Showing papers on "Tree canopy published in 1970"

Jacquinia pungens, a Heliophile from the Understory of Tropical Deciduous Forest

Abstract: The general ecology of the understory shrub Jacquinia pungenis is described, with special reference to its behavior of bearing leaves during the dry season (when the overhead forest canopy is deciduous) and being deciduous during the rainy season. The bush is restricted to those stages of lowland deciduous forest succession ranging from 10 to 50 years of age; it appears to starve to death or be competitively excluded from habitats where it is continuously insolated, and from older or wetter forest where it does not receive enough sunlight owing to light obstruction by the deep canopy during the dry season. As expected for a plant that is vegetatively active during the dry season, the plant is especially well protected from herbivores by needle-tipped leaves and toxic compounds in the foliage. Effectively, J. pungens has invaded a seasonally available prairie and has the bush life form characteristic of woody plants in such well-insolated habitats. ALMOST ALL NON-RIPARIAN woody plants in Central American deciduous tropical forest bear leaves during the rainy season and are leafless or vegetatively dormant during the major dry season (January-April). An obvious way for a plant to avoid the intense interspecific vegetative competition of such a forest habitat is to bear leaves during the dry season and to be deciduous during the rainy season. A shrub, Jacqiinita pungens A. Gray (Theophrastaceae), does this and is thus important in illustrating how the number of species in a habitat can be increased through the invasion by a species that uses resources unused by other members of the

Number and spacing of rainfall-gauges in a deciduous forest stand

Abstract: The purpose of the study was to determine the representative number of rainfallgauges for measuring rainfall under a forest canopy and to establish spacing of these gauges. The experiment was made in 1963 in a deciduous stand in Bialowieza Primeval Forest (Poland). The result showed that it is desirable to use at least 30 rainfall-gauges and that measurement of rainfall does not, practically speaking, depend on the spacing of these gauges when they are arranged in a regular network.

Tropical peatland tree-species diversity altered by forest degradation.

Abstract: Astiani D. 2016. Tropical peatland tree-species diversity altered by forest degradation. Biodiversitas 17: 102-109. Indonesianexperienced relatively high deforestation and degradation. The forests degradation could bring the forests into a temporary or might bepermanent destruction not only in forest vegetation density and structure, but also in species composition. A study had been carried outto examined the impact of peatland forests degradation on their species diversity composition in Ketapang, West Kalimantan peatlandforest. Stratified random sampling was used to distinguished forest degradation class (low, intermediate and high degradation levels)Â based on the differences in spectra image and confirmed with field checking by measuring forest canopy opening to measure thedegradation levels. Six to twelve of a 20x100m plots were established to sample tree structure and composition distributed alongpeatland landscape. All trees species diameter >5cm was registered an species identified. Results indicated that tree diversity wassignificantly reduce due to forest degradation, in low, intermediate, and high degraded forest were 82, 72, and 48 consecutively. Forestdegradation is not only resulted more than 50% of important species loss in high degraded peatland forest but also reducing ~40% treeabundance. Ten species were found in high degraded forest, e.g., Calophylum inophyllum, Cyathocalyx biovulatus, Neoscortechiniakingii, and Eugenia cerina, were not present in low degraded one. The species composition and abundance shifting due to forestdegradation should be considered on peatland forest management to hinder permanent species loss.

The radiation budget of a forest canopy.

Abstract: Models were developed to separate the radiation-transfer processes of plant canopies from those of the underlying soil surface. The effect of the canopy was then examined by applying the model to springtime measurements of the fluxes of short- and longwave radiation entering and leaving a pine plantation. The model showed that 10 percent of the shortwave radiation that was absorbed within the canopy and 20 percent of that leaving the upper canopy boundary originated as reflection from the forest floor. Longwave radiation emitted upward by the canopy during the daylight period exceeded that emitted downward by about 6 percent. The model confirmed the importance of the longwave component to net radiation of the canopy.

An Energy Budget Study Above the Forest Canopy at Marmot Creek, Alberta, 1967

Abstract: For a 19-day period in July 1967, daily estimates of evapotranspiration were obtained from hourly calculations of the Bowen ratio above the forest canopy. The estimates ranged from 7.9 mm to 1.5 mm. The Bowen ratio was found to be very dependent on wind direction, sky condition, and basin aspect, which was a significant factor. Although the area is unhomogeneous, the results appear reasonable when compared with other estimates of evapotranspiration.