Patterns of harvesting foliage and bark from the multipurpose tree Khaya senegalensis in Benin: Variation across ecological regions and its impacts on population structure

Non-timber forest products (NTFPs) represent important resources for millions of communities worldwide. Concerns over NTFP overexploitation has led to a growing number of studies on the ecological impacts of harvest. Few studies however, have addressed species harvested for multiple parts or investigated how spatial variation affects harvest patterns and their impacts. We documented rates and patterns of pruning and debarking and their impacts on density and population structure, for 12 populations of the multiuse tree, Khaya senegalensis (Meliaceae) in two ecological regions (Sudano-Guinean versus Sudanian) of Benin, West Africa. Half of the populations had low or no harvest and half were highly harvested. Patterns of pruning and debarking were size-specific, with harvesters tending to prefer larger trees. Foliage harvest pressures were very high across both regions, with >70% of trees harvested for 100% of their crowns. A significantly greater proportion of trees were harvested for foliage in the wetter Sudano-Guinean region than in Sudanian region. The reverse was true for the proportion of foliage and bark-harvested per tree. In the Sudano-Guinean region, high harvest populations had significantly lower densities of seedlings and saplings than low harvest populations. The size-class distribution coefficient of skewness was significantly correlated with rainfall, habitat, and soil type. Variation in harvesting patterns and their ecological impacts can be explained in large part by differences in water availability between the two regions. Effective conservation plans for K. senegalensis require close consideration of the environmental and land-use context in which populations occur.     

Chronic toxicity of unresolved complex mixtures (UCM) of hydrocarbons in marine sediments

Background, Aim and Scope  Unresolved complex mixtures (UCM) of hydrocarbons, containing many thousands of compounds which cannot be resolved by conventional gas chromatography (GC), are common contaminants of sediments but little is known of their potential to affect sediment-dwelling organisms. Evidence exists for reduced health status in mussels, arising from aqueous exposure to aromatic UCM components acting through a narcotic mode of action. However, UCM contaminants in sediments may not be sufficiently bioavailable to elicit toxic effects. The aim of our study was therefore to measure the sublethal effects of chronic exposure to model UCM-dominated oils at environmentally realistic concentrations and compare this to effects produced by a UCM containing weathered crude oil. A further aim was to determine which, if any, fractions of the oils were responsible for any observed toxicity. Materials and Methods  Whole oils were spiked into estuarine sediment to give nominal concentrations of 500 μg g⁻¹ dry weight. Juveniles of the estuarine amphipod Corophium volutator were exposed to the contaminated sediment for 35 days and their survival, growth rate and reproductive success quantified. Using an effect-directed fractionation approach, the oils were fractionated into aliphatic and two aromatic fractions by open column chromatography and their toxicity assessed by further chronic exposures using juvenile C. volutator. Results  The growth rates of amphipods were reduced following exposure to the oils although this was only statistically significant for the weathered oil; reproductive success was reduced by all oil exposures. Sediment spiked with UCM fractions also caused reduced growth and reproduction but no particular fraction was found to be responsible for the observed toxicity. Survivorship was not affected by any oil or fraction. Discussion  The study showed that chronic exposure to sediments contaminated by UCM-dominated oils could have population level effects on amphipods. The observed effects could not be explained by hydrocarbons resolved by conventional GC and effects were similar for both UCM-dominated and weathered oils. All of the fractions appeared to contribute to the observed effects; this is in contrast to previous research which had shown that an aliphatic UCM did not cause adverse effects in mussels. Conclusions  To our knowledge, this is the first study to demonstrate population-level effects arising from exposure to sediments contaminated by realistic environmental concentrations of UCM hydrocarbons. The results are consistent with many compounds, at very low individual concentrations, contributing towards the overall observed toxicity. Recommendations  Risk assessments of contaminated sediments should take into account the contribution towards the potential for toxic effects from UCM hydrocarbons. Studies into sediment contamination should report both aliphatic and aromatic UCM concentrations to aid risk assessments. ESS-Submission Editor: Henner Hollert (hollert@uni-heidelberg.de) This paper has been developed from a presentation at SETAC Europe 16^th Annual Meeting 2006 held at the The Hague, The Netherlands.     

Organic amendments and urea nitrogen effects the growth and nutrient content of fenugreek (Trigonella foenumgraecum) and goat pea (Securigera securidaca)

Abstract

In Iran, the recent spike in herbal medicines has led to a corresponding price increase. Therefore, these montane species are now widely field cultivated. Medicinal plant consumers strongly prefer organically grown plants, and farmers are responding to this market. However, the effects of organic amendments on medicinal plant nutrient content and yield have been poorly studied. Therefore, this study measured the effects of different organic treatments on the growth of fenugreek and goat pea. Plants were grown to compare the effects of composted municipal waste (CMW), vermicompost (VC), and urea nitrogen (N) to untreated field soil (C0). Germination percentage was significantly higher in urea N (76.5%), CMW (75.5%), and VC (51.6%) compared to C0 (36.3%). Fenugreek performed better in organic amendment treatments than goat pea. Urea N also increased fenugreek plant dry matter significantly compared to C0, but this increment was not as high as CMW or VC. Plants grown in VC had higher whole plant N content (3.2%) than those grown in CMW (2.8%) and plants grown in urea N (2.6%). Plants treated with CMW (8613?mg kg^?1) and VC (8503?mg kg^?1) had a significantly higher P content than those treated with N (7430?mg kg^?1) or C0 control grown (7236?mg kg^?1). Application of VC significantly increased plant K content (2483?mg kg^?1) compared to CMW (1850?mg kg^?1), N (1750?mg kg^?1), and C0 control (1716?mg kg^?1). Even without fertilization, both plant species contained a considerable amount of micronutrient elements.     

Resistance of Organic Horizon to Acidification from Snowmelt in Podzolic Soil of the Kola Peninsula (6 pp)

Background  

The Kola Peninsula (the most northern region of the European fringe of Russia) is covered with podzolic soil and is considered the most sensitive area to acidification in Europe because of the low input rate of base cations by weathering. About 300 thousand tons of SO2 are annually emitted from stationary sources in this region. Acidic precipitation accumulates in the snow during winter, and acidic water suddenly flushes into the soil during spring snowmelt (so-called acid shock). It is therefore important to assess how the acid-sensitive podzol responds to an intensive increase in acid load. The main purpose of this paper is to show the observed data rather than to provide an analytical interpretation of the observed phenomenon.     

Systemic coccidioidomycosis in a llama cria native to Missouri

A 3-mo-old male llama was examined because of a 4-wk history of lethargy and ill thrift. Clinical examination revealed subcutaneous masses in the left prescapular and right inguinal regions, mild ataxia, a slight head tilt to the right, and right ear droop. The cria died before clinical workup was complete. At autopsy, there was generalized lymphadenomegaly, a hepatic nodule, a midbrain mass causing rostral compression of the cerebellum, and internal hydrocephalus. Microscopic findings included pyogranulomatous lymphadenitis, meningoencephalitis, hepatitis, and bronchopneumonia. Intralesional fungal spherules, most consistent with Coccidioides spp., were identified in the lymph nodes, lung, and brain. Fungal culture, single-nucleotide variation genotyping real-time PCR, and DNA sequencing confirmed Coccidioides posadasii. The dam of the cria was native to Arizona and had been moved to Missouri ~2.5 y previously. Agar gel immunodiffusion assay of the herd revealed that only the dam was positive for Coccidioides spp.; 6 herdmates were negative. Computed tomography of the dam revealed multiple nodules within the lungs and liver, which were presumed to be an active coccidioidomycosis infection. This case of systemic coccidioidomycosis in a llama native to Missouri was presumably acquired by vertical transmission from the dam.     

Both mu and delta opiate receptors exist on the same neuron

Low concentrations of the relatively selective opiate receptor agonists dihydromorphine and normorphine (mu receptor agonists) and D-Ala 2-D-Leu 5-enkephalin (a delta receptor agonist) were applied to single enteric neurons while the frequency of action potential firing was recorded. Most neurons that were inhibited by the mu agonists were also inhibited by the delta agonist, but the two receptors could be distinguished by the higher concentration of naloxone required to antagonize the delta agonist. The results indicate that enteric neurons bear both mu and delta receptors and that cell firing is inhibited if either receptor type is activated.     

Invertebrate diversity associated with a shallow rhodolith bed in the Mediterranean Sea (Mar Piccolo of Taranto,south-east Italy)

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