Search results for "Environmental chemistry"
showing 10 items of 3248 documents
Convergences and divergences between scientific and Indigenous and Local Knowledge contribute to inform carnivore conservation
2021
There is increasing recognition that diverse knowledge systems can work in mutually enriching ways and that Indigenous and Local Knowledge (ILK) can enhance biodiversity conservation. However, studies using scientific knowledge and ILK in a complementary manner, and acknowledging convergent and especially divergent insights have remained limited. In this study, we contrasted proxies of abundances and trends of threatened and conflict-prone carnivores (caracal, cheetah, jackal, lion, leopard, spotted hyaena, striped hyaena) derived separately from scientific knowledge and ILK. We conducted camera trapping, track surveys and semi-structured interviews with local pastoralists from northern Ken…
Insecticide residues in cotton soils of Burkina Faso and effects of insecticides on fluctuating asymmetry in honey bees (Apis mellifera Linnaeus).
2011
8 pages; International audience; Four insecticides (acetamiprid, cypermethrin, endosulfan and profenofos) are used quarterly in the cotton-growing areas of Burkina Faso, West Africa. These insecticides were investigated in soils collected from traditionally cultivated and new cotton areas. Also, the effects of insecticide exposure on the developmental instability of honey bees, Apis mellifera, were explored. In soil samples collected three months after insecticide treatments, endosulfan and profenofos concentrations varied in the range of 10-30μgkg(-1) in the traditionally cultivated zones and 10-80μgkg(-1) in the new cotton zones, indicating a pollution of agricultural lands. However, only…
Pest management under climate change: The importance of understanding tritrophic relations.
2018
11 pages; International audience; Plants and insects depend on climatic factors (temperature, solar radiation, precipitations, relative humidity and CO2) for their development. Current knowledge suggests that climate change can alter plants and insects development and affect their interactions. Shifts in tritrophic relations are of particular concern for Integrated Pest Management (IPM), because responses at the highest trophic level (natural enemies) are highly sensitive to warmer temperature. It is expected that natural enemies could benefit from better conditions for their development in northern latitudes and IPM could be facilitated by a longer period of overlap. This may not be the ca…
Climate–human interactions contributed to historical forest recruitment dynamics in Mediterranean subalpine ecosystems
2020
Long-term tree recruitment dynamics of subalpine forests mainly depend on temperature changes, but little is known about the feedbacks between historical land use and climate. Here, we analyze a southern European, millennium-long dataset of tree recruitment from three high-elevation pine forests located in Mediterranean mountains (Pyrenees, northeastern Spain; Pollino, southern Italy; and Mt. Smolikas, northern Greece). We identify synchronized recruitment peaks in the late 15th and early 16th centuries, following prolonged periods of societal and climate instability. Major European population crises in the 14th and 15th centuries associated with recurrent famines, the Black Death pandemic,…
Drought and its legacy modulate the post-fire recovery of soil functionality and microbial community structure in a Mediterranean shrubland.
2019
The effects of drought on soil dynamics after fire are poorly known, particularly its long-term (i.e., years) legacy effects once rainfall returns to normal. Understanding this is particularly important for nutrient-poor soils in semi-arid regions affected by fire, in which rainfall is projected to decrease with climate change. Here, we studied the effects of post-fire drought and its legacy on soil microbial community structure and functionality in a Cistus-Erica shrubland (Spain). Rainfall total and patterns were experimentally modified to produce an unburned control (natural rainfall) and four burned treatments: control (natural rainfall), historical control (long-term average rainfall),…
Survey on the presence of non-dioxine-like PCBs (NDL-PCBs) in loggerhead turtles (Caretta caretta) stranded in south Mediterranean coasts (Sicily, So…
2017
A total of 71 loggerhead turtles (Caretta caretta) stranded along the coasts of Sicily (Southern Italy) were examined for non-dioxine like polychlorinated biphenyl (NDL-PCB) levels in muscle and adipose tissue by a gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) method. The results revealed 6 high-indicator congener (∑6 PCBIND ) levels in 45% of the loggerhead turtles examined, with mean values of 980.39 ± 2508.39 ng/g wet weight in adipose tissue and 102.53 ± 238.58 ng/g wet weight in muscle tissue. The hexachloro and heptachloro PCB congeners were the most abundant in both the sample types. The highest NDL-PCB levels were reached in an adipose tissue sample of a loggerhe…
Organic nitrogen steadily increasing in Norwegian rivers draining to the Skagerrak coast
2020
AbstractDeclining atmospheric nitrogen (N) deposition, through reduction in the direct input of inorganic N, may result in less inorganic N being leached from soils to freshwaters (dissolved inorganic N = DIN). Declining sulphur deposition, through reducing the ionic strength in soil water, increases the solubility and mobility of organic soil compounds and may result in increased leaching of organically bound N to freshwaters (total organic N = TON). It is unknown to which extent these two independents and opposing trends, i.e. DIN decline versus TON increase, may affect the nutrient balance (load, stoichiometry) of river water draining into coastal zones. By combining long-term atmospheri…
The effects of absolute and relative nutrient concentrations (N/P) on phytoplankton in a subtropical reservoir
2020
Abstract The elemental composition of phytoplankton is a critical factor for primary production and nutrient recycling. The increase anthropogenic nutrient input into freshwater ecosystems is affecting phytoplankton assemblage structure and its stoichiometry. Reservoirs of South China generally show low level of phosphate and it is not clear how phytoplankton can grow and occasionally bloom in such conditions. Therefore, an indoor experiment was conducted to investigate the response of natural phytoplankton communities to 25 levels of supplied nitrogen to phosphorus ratios (N/P), arising from the combination of 5 levels of N and P. Our aim was to check the effects of absolute and relative N…
Aquatic effects of peat extraction and peatland forest drainage: a comparative sediment study of two adjacent lakes in Central Finland
2016
The aquatic effects of forestry practices and peat extraction continue to cause serious concerns. The effect mechanisms of peat extraction on water quality and aquatic ecology of the receiving surface waters are well known, but the impacts are often difficult to differentiate from those of forest management. A pairwise temporal sediment study was conducted on two adjacent lakes in Central Finland to study whether the unique effects of peat extraction can be detected in an area of intensive forest drainage. Both lakes are affected by forestry, but the reference lake has no history of peat extraction in its watershed. The deepest parts of the lakes were cored through the lacustrine sediments,…
Spatial distribution, contamination assessment and potential ecological risk of some trace metals in the surface sediments of the Gulf of Tunis, Nort…
2021
To evaluate the trace metals contamination status in the Gulf of Tunis, forty one sediment samples were analyzed using different approaches. According to certain contamination and ecological risk indices (Contamination Factor, Geoaccumulation index and Ecological risk index), Hg has the highest contamination level while pollution by Ni, Pb, Cd and Cr was absent. The highest concentrations of trace metals were found in sediments collected from the offshore and coastal areas located opposite the main exchange points with the gulf particularly, the Mejerda and Meliane Rivers, the Khalij Channel, Ghar El Melh and El Malah lagoons, Tunis Lake and Sebkhat Ariana. However, further ecological indic…