Assessing implications of land use and land cover changes in forest ecosystems of NE Turkey

Monitoring land use and land cover change (LUCC) and understanding forest cover dynamics is extremely important in sustainable development and management of forest ecosystems. This study analyzed the spatial and temporal pattern of LUCC in the Yaln?zçam and U?urlu forest planning units which are located in the northeast corner of Turkey. The investigation also evaluates the temporal changes of the spatial structure of forest conditions through the spatial analysis of forest-cover type maps from 1972 and 2005 using geographical information systems and FRAGSTATS^TM. As an overall change between 1972 and 2005, there was a net increase of 1,823 ha in forested areas, and cumulative forest improvement accounted for 2.06 %. In terms of spatial configuration, the landscape structure in the study area changed substantially over the 33-year study period, resulting in fragmentation of the landscape as indicated by large patch numbers and smaller mean patch sizes, owing to heavy grazing, illegal cutting, and uncontrolled stand treatments.     

Persistence of metsulfuron-methyl in wheat crop and soil

Possible bioaccumulation of pesticides in crop produce may cause ailing effect on animal and human. Thus there is a need to evaluate these chemicals in the soil and crop produce at harvest. Metsulfuron-methyl is a post-emergence herbicide. It is highly active to control broad-leaf weeds in cererals, pasture and plantation crops. Metsulfuron-methyl was applied at 3, 4, 5, and 8 g a.i. ha(-1) rates, after 30 days of sowing in wheat as post-emergence herbicide. Soil samples treated with metsulfuron-methyl were collected after 30 and 60 days along with control and at harvest after herbicide application and analyzed for residues by High Performance Liquid Chromatography (HPLC) using photo diode array detector at 220 nm. Wheat grains and straw samples were sampled at harvest. At harvest the residue level of metsulfuron-methyl in soil was found below the detection limit at 3-5 g a.i. ha(-1) application rates and 0.002 microg g(-1) at 8 g a.i. ha(-1), respectively. No residues of metsulfuron-methyl were detected in wheat grains at 3-4 g a.i. ha(-1) rates. However 0.002 microg g(-1) residues were detected in wheat straw at 5 and 8 g a.i. ha(-1) application rates. It can be concluded that metsulfuron-methyl application at 3-4 g a.i. ha(-1) can be safely applied to the wheat crop as post-emergence herbicide.     

Persistence and bioaccumulation of oxyfluorfen residues in onion

A field study was conducted to determine persistence and bioaccumulation of oxyflorfen residues in onion crop at two growth stages. Oxyfluorfen (23.5% EC) was sprayed at 250 and 500 g ai/ha on the crop (variety, N53). Mature onion and soil samples were collected at harvest. Green onion were collected at 55 days from each treated and control plot and analyzed for oxyfluorfen residues by a validated high-performance liquid chromatography method with an accepted recovery of 78–92% at the minimum detectable concentration of 0.003 μg g^???1. Analysis showed 0.015 and 0.005 μg g^???1 residues of oxyfluorfen at 250 g a.i. ha^???1 rate in green and mature onion samples, respectively; however, at 500 g a.i.ha^???1 rates, 0.025 and 0.011 μg g^???1 of oxyfluorfen residues were detected in green and mature onion samples, respectively. Soil samples collected at harvest showed 0.003 and 0.003 μg g^???1 of oxyfluorfen residues at the doses 250 and 500 g a.i. ha^???1, respectively. From the study, a pre-harvest interval of 118 days for onion crop after the herbicide application is suggested.     

Persistence and Distribution of Endosulfan under Field Condition

Rapid increase in industrialization and agricultural activities to meet the population need has led to environmental pollution. The major revolution in agricultural production is mainly due to increased use of pesticides and fertilizers. Soil act as a major sink for majority of pesticides applied on agricultural crops. Among the organochlorines, endosulfan is the most commonly used pesticide, hence this study concentrates on the persistence and distribution behaviour of endosulfan under field conditions. The result showed that the alpha endosulfan concentrations were very minimum (0.98 mg/kg of soil) in all the four fields under study (Nazarath, Othikadu, Ekkadu and Ekkadukandigai of Thiruvallur district, Tamil Nadu). Where as beta endosulfan concentration at the time of application was 6.39 mg/kg and declined to 0.8 mg/kg on soil at 150th day. The endosulfan sulfate concentration was 11.8 mg/kg in soil at 15th day and then concentration declined to 2.2 mg/kg at 150th day. Field run-off samples showed maximum residue levels (0.024 mg/l) at the early irrigation period. While plant foliar parts showed maximum concentrations of α-endosulfan (43.4 mg/kg), β-endosulfan (40.6 mg/kg) and endosulfan sulfate (20.1 mg/kg). At harvest stage, rice grain and husk also had lower concentrations of endosulfan sulfate (2.2 and 0.09 mg/kg), respectively.     

Monitoring of the functioning of ecosystems

The theoretical basis, the content and the possible applications of the program Monitoring of ecosystems are considered. A functional definition of ecosystem is proposed, and some features of ecosystems are defined on this basis. The program Monitoring of ecosystems is visualized as a large-scale program of simple measurements of the rates of the main ecosystem processes. The expected results can be utilized in two ways: (1) a comparative knowledge of ecosystem functioning provides the fundamentals of geography of ecosystems, and (2) the constant, repeatable evaluation of a given ecosystem function provides a basis for its rational management.     

Persistence and risk assessment of spiromesifen on tomato in India: a multilocational study

Supervised field trials were conducted at four different agro-climatic locations of India to evaluate the dissipation pattern and risk assessment of spiromesifen on tomato. Spiromesifen 240 SC was sprayed on tomato at 150 and 300 g a.i.?ha^?1. Samples of tomato fruits were drawn at 0, 1, 3, 5, 7, 10 and 15 days after treatment and soil at 15 days after treatment. Quantification of residues was done on gas chromatograph–mass spectrophotometer in selective ion monitoring mode in the mass range of 271–274 (m/z). The limit of quantification of the method was found to be 0.05 mg kg^?1, while the limit of determination was 0.015 mg kg^?1. Residues were found below the LOQ of 0.05 mg kg^?1 in 10 days at both the doses of application at all the locations. Spiromesifen dissipated with a half-life of 0.93–1.38 days at the recommended rate of application and 1.04–1.34 days at the double the rate of application. Residues of spiromesifen in soil were detectable level (<0.05 mg kg^?1) after 15 days of treatment. A preharvest interval (PHI) of 1 day has been recommended on tomato on the basis of data generated under All India Network Project on Pesticide Residues. Spiromesifen 240 SC has been registered for its use on tomato by Central Insecticide Board and Registration Committee, Ministry of Agriculture, Government of India. The maximum residue limit (MRL) of spiromesifen on tomato has been fixed by Food Safety Standard Authority of India, Ministry of Health and Family Welfare, Government of India as 0.3 μg/g after its risk assessment.     

Where,why, and to what extent have rangelands in the Karoo,South Africa,desertified

We used simple questionnaire surveys to obtain rough categorical information on the status of semiarid and arid rangelands in the Karoo, South Africa. We sent questionnaires to extension officers of the Department of Agricultural Development, asking them to rank the condition of the rangeland in their extension districts (usually about 500 farms) on a three- or five-point scale. The questionnaire also sought information on the possible reasons for changes in the condition of the rangelands; vegetation types most at risk on mismanaged rangelands; and changes in the status of plants, birds, and mammals. Extension officers rated 35% of the semiarid rangelands in southwestern South Africa (the Karoo and southern Kalahari Desert) as being in poor condition. There was some congruency between the perceived condition of the agricultural extension district and the percentage that the stocking rate had decreased. Rangeland condition in more arid areas tends to be poor. Stocking rates have decreased disproportionately more in arid areas than in the more mesic areas of southwestern South Africa. Grasses were rated as the most threatened group of plants, and succulents the least threatened group. Overgrazing in the past was considered to be the most important cause of present-day rangeland condition, followed by present overstocking of rangelands. Antelope were considered more threatened by rangeland management than mammalian carnivores. Avian raptors and bustards, gamebirds, and tortoises were all perceived to be threatened by rangeland mismanagement.     

Persistence and Dissipation Kinetics of Spiromesifen in Chili and Cotton

In a field study carried out at three different locations, the dissipation of spiromesifen on cotton and chili was studied and its DT₅₀, and DT₉₉ were estimated at each location. Spiromesifen was sprayed on chili at 96 and 192 g a.i. ha⁻¹ and cotton at 120 and 240 g a.i. ha⁻¹. Samples of chili fruits were drawn at 0, 1, 3, 5, 7, 10, 15, 21, 30 days after treatment and that of cotton seed and lint at first picking and harvest. Soil samples were drawn 30 days after treatment from 0 to 15 and 15 to 30 cm layer. Quantification of residues was done on GC–MS in Selected Ion Monitoring (SIM) mode in mass range 271–274 m/z. The LOQ of this method was found 0.033 μg g⁻¹, LOD being 0.01 μg g⁻¹. The DT₅₀ of spiromesifen when applied at recommended doses in chili fruits was found to be 2.18–2.40 days. Ninety-nine percent degradation was found to occur within 14.5–16.3 days after application. Residues of spiromesifen were not detected in cotton seed and lint samples at the first picking. In soil, no residues of spiromesifen were detectable 15 days after treatment.     

Assessment of anthropogenic threats to Chilean Mediterranean freshwater ecosystems: Literature review and expert opinions

Anthropogenic threats and their impacts on aquatic ecosystems have traditionally been evaluated only through literature reviews. Within the last decade, however, expert opinions have become an increasingly popular alternative for gaining complementary information to literature reviews. This study employed a standardized method for collecting bibliographic data combined with synthesize expert opinions to establish a current knowledge baseline on threats to Mediterranean freshwater ecosystems in Chile.We revised 79 scientific articles that included a variety of taxonomic groups containing fish (n = 32); macroinvertebrates (n = 17); amphibians (n = 18); freshwater plants (n = 8); and two taxonomic groups simultaneously (n = 4). From this review, we identified 14 threats, with land-use change, species introductions, and industrial/domestic effluents as salient factors. These findings were in agreement with results from expert opinion surveys (n = 46 researchers). An analysis by taxonomic group indicated freshwater fishes as most threatened by hydropower plants. Aquatic plants were most threatened by mining. Amphibians were most threatened by changes in soil use whereas aquatic macroinvertebrates by industrial/domestic effluents. Remarkably, the magnitude of threats identified in the literature review was of similar order than those catalogued by experts. Moreover, the primary threats identified here align with those reported in other Mediterranean regions of the world. Our combined approach using literature review and expert opinion was useful in determining the consistency of the main threats to each taxonomic group. Our findings can be used as a baseline to further research and in prioritizing management strategies for threatened Mediterranean ecosystems worldwide.     

Use of large enclosures for perturbation experiments in lentic ecosystems: A review

Available literature on use of field enclosures in freshwater and marine systems is reviewed to assess how accurately enclosures mimic ecological conditions and process rates occurring in adjacent open habitat. Among- and within-replicate variability of ecological parameters in field enclosures is compared to those in laboratory microcosms and open field habitat respectively. Results concerning the potential ecological effects and fate of pollutants indicate that perturbation studies using field enclosures can provide defensible data at the population and community levels over time periods of several months and spatial scales of tens of meters. The degree of ecological realism that can be achieved, however, is variable. Chronic effects of some pollutants may be difficult to separate from nonspecific effects due to enclosure. Determination of cause/effect pathways for observed toxicant impacts generally will require supplemental laboratory studies.Work conducted under Electric Power Research Institute, Palo Alto, CA, contract RP 1822-6.     

The environmental behaviour of polychlorinated phenols and its relevance to cork forest ecosystems: a review

Pentachlorophenol (PCP) has been used as a herbicide, biocide and preservative worldwide since the 1930s and as a result, extensive and prolonged contamination exists. The environmental impact increases when its many degradation products are taken into consideration. A number of chloroanisols and their related chlorophenols have been found in cork slabs collected from Portuguese oak tree forests before stopper manufacturing, and contamination by PCP and polychlorinated anisole (PCA) has been detected in Canadian forests. It is suggested that the use of polychlorinated phenols, in particular PCP, is thought to be a cause of the cork taint problem in wine, a major socio-economic impact not only for industry but on sensitive and highly biodiverse ecosystems. It also highlights particular issues relating to the regional regulation of potentially toxic chemicals and global economics world wide. To fully understand the impact of contamination sources, the mechanisms responsible for the fate and transport of PCP and its degradation products and assessment of their environmental behaviour is required. This review looks at the current state of knowledge of soil sorption, fate and bioavailability and identifies the challenges of degradation product identification and the contradictory evidence from field and laboratory observations. The need for a systematic evaluation of PCP contamination in relation to cork forest ecosystems and transfer of PCP between trophic levels is emphasised by discrepancies in bioaccumulation and toxicity. This is essential to enable long term management of not only transboundary contaminants, but also the sustainable management of socially and economically important forest ecosystems.     

Cumulative effect assessment in Canada: a regional framework for aquatic ecosystems

Sustainable development of the aquatic environment depends upon routine and defensible cumulative effects assessment (CEA). CEA is the process of predicting the consequences of development relative to an assessment of existing environmental quality. Theoretically, it provides an on-going mechanism to evaluate if levels of development exceed the environment's assimilative capacity; i.e., its ability to sustain itself. In practice, the link between CEA and sustainable development has not been realized because CEA concepts and methods have developed along two dichotomous tracks. One track views CEA as an extension of the environmental assessment (EA) process for project developments. Under this track, stressor-based (S-B) methods have been developed where the emphasis is on local, project-related stressors, their link with aquatic indicators, and the potential for environmental effects through stressor-indicator interactions. S-B methods focus on the proposed development and prediction of project-related effects. They lack a mechanism to quantify existing aquatic quality especially at scales broader than an isolated development. This limitation results in the prediction of potential effects relative to a poorly defined baseline state. The other track views CEA as a broader, regional assessment tool where effects-based (E-B) methods specialize in quantification of existing aquatic effects over broad spatial scales. However, the predictive capabilities of E-B methods are limited because they are retrospective, i.e., the stressor causing the effect is identified after the effect has been measured. When used in isolation, S-B and E-B methods do not address CEA in the context necessary for sustainable development. However, if the strengths of these approaches were integrated into a holistic framework for CEA, an operational mechanism would exist to better monitor and assess sustainable development of our aquatic resources. This paper reviews the existing conceptual basis of CEA in Canada including existing methodologies, limitations and strengths. A conceptual framework for integrating project-based and regional-based CEA is presented.     

Tracing the fate of PCBs in forest ecosystems

Forests were shown to play an important role in influencing atmospheric concentrations and transport of persistent organic pollutants (POPs) in the environment. World forests cover more than 4 billion hectares and contain up to 80% of the above ground organic carbon. Given the lipophilic nature of POPs, this suggests that forests can influence the environmental fate of POPs at a global scale. POP accumulation in forest canopies still presents points of concern given the complexity of these ecosystems. In particular, the role of ecological parameters such as LAI (leaf area index) and SLA (specific leaf area) and their dynamics during the growing season was not sufficiently investigated yet. This paper reviews, compares and interprets a unique case study in which air and leaf concentrations and deposition fluxes for selected polychlorinated biphenyls (PCBs) were measured in three different forest types exposed to the same air masses. In order to trace the air-leaf-soil path of these compounds, a dynamic model of POP accumulation into forest canopy was applied. The dynamics of the canopy biomass strongly affected the trend of leaf concentration with time. Growth dilution effect can prevent the more chlorinated compounds from reaching the partitioning equilibrium before litter fall, while the more volatile compounds can approach equilibrium in the range of few weeks. An amount of up to 60 ng of PCBs per square metre of ground surface was predicted to be stored in each of the selected forests at fully developed canopy. Dry gaseous deposition fluxes to forest canopy were estimated to reach a maximum value of about 0.5-1.5 ng m(-2) d(-1) during the spring period.     

Persistence of dicofol residues in cotton lint seed, and soil

A supervised field trial was conducted at the CCS Haryana Agricultural University, Hisar to assess the residues of dicofol on cotton, during Kharif season, 2008. Dicofol (Kelthane 18.5EC) was applied at 500 g a.i./ha (T(1)) and 1,000 g a.i./ha T(2)) after 105 days of sowing of cotton crop (Varity Cotton/H-1226). Soil samples were collected on 0 (1 h after treatment), 3, 7, 10, 15, 30, and 60 days after spray and cotton samples were collected at harvest. Samples were processed and residues were quantified by GC-ECD system equipped with capillary column. Limit of detection and limit of quantification (LOQ) were 0.001 and 0.010 mg kg(?-1), respectively, for soil and LOQ for cotton lint and seed was 0.020 mg kg(?-1). Initial residues of 0.588 and 1.182 mg kg(?-1) in soil reached below detectable level (BDL) of 0.010 mg kg(?-1) in T(1) and to the level of BDL (0.010 mg kg(?-1)) in T(2) at harvest (60 days after treatment). In 60 days, residues dissipated almost completely (100 and >99%) in both the treatments. Half-life period was calculated as 8.57 days at single dose and 8.69 days at double dose in soil. Residues of dicofol were detected in cotton lint to the levels of 0.292 and 0.653 mg kg(?-1) and in seed 0.051 and 0.090 mg kg(?-1) in T(1) and T(2) doses, respectively at harvest. Residues in cotton seed were below MRL value of 0.01 mg kg(?-1) in both the doses.     

Persistence of fipronil and its metabolites in soil under field conditions

Fipronil belongs to phenylpyrazole class of chemical compounds. Degradation of fipronil in sandy loam soil was investigated under field conditions by applying fipronil (Regent 5 % SC) at 50 (T ₁) and 100 g a.i. ha^?1 (T ₂) in field. Samples were drawn periodically in triplicate on 0 (1 h after treatment), 1, 3, 7, 10, 15, 30, 60, and 90 days after treatment and analyzed on GC-ECD system equipped with capillary column. The residues of fipronil in both the doses dissipated in the range of 93.33–100 % in 90 days. Limit of detection (LOD) and limit of determination (LODe/LOQ) were 0.0003 and 0.001 mg kg^?1, respectively. Dissipation followed a biphasic first-order kinetics with half-life values of 10.81 and 9.97 days for fipronil alone and 8.14 and 13.05 days for fipronil along with metabolites in soil at (T ₁) and (T ₂) treatments, respectively.     

Biomonitoring of antimony in environmental matrices from terrestrial and limnic ecosystems

Elder and poplar leaves from various sampling sites were studied with respect to their antimony content. Moreover, a retrospective determination of Sb was performed in representative limnic and terrestrial samples of the Federal Environmental Specimen Bank of Germany which have been collected over 14 years. The analytical procedure is based on an open vessel acid digestion of freeze-dried biological samples and the subsequent quantification of Sb in the digests by flow injection hydride generation atomic absorption spectrometry. Strict quality control schemes were applied to the entire procedure to guarantee accurate and precise results. No long-term changes of the Sb concentrations were found in spruce shoots or poplar leaves from different sampling sites. However, spruce shoots from a semi-natural region showed concentrations of Sb (approximately 22 ng g-1; range: 17-29 ng g-1) that were approximately four times lower than in corresponding samples from an urban-industrialized area. The analysis of virgin and washed elder leaves revealed that approximately 20-30% of the Sb is present on the leaf surface. Sb levels in elder leaves ranged from 5.2 +/- 0.3 ng g-1 in samples from Argentina to 589 +/- 30 ng g-1 in leaves collected directly beside a motorway in Germany. Similarly, poplar leaves from Argentina and Chile showed about 4 ng Sb g-1, whereas 150 ng Sb g-1 was found in poplar leaves from Germany. The lowest concentrations of Sb were determined in digests of pigeon eggs (approximately 2 ng g-1), bream liver (approximately 4 ng g-1) and deer liver (approximately 6 ng g-1). A similar pattern of Sb concentrations in spruce shoots, leaves or liver samples from an industrialized area and an agrarian ecosystem in Germany was established. Concentrations of Sb in elder leaves were closely associated with car traffic, giving maximum concentrations of 589 ng g-1 directly beside a motorway, 207 ng g-1 50 m from the motorway and 153 ng g-1 in a close residential area.     

Persistence and behavior of pesticides in cotton production in Turkish soils

Turkey is the sixth largest producer of cotton in the world. Two of the most commonly applied pesticides used in cotton production are trifluralin and endosulfan. Although both are very effective at controlling pests, their persistence in the environment poses risks to human health and the environment. Four loam soils and one silty-loam soil were studied to evaluate the persistence of trifluralin and endosulfan in relation to soil characteristics. Degradation with trifluralin reached as high as 70% of the applied doses. Soils with the highest organic matter content had the lowest degradation rate, indicating a tighter sorption of trifluralin. Endosulfan degradation was a function of soil type and the specific isomer, with β-endosulfan depicting the highest degradation.     

Persistence behaviour of imidacloprid and its metabolites in soil under sugarcane

The persistence and metabolism of imidacloprid in soil under sugarcane were studied following application of imidacloprid at 20 and 80 g active ingredient (a.i.) ha^?1. Soil samples were collected at different time intervals (7, 15, 30, 45, 60 and 90 days after application), and the residues of imidacloprid and its metabolites (6-chloronicotinic acid, nitrosimine, imidacloprid-NTG, olefin, urea and 5-hydroxy) were quantified by high-performance liquid chromatography. In soil, the total imidacloprid residues were mainly constituted by the parent compound followed by 6-chloronicotinic acid, nitrosimine and imidacloprid-NTG metabolites. Maximum residues of imidacloprid and its metabolites were 4.29 and 7.81 mg kg^?1 in soil samples collected 7 days after the application of imidacloprid at 20 and 80 g a.i. ha^?1, respectively. At both doses, these residues declined to below the detectable limit in soil after 90 days of application. Olefin, urea and 5-hydroxy metabolites were not detected in soil. Dissipation of total imidacloprid residues did not follow the first-order kinetics with a coefficient of determination value of 0.883 and 0.838 for the recommended dose and four times the recommended dose, respectively. The half-life (T _1/2) value of total imidacloprid was observed to be 10.64 and 10.10 days for the recommended dose and four times the recommended dose, respectively.     

An inventory-based carbon budget for forest and woodland ecosystems of Turkey

Environmental monitoring of national-level comparisons of CO(2) emissions is needed to quantify sources and sinks of carbon (C) in national ecosystems. In this study, a national forest inventory database was used to estimate the past and current pools and fluxes of C in deciduous and coniferous forest and woodland ecosystems (20.7 x 10(6) ha) of Turkey. Growing C stock was 12.63 t C ha(-1) in 1960 and 16.55 t C ha(-1) in 1995. Total C store in the whole live woody biomass was estimated at 22.77 t C ha(-1) in 1996. The total flux of C from the atmosphere into the forest and woodland ecosystems driven by primary productivity was about 1.46 t C ha(-1)(or 30.2 Mt C) in 1996. The estimated net release of C from the forest and woodland ecosystems of Turkey to the atmosphere was about 1.34 t C ha(-1)(or 21.5 Mt C) in 1996. When C released was taken into account, net ecosystem sequestration (NES) resulted in 0.12 t C ha(-1) per year. Such analytical tools as national forest C budgets are needed to improve our preventive and mitigative strategies for dealing with global climate change.