conifer broadleaved mixed forest and broadleaved pure forest. The effects of afforestation species, stand structure (pure or mixed) and especially stand density on species diversity were obivious. However, conifer forest was poor in water holding, the soil under which had lower content of organic matters. Conifer broadleaved mixed forest is best for maintenance and restoration of species diversity and for improvement of soil and ecological environment.

Quantitative dynamics and phytodiversity of undergrowth in forests of bangladesh

Abstract: Doi: 10.4038/jnsfsr.v31i1-2.3034 J. Natn. Sci. Foundation Sri Lanka 2003 31(1&2): 215-229 Proceedings of the South and Central Asian MAB Meeting of Experts on Environmental Conservation, Management and Research, Hikkaduwa, Sri Lanka 15-18 October 2002

Clonal growth and clonal morphology of potentilla reptans var. sericophylla in forest understorey and gap

Abstract: A reciprocal transplant-replant experiment was carried out to investigate clonal plasticity and local specialization of forest gap population and forest undergrowth population of a stoloniferous herb Potentilla reptans var. sericophylla in the Pinus tabulaeformis forest at Dongling Mountain, Beijing. The experiment was conducted from 19 Mayto 23 August 1996 in Dongling Mountain (115°26' - 115°30' E, 40°00' -40°02' N), 114 km southwest of Beijing. At the beginning of the experiment, one forest gap population and one forest undergrowth population of Potentilla reptans var. sericophylla in the Pinus tabulaeformis forest was selected, In each population, 120 ramets of Potentilla reptans var. sericophylla were selected at random as target plants. Target plants experienced one of four treatments during the experiment. 1) Half of the target ramets in the forest gap population were transplanted to the forest understorey. 2) The other half in the forest gap was replanted in their native site. 3) Similarly, half of the target ramets in the forest undergrowth were transplanted to the forest gap. 4) The other half in the forest understorey was replanted in their native site. The distance between the two field experiment sites was about 100 m. The gap was about 15 years old. During the experiments, the experimental plants all grew naturally. There were three times of harvesting on 23 June, 23 July and 23 August, 1996. hi each of the harvests , 20 target ramets were chosen randomly and harvested for each of the treatments. The genet biomass, ramet number, blade length, blade width, petiole length, stolon internode length and total stolon length were measured after each harvest to investigate clonal plasticity and local specialization. A One-way and a Two-way ANOVA, with the native habitat and the growing habitat of the experiment plants as the main effects (GLM procedure, SAS), were applied for analyzing responses in all measured characters. The results show that the biomass, number of ramets and total stolon length of the experimental plants under the forest undergrowth was smaller than those under the forest gap. Petiole length, leaf blade width, leaf blade length and internode length did not differ between the different growing habitats. The plants from the forest gap grew better than those from the forest undergrowth. These results indicate that there was no local specialization in the plasticity of characters related to clonal growth and clonal morphology in forest gap and forest undergrowth. Clonal plasticity rather than local specialization is the main strategy of P. reptans var. sericophylla in heterogeneous habitats.

Study on the Undergrowth Plant Diversity of Eucalyptus Plantation in Leizhou Peninsula

Abstract: This paper makes an investigation as well as a study of the undergrowth plant diversity and biomass of eucalyptus plantation in Leizhou Peninsula. The result indicates that the undergrowth plant diversity and biomass of eucalyptus plantation are mainly related to the soil type of the forest stand and the forest canopy density. The growth of the undergrowth plants varies with the age of the forest and the degree of the forest canopy density. There is no remarkable difference of species richness, diversity and biomass of the undergrowth plants between different kinds of eucalypti,and between eucalypti and other kinds of acacia. The low diversity of the undergrowth plant of eucalyptus plantation is not caused by the eucalypti themselves.

Biomass Allocation in Mixed Forest of Cunninghamia lanceolata and Tsoongiodendron odorum

Abstract: The biomass and its allocation in mixed forest of Cunninghamia lanceolata and Tsoongiodendron odorum and pure forest of Cunninghamia lanceolata in midsubtropic were studied The stand biomass in mixedforest is 129 times of that in pure forest, and the proportion of stratum layer in stand biomass of mixed stand were higher, and that of undergrowth were lower, than that of pure stand In mixed forest, the height of functional crown of Cunninghamia lanceolata was higher than that of Tsoongiodendron odorum, though they intercrossed each other Compared to pure forest, the functional crown of mixed forest was 4 m thicker and the proportion of live branches and leaves were higher, which manifested that mixed forest had higher efficiency in utilization of radial energy In either mixed or pure forest, the vertical distribution for coarse roots of Cunninghamia lanceolata showed single apex, and the fine roots presented a trapezium or singleapex type; for Tsoongiodendron odorum, the distribution of coarse and fine roots both had two apices In mixedforest, coarse roots of both Cunninghamia lanceolata and Tsoongiodendron odorum were enchased each other, while both fine roots were concentrated at surface soil and were isolated from each other at deep soilCompared to mixed forest, the layer with maximum coarse roots was higher, and that with maximum fine roots was lower, for Cunninghamia lanceolata in pure forest

Forest resource conservation for biodiversity through Kyusei Nature Farming.

Abstract: The cooperation project on the forest resource conservation for biodiversity between the Thai Royal Forest Department and Sekai Kyuseikyo Thai Headquarters, Saraburi province. During 1999 2001, the Kyusei Nature Farming was applied to the national reserved forest (lower mixed deciduous forest type) to increase the forest biodiversity, simultaneously with the intensive forest fire protection. The preliminary study revealed that EM technology was progressively introduced to the forest ecosystem, the species diversity were increased especially the undergrowth such as herbs, ferns, rattans and mushrooms, also the fauna such as amphibians, reptilians, avians and