Ha Of Woodland Research Articles

Prediction of species richness of breeding birds by landscape-level factors of urban woods in Osaka Prefecture, Japan

We examined some models to predict the species richness of forest birds by the landscape-level factors at urban woods in Osaka Prefecture, Japan. The environmental factors examined were area (A) and elongation (E) of woodlands, the distance to mountain (D), distance to the nearest woods (> 10ha) (D 10), and the proportion of woods (Pw) and field (Pf) within 25 km2 outside the parks. The species–area relationship at 28 parks was better fitted by the power function (r2=0.704) and by the logistic function (r2=0.696) than by the exponential function (r2=0.637). A woods that was planted 7 years ago had extremely few species, but there was no significant difference in species richness between woods < 50 years old and those older. We built Principal Component Regression (PCR) models to predict the species richness, because collinearity was detected between D and Pw. PCR, log[S/(43−S)] = −1.820 + 0.224logA − 0.0113 D + 0.133 logPw − 0.0588E (R2 = 0.939, n = 27) was estimated. The species–area relationship was caused by difference in the occurrence pattern of bird species. This was attributable to the differences in feeding habit or micro-habitat use. We estimated that birds living between the forest interior and the edge, such as Dendrocopos kizuki, required at least 20 ha of woodland.

Land use, deforestation and reforestation in the Zambian Copperbelt

AbstractTemporal and spatial changes in land use, vegetation cover, deforestation and reforestation in the Zambian Copperbelt were studied using a combination of aerial photograph analysis, literature review and inquiries among relevant government institutions.The study showed that between 1937 and 1984 loss of natural woodlands in the Copperbelt of Zambia (total area of Copperbelt: 9,615 km2) amounted to 41 per cent woodland area (8,419 km2). The major causes of this deforestation are woodfuel collection (for firewood and charcoal), cultivation and replacement of natural woodland with forest plantations. These accounted for 38 per cent, 37 per cent and 15 per cent of the total deforestation, respectively. Before 1962 the copper mining industry used large quantities of firewood to generate electricity and this resulted in the loss of 150,413 ha of woodland between 1937 and 1961. When the mining industry switched to hydroelectricity, urban households became the major users of woodfuel. The urban population in the Copperbelt increased from 0.412 million in 1960 to 1.400 million in 1984 and its consumption of woodfuel led to the deforestation of at least 89,436 ha between 1962 and 1984.Deforested areas are left to regenerate naturally. However, due to poor management about 34 per cent of the area deforested before 1962 has failed to regenerate. Although 50,200 ha have been reforested with exotic trees, only 5,020 ha of this is on land previously deforested. Thus only about 10 per cent of reforestation efforts have contributed to the rehabilitation of damaged land. Ninety per cent of the reforestation has actually replaced standing indigenous woodland.Uncontrolled bushfires have destroyed forest plantations and have also caused the failure of woodland regeneration in deforested areas. These observations indicate that if forest resources in the Copperbelt of Zambia are to be properly managed it will be necessary: to effectively regulate land use changes and; to control bushfires.

Woodland structure, destruction and conservation in the Copperbelt area of Zambia

Abstract Between 1937 and 1983 a total of 391 400 ha of woodland, representing 51% of the 768 900 ha in the Zambia Copperbelt, had been deforested for industrial and household woodfuel. This has occurred in spite of a forest reservation programme that increased the area in forest reserves from 31 707 ha in 1942 to 252 715 ha in 1965. Between 1965 and 1980 the reserved forests were reduced to 246 930 ha and since then the area has remained static. The rapidly growing demand for charcoal by the increasing urban population, and the growing problem of acid dust and rain pollution from copper smelters, pose serious threats to forest conservation in this industrial region of Zambia. Current forest conservation is restricted to the establishment of exotic forest plantations and recently deforested areas are left to regenerate naturally. Forest destruction and conservation in the Copperbelt area were studied and the structure of old-growth and coppice woodland stands at 9 and 14 sites, respectively, investigated during 1982–1984. The Copperbelt vegetation is dominated by Brachystegia-Julbernardia woodland. Mean species diversity of 24·40·1 ha −1 in coppice stands was higher than that of 18·9 found in old-growth stands. Stem density in coppice was 3·3 times that observed in old-growth woodlands. The majority of species (over 50%) in both old-growth and coppice were represented by less than 11 stems per sampling plot. Mean basal area at breast height in coppice aged 19–23 years was 14·33 m 2 , which was 95% of the mean basal area of 15·15 m 2 found in old-growth woodlands.

Sheep-Grazing with Different Foraging Efficiences in a Dutch Mixed Grassland

(1) In 1972, 11 ha of woodland, heathland and previously manured pasture was fenced in for a sheep-grazing experiment. The different grazing intensities in the grassland area were quantified, since it is considered a prerequisite for the establishment of heterogeneous vegetation patterns, i.e. closely grazed areas, roughness and shrub. (2) Grazing intensity, implying associated effects of treading and dunging (occupancy), can be estimated by dunging intensity. Grazing intensity implying the defoliation by animals can be estimated using exclusion cages. Despite the fact that both methods show a degree of inaccurancy they seem appropriate for nature conservation purposes. (3) Peak standing crop (including standing dead material, but excluding litter) reached 210 g m-2 in Leontodon autumnalis, 420 g m-2 in Holcus lanatus, 510 g m-2 in Agrostis capillaris, 730 g m-2 in Agrostis stolonifera, 830 g m-2 in Juncus acutiflorus, and 1130 g m-1 in Juncus effusus communities in October 1981. (4) Grazing intensity expressed as efficiency of foraging was 0.89 in Leontodon autumnalis, 0.30 in Holcus lanatus and 0-09 in Agrostis capillaris communities over a 6 month period from June to November 1981. (5) Low species diversity was related to very low efficiency of foraging, whereas species diversity was relatively high for foraging efficiencies ranging from moderate to high. (6) Grazing at an average stocking of 3 sheep ha-' resulted in a smaller area (13%) with a short turf ( 36 cm), and a much larger area (69%) with intermediate turf. (7) Measurements of foraging efficiency can enhance the ideal situation in which authorities in charge of management, knowing the herbage accumulation, could indicate preferred proportion of structural components and then determine the appropriate stocking density.

Seasonal Timing, Geographic Distribution, and Flight Behavior of Broad-Winged Hawks During Spring Migration in South Texas: A Radar and Visual Study

Seasonal Timing, Geographic Distribution, and Flight Behavior of Broad-Winged Hawks During Spring Migration in South Texas: A Radar and Visual Study

Regeneration of Oak-Birch Woodland Following Exclusion of Sheep

(1) Sheep have been excluded for 26 years from 1. 12 ha of woodland dominated by Quercus petraea, Betula pendula and B. pubescens in which there had been no regeneration of oak for at least 50 years and only limited regeneration of birch. (2) Outside the enclosure there is still no regeneration and the field-layer has remained a closely grazed sward of Deschampsiaflexuosa. (3) Inside the enclosure D. flexuosa has grown taller and Vaccinium myrtillus has greatly increased both in cover and in height. (4) Seedlings of Betula spp. are plentifpl every year in the grazed field-layer but most are rapidly destroyed; they are almost absent from the ungrazed field-layer. A proportion of those present within the enclosed area in 1955-56 have survived and are now saplings 1-4 m tall but there is no evidence of subsequent recruitment. (5) Seedlings of Quercus petraea occur both inside and outside the enclosure in those years following large crops of acorns. Outside they are destroyed but inside a proportion of each crop survives to give successive recruitments to the population of saplings. (6) Adequate regeneration of Q. petraea has been achieved simply by excluding sheep. The tallest saplings are now 4-5 m high. There is no evidence that climatic or edaphic conditions are seriously inhibitory. (7) Oak has regenerated both in gaps and beneath the canopy of oak so that, with protection, the proportion of oak is likely to continue to increase and that of birch to decline. (8) Brown podzolic soils and humo-ferric podzols persist both inside and outside the enclosure but the humose horizons inside have become much less compact and contain higher densities of fine roots and mycorrhizae of the trees. This may increase growth rate and reduce mortality of the trees.

Coyote Movements, Habitat Use, and Food Habits in Southwestern Oklahoma

Coyote Movements, Habitat Use, and Food Habits in Southwestern Oklahoma

Wpływ zmiany struktury wiekowej i dodatkowego pokarmu na dynamikę liczebności populacji dzików

Studies were made from 1965-1970 within the Kampinos National Park forests near Warsaw and surrounding area, for the purpose of ascertaining the possibility of limiling the amount of damage caused by wild boar, Sus scrofa Linnaeus, 1758 on commercial land. W latach 1965-1970 na terenie około 2.500 ha lasów północno-wschodniego krańca Puszczy Kampinoskiej i na przyległych do niej terenach polnych przeprowadzono badania mające na celu ocenę możliwości ograniczenia szkód powodowanych przez dziki na uprawach rolniczych przy pomocy działania na strukturę wiekową i sytuację troficzną populacji.