Effects Of Anthropogenic Activities Research Articles

Soil Characteristics under Three Vegetation Types Associated with Shifting Cultivation in a Mixed Dipterocarp Forest in Sarawak, Malaysia

In order to provide appropriate soil information for the rehabilitation of tropical rainforest ecosystems, we examined the soil morphological, physico-chemical, mineralogical properties and charge characteristics in a degraded mixed dipterocarp forest with three type of vegetation, namely grassland, secondary forest, and remnant forest in Japan Sarawak Friendship Forest, Sarawak, Malaysia. We compared the soil properties at six representative locations differing in topography and vegetation types, with special reference to the effect of anthropogenic activities on the catenary sequence. All the soils were acidic or weakly acidic. Contents of clay, exchangeable Al, Alo, Ald and Fed and the values of the cation exchange capacity and Al saturation increased with depth. The clay mineral composition was dominated by kaolin minerals. The value of point of zero salt effect ranged from 3.0 to 4.0, indicating that the soil was not yet strongly weathered. A catenary sequence of the soils was observed; softer in soil hardness, higher contents of total exchangeable bases in the lower slope plots than in the upper slope plots and higher values of Feo/Fed in the surface horizon in the lower slope plots than in the upper slope plots. However, the effect of anthropogenic activities was observed; higher contents of total exchangeable bases in the grassland than in the other vegetation types. Based on the stable condition on weathering and erosion, the upper slope plot of the remnant forest exhibited a thicker O horizon, lower Feo/Fed values and a relatively high amount of chlorite. Soil variability should be taken into account for appropriate management of rehabilitation in tropical rainforests.

Meiobenthos in intermittently open/closed coastal lakes in New South Wales: spatial and temporal patterns in densities of major taxa

Intermittently open/closed coastal lakes and lagoons (ICOLLs) are common in Australia. Isolation from the sea makes them susceptible to nutrient enrichment and pollution and many are considered degraded. Understanding of their ecology and the effects of anthropogenic activity is limited. Many lakes are kept open artificially to improve water quality and mitigate the effects of floods. The present study examined the relationship between multivariate and univariate patterns in higher taxa of meiobenthos and compared their densities and distributions in naturally open and closed lakes with those in managed lakes. The degree of correspondence between multivariate and univariate patterns was taxon and locality dependent. Differences in densities between types of lakes was not related to physical factors. Within lakes, meiobenthos generally correlated negatively with salinity and organic content, but positively with silt. Densities reflected the degree of isolation from the sea, but the influence of this factor varied among lakes within categories and between taxa. Most taxa were less abundant in isolated localities, such as the inner reaches of lakes and in closed lakes. Meiobenthos were more spatially variable in closed and in managed lakes. The influence of frequency and duration of closure on the ecology of coastal lakes is discussed.

Assessment of metal and nutrient concentrations in river water and sediment collected from the cities in the Pearl River Delta, South China

The effects of anthropogenic activities, industrialization and urbanization on the accumulation of heavy metals and nutrients in sediments and water of rivers in the Pearl River Delta region were examined. Most sediments were seriously contaminated with Cd, Pb, and Zn in accordance with the classification by Hong Kong Environmental Protection Department. Total phosphorus (P) and nitrogen (N) concentrations in sediments ranged from 0.02% to 0.12% and 0.06% to 0.64%, respectively. High carbon (C), N, P and sulphur (S) levels at Yuen Long Creek were related to the discharge of industrial effluents along the river. The enrichment of P and ammoniacal-nitrogen (NH 4 +-N) in water were obvious. For most sites, the P concentration exceeded 0.1 mg/l, which is the recommended concentration in flowing water to encourage excessive growth of aquatic plants. Nine out of the 16 sites studied had NH 4 +-N concentration over 2 mg/l. The rivers in the south of Deep Bay (Hong Kong) had high nutrient exports compared with the rivers in the east region and western oceanic water. The concentrations of nitrate-nitrogen NO 3 −-N in surface water were under the maximum contaminant level in public drinking water supplies (10 mg/l) except for one site. Although the concentrations of heavy metals in overlying water were low, their accumulations were significant. High contents of nickel (Ni) and zinc (Zn) in water were found at certain locations, suggesting the occurrence of some local contamination. These preliminary results indicated that river and sediment transported pollutants is likely one of the factors for the water quality degradation of Deep Bay water.

Assessing Marine Ecosystem Health: The long-term effects of fishing on functional biodiversity in North Sea benthos

Assessments based on the taxonomic composition and relative abundance of taxa provide valuable information about the effects of anthropogenic activities on benthic systems. However, international agreements also require active conservation of ecosystem functioning as well as biological assemblages. We must therefore learn more about how ecosystems function and why changes occur within them in order to fully understand the implications of human activities. Biological traits analysis allows systems to be described in terms of the characteristics of member taxa, describing functional diversity whilst retaining information on taxa distributions. This study used biological traits analysis to investigate the long-term effects of fishing on benthic infaunal communities. Infaunal abundance was recorded over three decades at two stations, one within and one outside a fishing ground in the central western North Sea. Each taxon present was categorised for the degree to which it exhibited certain biological traits. The distribution of these traits within a sample produced a picture of functional diversity. Multivariate analyses were used to compare trait composition at the stations over time, thus depicting how community functioning responded to physical disturbance. The assemblages at the two stations were functionally distinct at the onset of the study; with differences in size, feeding type and reproductive method. The functional structure changed over time at the station within the fishing ground as the level of exploitation varied. Large animals, predators, scavengers and those eating invertebrates or carrion dominated years of light effort in the fishing ground but were less represented when effort increased. No such changes occurred at the station outside the fishing ground. Fishing seems to have some effect on benthic functional biodiversity and this effect is most obvious when moving from low to moderate levels. The differences between stations at the start of the timeseries may reflect variations in the physical environment or may result from effects of fishing that predate the timeseries.

RAINFALL, STEMFLOW, AND THROUGHFALL CHEMISTRY AT URBAN- AND MOUNTAIN-FACING SITES AT MT. GOKURAKUJI, HIROSHIMA, WESTERN JAPAN

Rainfall, stemflow, and throughfall were collected from 1996 to 1999 at two types of forest sites: (1) forests near the traffic roads and urban areas and (2) forests away from the urban areas at Mt. Gokurakuji, Hiroshima, western Japan in order to estimatethe effects of anthropogenic activities on atmospheric deposition. Rainfall deposition for major ions showed small differences between the sites. The NO3 - and SO4 2-concentrations in stemflow were higher at the urban-facing slope than at the mountain-facing slope. Throughfall deposition of NO3 - and SO4 2- was also higher at urban-facing slopes. Net throughfall (NTF) deposition (throughfall minus rainfall) of NO3 - and SO4 2- accounted for 77 and50% of the total throughfall deposition on urban-facing slopes, respectively, while it accounted for 44 and 23% on themountain-facing slopes, respectively. These results indicated a higher contribution from dry deposition on urban-facing slopes compared to mountain-facing slopes. Atmospheric N (NO3 - +NH4 +) deposition from throughfall was estimated to be around 17–26 kg N ha-1 yr-1 on urban-facing slopes, which was greater than the threshold of N deposition that could cause nitrogen leaching in Europe and the United States. The highload of atmospheric N deposition may be one of the factors bringing about the decline of pine forests on urban-facing slopesof Mt. Gokurakuji.

Parametrization and evaluation of marine environmental impacts produced by deep-sea manganese nodule mining

Abstract The evaluation of marine environmental impacts resulting from the exploitation of marine resources requires the numerical description, parametrization, and modelling of such processes in order to be able to transfer, compare, and forecast the effects of anthropogenic activities in the deep sea. One of the controversial effects is the formation and behaviour of sediment clouds as a consequence of anthropogenic activities on the seafloor. Since there is a need for reliable data, two subprojects of the “Interdisciplinary Deep-sea Environmental Protection Group (TUSCH)”-project “Impacts from Technical Activities on the Deep-Sea Ecosystem of the South East Pacific Offshore Peru (ATESEPP)” were devoted to the assembly of such data. Based on the German technical approach for deep-sea mining, the possible environmental impacts by a miner were estimated, the impacts on the seafloor were simulated and investigated by tests with large volume undisturbed sediment samples on board the research vessel and in the laboratory, and the results were evaluated and extrapolated. This report gives a comprehensive presentation of the physical problems, the technical approach, and the results of these investigations.

Genetic diversity and heavy metal tolerance in populations of Silene paradoxa L. (Caryophyllaceae): a random amplified polymorphic DNA analysis.

Metal-contaminated sites can occur naturally in serpentine outcrops or as consequence of anthropogenic activities, such as mining deposits, aerial fallout from smelters and industrial processes. Serpentine outcrops are characterized by high levels of nickel, cobalt and chromium and present a typical vegetation which includes endemisms and plants which also live in uncontaminated soils. These latter metal-tolerant populations provide the opportunity to investigate the first steps in the differentiation of plant populations under severe selection pressure and to select plants to be used in the phytoremediation of industrially contaminated soils. In this report eight populations of Silene paradoxa L. (Caryophyllaceae) growing in copper mine deposits, in serpentine outcrops or in noncontaminated soil in central Italy, were analysed using random amplified polymorphic DNA (RAPD) markers to investigate the pattern of genetic variation. The genetic diversity observed in populations at copper mine deposits was found to be at least as high as that of the neighbouring serpentine populations. Analysis of molecular variance (AMOVA) of the RAPD markers gave high statistical significance to the groupings of populations according: (i) with their geographical location; and (ii) with the metals present in the soil of origin (copper vs. nickel), indicating that RAPD markers detected a polymorphism related to the soil contamination by copper. Finally, two RAPD bands exclusive to copper-tolerant populations were identified.

Effects of burning and grazing on carbon sequestration in a Pennine blanket bog, UK

Terrestrial ecosystems contain large amounts of carbon (C) and have the potential to significantly increase atmospheric carbon dioxide (CO2) concentrations. Peatlands are particularly important for C storage, although little is known about the effects of anthropogenic activities on C balance in these ecosystems. Sheep-grazing and rotational burning are widely practised on blanket peat moorlands in the United Kingdom. The effects of these activities on C sequestration in peat has been investigated with a long-term randomized block experiment with treatments: (a) grazed + unburnt; (b) grazed + burnt every ten years; (c) ungrazed + unburnt. C accumulation under these treatments was compared by identifying a chronologically synchronous horizon within the peat common to all treatment plots. This fixed point was defined by the ‘take-off’ in concentration of spheroidal carbonaceous particles and was supported by the record of charcoal fragments. There was no significant difference in recent C accumulation rates between lightly grazed and ungrazed plots. In contrast, after 30 years there was significantly less C stored in the blanket peat in plots which had been burned every ten years. The results indicate that light sheep-grazing at this site did not affect rates of C accumulation in blanket peat, but decadal burning of moorland reduced C sequestration.

Functional substrate biodiversity of cultivated and uncultivated A horizons of vertisols in NW New South Wales

Concern over the effects of anthropogenic activities on soil ‘quality’ has fuelled efforts to identify and measure those factors that affect soil quality. Soil microbial diversity is one of many possible factors. Our objective was to compare the functional diversity of microbial communities in the A horizons of cultivated and uncultivated vertisols in NW New South Wales. Samples from two cultivated and two uncultivated sites were tested using the community level physiological profiles (CLPP) method. Substrate richness, the rate of substrate use and the diversity of substrate use, as measured by the Shannon index, were significantly larger in the uncultivated sites than in the cultivated sites. The CLPP also indicated a higher rate of substrate use in the uncultivated sites, although this may have been due to greater initial inoculum densities. When diversity values for each site were compared with several soil physical and chemical properties, a relationship between organic carbon and functional diversity was apparent. The fit to a broken-stick model showed that diversity increased up to 1.76% organic carbon and remained constant above that value. The implications of these results for soil quality will depend upon future investigations on the significance of soil microbial diversity as a component of soil quality.

Effect of Components of 'Acid Rain' on the Contribution of Soil Microarthropods to Ecosystem Function

This study evaluates the functional consequences of stressing microarthropod assemblages (Acari and Collembola) in a Norway spruce, Picea abies (L.) Karsten, forest soil with the chronic proton and low-level nutrient input associated with 'acid rain'. Assemblages of microarthropods from the organic layer of the forest floor plots, sprayed over a 4-year period with potential components of polluted rain, namely nitric acid, sulphuric acid, ammonium sulphate, ammonium nitrate and ammonium chloride, were introduced into laboratory microcosms which contained unpolluted litter. Assemblages from plots treated with urea and distilled water were also included to extend the range of contrasts. Leaching of ammonium-N, nitrate-N, sulphate-S, chloride, calcium, magnesium, potassium and sodium from the microcosms was measured over a 10-week period. Leachate pH and the evolution of CO2 from the microcosms were also measured. Differences in the mean biomass of microarthropods were detected at the end of the experimental period. The biomass of assemblages from ammonium nitrate, urea and sulphuric acid plots were greater than that from nitric acid, water, ammonium sulphate and ammonium chloride plots. The abundance of five species, Isotoma notabilis Schaffer, Friesea mirabilis Tullb., Oppiella nova (Oudemans), Macrocheles sp. and Cilliba cassidea (Herm.) differed between the assemblages. Differences existed between the microcosms in the leaching of all anions and cations measured and the amounts of CO 2 evolved on at least one occasion. Initially, the leaching of N0 3 -N was low, but increased over the 10 weeks whereas NH 4 -N was relatively high initially, but decreased by the end of the experiment. The leaching of calcium and magnesium was highly positively correlated with that of nitrate. Leaching of potassium correlated positively with that of NH 4 -N. A positive, but weak relationship existed between respiration, measured by CO 2 evolution, and NO 3 -N leaching, and a negative relationship existed with NH 4 -N leaching. Many, though not all, of the differences between elemental losses from microcosms were elevated or diminished losses from microcosms containing animals originating in ammonium chloride (AC) or ammonium sulphate (AS) field plots. No differences were detected when the impact of assemblages derived from the two acid-treated plots were contrasted. When losses from microcosms containing animals from all sprayed plots were compared with losses from microcosms with undisturbed assemblages (i.e. treated with distilled water) significant differences were found for all parameters except for the leaching of sodium. The results indicate that perturbation of the microarthropod assemblage, as a consequence of anthropogenic activity, may have impacts upon decomposition and the local availability of labile nutrients.

Estimating ecotoxicological risk and impact using indigenous aquatic microbial communities

Emphasis has increased on accuracy in predicting the effect that anthropogenic stress has on natural ecosystems. Although toxicity tests low in environmental realism, such as standardized single species procedures, have been useful in providing a certain degree of protection to human health and the environment, the accuracy of such tests for predicting the effects of anthropogenic activities on complex ecosystems is questionable. The use of indigenous communities of microorganisms to assess the hazard of toxicants in aquatic ecosystems has many advantages. Theoretical and practical aspects of microbial community tests are discussed, particularly in related to widely cited problems in the use of multispecies test systems for predicting hazard. Further standardization of testing protocols using microbial colonization dynamics is advocated on the basis of previous studies, which have shown these parameters to be useful in assessing risk and impact of hazardous substances in aquatic ecosystems.

Le temp et l'éspace dans les recherches écologiques sur la dynamique de la végétation

Abstract Time and space in ecological studies on vegetation dynamics. Considerations on the significance of time and space in ecological studies on vegetation dynamics may concern three groups of problems philosophical-methodological, organisational-methodological and cognitive. (I) The first group comprises above all: (1) the limits of understanding and acceptation by ecologists the proper for philosophy and contemporary physics concept of integrating time-space and the possibillity of inclusion into our own notions and those borrowed from ecology, without losing sight of the functional approach to the studied phenomena, which is specific for this discipline; (2) How to recognize the true significance of time for the behaviour of the given ecosystem, biocenosis, phytocenosis, population and the moment of their arising and at any moment of their duration? Can the lifetime of a forest, a tree, a herb and its seed be counted in the same way? Is the search for special ecological time measures indispensable, beside the external, astronomical time measures, for expressing the immanent properties of ecological relations and intervals? (II) The significance of the time and space factor in the process of becoming acquinted with ecological phenomena arabicWhat phenomena or process can be observed in various time intervals?arabicHow much time and how large space are necessary for investigating any major ecological process, for instance primary and secondary succession, regression, formation of some relations and interactions?arabicHow should phenomena occurring synchronously be subjected to analysis of causes and consequences, when their nature is obscured by numerous stochastic processes?arabicWhat possibility is there of reconciling methodical progress with the condition off preservation of a uniform approach to the observed phenomena over a very long time, for instance 10-15 years?arabicWhat possibility and limits are there of generalisation in space-time and synthesis of results of ecological dynamic research, usually based on sampling? It is known that sample collection is not always representative and sufficiently numerous since it is not possible to fulfil completely in practice the postulates of statistics and the theory of sampling. There is another question in this group which dominates all other, namely;arabicWhat is the possibility of avoiding «contamination» of the results of ecological studies, especially of long standing by effects of anthropogenic activity?

The Oxygen Monitoring of the Danube River on the Section Oltenita-Black Sea

Danube river basin overlaps great depressions of C entral and SE Europe is the second largest river in Europe and 24 th in the world.The Romanian section represents 29% of the surface area of the whole basin, with 37.7% of the river flowing through its territory. Organic pollution has been increasing in parts of the Danube Basin up till the end of the last century, as industrial production and hous ehold consumption have resulted in increasing loads of wastewater rich in organic matt er.Together with other countries, Romania is part of the transfrrontalier program. The TransN ational Monitoring Network, in short “TNMN” was established to support the implementation of the Danube River Protection Convention in the field of monitoring and assessmen t. In order to monitorize the section Olteni Ńa-Black Sea, in 2008 were taken in study 4 sites, namely: Chiciu, Braila, Tulcea and Sulina. F or this study we have monitored the oxygen represented by: OD, BOD5, CCO-Cr, CCO-Mn, indicators that determine pollution with organic compounds. The methods we used within the European norms and the monitored parameters were analyzed with specialized equipment, like the device for determining the BOD model OxiTop IS 6. In the study the BOD values are higher in the months of spring and summer and indicate the quantity of oxygen required for oxidation the organic materials. Differences between BOD and CCO CCO-Mn-Cr gave us clues on industrial water discharged into emissary. In this study, significan t differences are observed, even two times higher CCO-Cr and CCO-Mn compared to BOD, the water is polluted with organic material from waste water discharged by various industries i n the Danube River tributaries. Dissolved oxygen was determined using Oxigenometrului inoLab730 P, and the values varys depending on atmospheric pressure, water temperature, content of mineral salts, micro-organisms in water. In this case there are no significant differences compared to the maximum allowed. It is recommended the monitoring of the Danube River water quality; the public awareness about the negative effects of anthropogen ic activities on water quality.