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Mahogany (Swietenia marcophylla is widely regarded by conservationists as on the verge of extinction. However, throughout most of its range, it is generally regenerating well within virgin and logged forest, and is a good colonizer of abandoned farm land. It thrives on disturbance and, outside its natural range, is a good plantation tree.
Zoosporic and conidial fungi species and environmental factors in 10 various sites of River Narew in the Narew National Park were studied. Samples of water were collected in autumn 1999 and spring 2000 for hydrochemical analysis and the order to determine the number of fungal species. Buckwheat-seeds, hemp-seeds, cellophane and snake exuviae were used as bait during the exposure in laboratory. 198 lower aquatic fungus species were found in various sites of River Narew. 13 species were recorded for the first time from Poland.
Coastal resource utilization and management systems, both traditional and more recently conceived, were studied in Mecúfi district, northern Mozambique in a post-conflict situation prior to which a significant migration of people to the coast had occurred. A wide variety of coastal biotopes containing a multitude of resources had been affected in various ways. Intertidal organisms exhibited signs of decreasing abundance and average size, whereas offshore fishes and mangrove forests did not show signs of over-utilization. It was observed that traditional coastal management systems were still influential, but that newer initiatives were only beginning to enter into significant dialogue and cooperation with these. In the current circumstances of peace and political stability, the principal threat to coastal management and the interests of local people in Mecúfi is considered to be potential loss of common property resources and land tenure in the face of prospects of privatization, but Mozambican authorities are presently addressing these issues with legal reforms.
A coastal forest planted nearby the sea can provide many shelter benefits for the coastal regions. It is ideally if the continuity of the shelter benefits could be preserved through reasonable management. Thinning and regeneration as the most important management techniques for plantations can help the continuity of the shelter benefits of the coastal forest. However, because of the peculiarities of coastal forest, i.e., the coastal plantation nearby the sea is vulnerable to disturbances (thinning as one kind of disturbance), the study on thinning and regeneration within a coastal forest is poorly understood. The purpose of this paper is to give a primary understanding in natural regeneration for the coastal Pinus thunbergii forest with different thinning rates after four growing seasons since thinning. The experiment was carried out at the middle of the shoreline along the Japan Sea, and the investigated sites consisted of four thinning treatments (control, 0% thinned, 20% thinned, 30% thinned and 50% thinned) in a coastal P. thunbergii forest. After thinning, the regenerated seedlings, soil water content, light condition (canopy openness or canopy density), wind regime, and litter depth and quantity were investigated for four growing seasons. The relationships between the regenerated seedlings and light condition, litter, wind profile and soil water content were examined. The results showed that thinning could improve the light condition on the forest floor, increase the exchange of airflow (wind speed) in the coastal forest stand, and ameliorate the water content of the forest soil. These factors accelerated the decomposition of litters, and provided necessary conditions for natural regeneration. The results of regeneration observation indicated that the most intensively thinned treatment (50% thinned with density of about 1500 stems.hm-2) could provide a better condition for regeneration during the four growing seasons. The density and growth of seedling (greater than 1 year) increased significantly with increasing thinning intensities, and the establishment of seedlings was obviously succeeded in the most intensively thinned treatment, but failed in less thinned treatments and understory. The thinned intensity of 50% did not induce wind damage to the coastal forest in the four years after thinning, and did not cause the loss of shelter functions of the coastal forest such as sand blocking, wind breaking and salt preventing etc.. On the contrary, it could provide the suitable conditions for natural regeneration of the pine coastal forest, or for the immigration of other species. Therefore, thinning as the silviculturally created openness is very important for the establishment of seedlings in the coastal forests, which provides a mechanism for the coastal forest from even aged stands dominated by P. thunbergii to stands containing multiple size classes and canopy layers.
Analyses on the effects of the different scales of human disturbance on restoration of Castanopsis carelesii forest in Wupin, Fujian indicated that with increasing degrees of the scales of human disturbance (A class, regeneration by selected cutting; B class, natural regeneration; C class, natural regeneration promoted by artificial tending; D class, Chinese fir forest), the important value of Castanopsis carlesii and the similar index between the communities decreased, and the assembling and abundance degrees of species increased under disturbance of B or C class, and decreased under D class. It could be concluded that the disturbance of A class was light, that of B class was medium and could be restored rapidly, disturbance of C class was also medium but would be restored in a longer period, and that of D class was difficult to be restored due to the intense disturbance.
With the development of world economy and the increment of urban population, the urban environment problem hinders the urban sustainable development. Now, more and more people realized the importance of urban forests in improving the quality of urban ecology. Therefore, a new subject, urban forest ecology, and correlative new concept frame in the field formed. The theoretic foundation of urban forest ecology derived from the mutual combination of theory relating to forest ecology, landscape ecology, landscape architecture ecology and anthrop-ecology. People survey the development of city from the view of ecosystem, and regard the environment, a colony of human, animals and plants, as main factors of the system. The paper introduces systematically the urban forest ecology as follows: 1) the basic concept of urban forest ecology; 2) the meaning of urban forest ecology; 3) the basic principle and theoretic base of urban forest ecology; 4) the research method of urban forest ecology; 5) the developmental expectation of urban forest ecology.
The stand biomass and primary net productivity of artificial tropical rainforest in Xishuangbanna were estimated, based on sample tree method and harvesting method. The results showed that the standing biomass was 390.4 t.hm-2, of which, 362.5 t.hm-2(92.8%) were contributed by tree layers. The biomass of shrub and inter-layer plants (including epiphytes) was 19.3 t.hm-2(4.9%) and 3.6 t.hm-2(0.9%), respectively, and that of herbaceous layers was 5.0 t.hm-2. The primary net productivity of the stand was 2227.3 g.m-2.yr-1, of which, 1553.5 g.m-2.yr-1(69.7%) were contributed by tree layers. In the allocation of primary net productivity in different parts of trees stems showed the highest net productivity, accounted for 42.0%. Leaves and branches were accounted for 30.2% and 13.5%, respectively. The leaf area index (LAI) was 7.061. The optimum regression models of different dominant plants and organs of the sample trees of tree layer in the artificial tropical forest were built.
Soil quality is one of the most important environmental factors in sustaining the global biosphere and developing sustainable agricultural practices. A study was initiated in Wolong Nature Reserve, Sichuan Province, China to elucidate the soil quality changes of natural secondary succession, forest planting and agricultural practices after deforestation in the humid mountainous region. The soil qualities of six land use types (natural forestland, grassland, shrub land, secondary forestland, cultivated land and reforested land) were compared using two quantitative methods: the integrated soil quality index (QI) and soil deterioration index (DI). The QI values of natural forestland, grassland, shrub land, secondary forestland, cultivated land, reforested land were 0.8039, 0.3277, 0.9127, 0.6881, 0.0285 and 0.3183, respectively. The DI values were 0%, -14%, 12%, 1%, -26% and -18% respectively. Both indexes suggested that shrub land can restore soil properties. To compare the two methods more directly, a deduced index QI' based on QI value was developed. The results showed that DI and QI' had a very high linear correlation coefficient (r = 0.9775) despite the values were different. Both methods were efficient in evaluating the soil quality levels and DI was a more simple way in soil quality assessment, while QI could show more ecological meanings.
The piñon (Pinus edulis Engelm.)-juniper [Juniperus monosperma (Engelm.) Sarg.] woodlands of Bandelier National Monument are experiencing accelerated erosion. Earlier studies suggest that causes of these rapidly eroding woodlands are related to an unprecedented rapid transition of ponderosa pine (Pinus ponderosa C. Lawson) savanna to piñon-juniper woodlands as a result of cumulative historical effects of overgrazing, fire suppression, and severe drought. To study the effectiveness of slash treatment in reducing accelerated erosion, we used sediment check dams to quantify sediment yield from twelve paired microwatersheds (300-1100 m2) within an existing paired water-shed study. Six of the twelve microwatersheds were located in a 41-ha (treatment) watershed with scattered slash treatment, whereas six microwatersheds were located in an adjacent 35-ha untreated (control) watershed. The primary purpose of our research was to quantify the rates of sediment yield between the treated and control microwatersheds. Sediment yield was measured from 15 individual storms during the months of June-September (2000 and 2001). In response to slash treatment, mean seasonal sediment yield for 2000 equaled 2.99 Mg/ha in the control vs. 0.03 Mg/ha in the treatment and 2.07 Mg/ha in the control vs. 0.07 Mg/ha in the treatment in 2001. The practice of slash treatment demonstrates efficacy in reducing erosion in degraded piñon-juniper woodlands by encouraging herbaceous recovery. Our data show that slash treatment increases total ground cover (slash and herbaceous growth) beyond a potential erosion threshold. Restored piñon-juniper woodlands, as the result of slash treatment, provide a forest structure similar to pre-grazing and pre-fire suppression conditions and decrease catastrophic fire hazard.
The removal of litterfall in the Eucalyptus plantations in South China affected the plant biodiversity in these ecosystems was found based on the field observation and lab analysis. The protection times of species diversity of three Eucalyptus communities were different (Community I with no protection, Community II with 7-year-protection, Community III with 35-year-protection). The total numbers of species in these communities (from Community I to II to III) are 1, 6, and 17 respectively. The results showed that the protection of litterfall from being taken out of the ecosystem is important and can increase plant species diversity. This study combined biomass data, the chemical and physical properties of the soil, and the diversity of microbes in the communities. It is concluded that the mechanism of the effects of litter removal on biodiversity includes three factors: removing the suitable habitat of microbe and animal, decreasing the soil nutrient, and changing the special habitat for the germination and growth of invading plants. These results should have important implications for managing these Eucalyptus forest ecosystems in South China.
The traditional agricultural landscape of Japan, known as satoyama, consists of a mixture of forests, wet rice paddy fields, grasslands, and villages. This landscape supports a great diversity of plant and animal species, many of which are significant to the Japanese culture. The satoyama landscape is currently being rapidly converted to residential and industrial uses in Japan's expanding metropolitan areas, with the local loss of many species. Only 7% of the land in the Yokohama area remains as satoyama. City residents and older farmers have become key participants in programs to protect examples of satoyama. Many urban residents value the experience of participating in agricultural and conservation activities once they are made aware of the threat faced by the satoyama landscape. In one particularly successful program, conservation efforts and fund-raising are linked to "Totoro", an imaginary forest animal featured in a popular animated film.
By means of the photoplethysmographic method including the cold test, skin blood flow was recorded in the fingers of 42 chain-saw operators and 36 control subjects. The essential difference between the groups pertained to the height of the pulse wave amplitude after the cold test and to the fall in amplitude expressed as a percentage of its initial value. A limit of a 90% fall in amplitude after the cold test is proposed as a criterion for differentiating a normal from a pathological vasospastic reaction. A fall in amplitude is correlated with the intensity of subjective disorders, i.e. the attack of vibration-induced white fingers. The obstructive form and loss of amplitude of the pulse wave form are accepted as pathological.
In this study, growth potential of Crimean juniper (Juniperus excelsa Bieb.) seedlings for the first growing season under Tekir Forest Nursery conditions in Kahramanmaras was evaluated. The height growth of Crimean juniper seedlings was relatively close to that of Lebanon cedar (Cedrus libani A. Rich.) seedlings produced in the same nursery, but their root collar diameters were fairly lower than that of Lebanon cedar seedlings. According to coniferous seedling standards of Turkish Standards Institute, the height growth of Crimean juniper seedlings was fairly good, but their root collar diameters were slightly small. In this respect, that 2+0 or 1+1 Crimean juniper seedlings are used in reforestation activities in the region would be more useful than 1+0 seedlings.
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The impacts of economic forest on global environmental change (GEC) are one of the hot issues in environmental study. Based on the 3-year observation data and 40-year climate data, GEC and analysis of the hydrological dynamic characteristics of rubber plantations and estimate of the water balance in the rubber plantations in Hainan Island were made. The results showed that the rainfall intercepted by the canopy of the plantations accounted for 11.45% of the annual rainfall, the total runoff for 23.71%, the total evaporation and transpiration for 63.24%, the soil moisture storage for 1.6%. Analysis of the 40-year rainfall data in the 19 counties of Hainan Island during 1951-1990 showed that the large-scale substitution of the natural vegetation with the rubber plantations had no significant effect on the local rainfall in Hainan Island. The main reasons are (1) 80% of the rainfall in Hainan is brought by typhoons; (2) the proportion of 11.6% rubber plantations in total forest coverage in Hainan is not enough to influence the local rainfall in Hainan Island; and (3) although the rubber plantation is artificial vegetation, it has the similar function to the tropical rain forest. Analysis of the total water resource and total GDP of Hainan in 1997 showed that the economic benefit resulted from the water resource was 1.0 RMB Yuan/m3. The value of hydrological of the rubber plantation in Hainan was 113.9 million RMB Yuan/3 when compared with the tropical rain forest. The paper reaches conclusion that the hydrological eco-service function of rubber plantation has been enhanced after transformed from natural vegetation, which includes the natural service and powerful social service.
The study evaluated the possibility of using mangrove plantation to treat municipal wastewater. Two types of pilot scale (100 x 150 m2) free water surface constructed wetland were set up. One system was a natural Avicennia marina dominated forest system. The other system was a newly planted system in which seedlings of Rhizophora spp., A. marina, Bruguiera cylindrica and Ceriops tagal were planted in 4 strips. Municipal wastewater was retained within the systems for 7 and 3 days, respectively. The results indicated that the average removal percentage of TSS, BOD, NO3-N, NH4-N, TN , PO4-P and TP in the newly planted system were 27.6-77.1, 43.9-53.9, 37.6-47.5, 81.1-85.9, 44.8-54.4, 24.7-76.8 and 22.6-65.3 respectively. Whereas the removal percentage of those parameters in the natural forest system were 17.1-65.9, 49.5-51.1, 44.0-60.9, 51.1-83.5, 43.4-50.4, 28.7-58.9 and 28.3-48.0, respectively. Generally, the removal percentages within the newly planted system and the natural forest system were not significantly different. However, when the removal percentages were compared with detention time, TSS, PO4-P and TP percentages removed were significantly higher in the 7-day detention time treatment. Even though the removal percentages were highly varied and temporally dependent, the overall results showed that mangrove plantation could be used as constructed wetland for municipal wastewater treatment in a similar way to the natural mangrove system.
The Ganga is the most important perennial river originating from Gangotri in the snow-bound Himalayas about 3,900 m above mean sea level. Gorging a distance of about 220 km in the Himalayas, it enters the plain at Hardwar and after meandering and braiding over a distance of about 2,525 km through the Indo-Gangetic plains, ultimately joins the Bay of Bengal. The course of this river has been changed due to: (i) subsurface geotectonic movement leading to change in slope of the deltaic plain and subsidence of the Bengal basin; (ii) changing pattern of water discharge with time; (iii) variations in sediment load. The environment of Ganga basin is also deteriorating with time due to severe natural episodes of periodic floods and storms as well as anthropogenic factors such as population growth, deforestation, agricultural activities, urbanisation, fertiliser and fossil fuel consumption and construction activities such as dams and bridges. All these have inconceivable adverse impacts on the health and natural regeneration capacity of the river basin. The presence of micropollutants in water and sediments of this river turns the system into being unsustainable to the biota. The present study synthesises the available information on the changes of its geological, geomorphological and ecological aspects and suggests some remedial measures to be adopted now and in future.