The mysid fauna of the River Tamar Estuary was sampled monthly between January and December 1989. The following species of mysid were found In the estuary. MosopodOPSIS slabborl, Noomysis Intogor, Praunus fioxuosus and SchistomysIs omata. The latter two species, present In low densities throughout tho year, occupied the lower, more salino (>30%o) parts of the estuary, whereas M. slabborl and N. Intogor were abundant In the upper estuary (0.5-30%o). Mosopodopsis slabbori produced between two and three generations per year, and showed a pattern of alternating early and lato-brooding generations. A maximum growth rate for this species was 0.24 mm d" for thd fastestgrowing summer cohort and annual production estimates ranged between a moan value of 50.6 mg dry weight m*3 y'and a maximum (based on the highest density measured on each sampling date) of 241.4 mg dry weight m*3 y'. This Is the first time that growth and production have been estimated for M. slabbort. There were marked seasonal and spatIal changes In abundance and distribution of M. slabborl. Abundance Increased from a low of <50 m-3 In winter to a maximum of 354 m3 (100 mg dry weight m3 ) In summer. Salinity appeared to be the major variable Influencing spatial distribution and the different agoclasses of M. slabborl had clearly Identifiable and distinct salinity distributions. There was evidence of a seasonal (winter) down-ostuary movement of the M. slabborl population. The ostuadno distribution of N. Intogorovorlappod with that of M. slabborl, but N. Intogor had a wider salinity distribution and colonisod lower salinity regions of the estuary (<5%*.) than M. slabborl. Largo Immature and adult N. Intogorworo not sampled successfully In those surveys, suggesting that those stages exhibited a different behaviour from other lifehistory stages. The physiology undorlying the wide salinity tolerance of A Intogor was examined. NoomysIsintogormaintainod Its blood hyporosmotictosoawatorln the salinity range 0.5 to 20%*. and the haomolymph responded rapidly to acute changes In salinity. This high osmorogulatory ability was correlated with changes In amino acid concontratlons, and glutamino, glycino, taudno and alanino were Identified as important osmoolloctors In this species.

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<p> High-latitude ecosystems store large amounts of carbon in soil organic matter and are among the most vulnerable to climate change. In particular, fire severity and frequency are increasing in boreal ecosystems, and these events are likely to have direct and indirect effects on climate feedbacks via increased emission of carbon (C) from soil and changes in vegetation composition, respectively. In this study we created experimental burns of three severities in the northeastern Siberian arctic, near Cherskiy, RU, and quantified dissolved C, nitrogen (N), and phosphorus (P), and microbial respiration and extracellular enzyme activities at 1-day, 8-days, and 1-year post-fire. </p><p> Our objective was to determine how fire affects C, N, and P pools, soil microbial processes, and how these effects scale across severity and time since fire. We found labile C and nutrients increased immediately post-fire, but appeared similar to unburned controls within a week. Phosphorus alone remained elevated through 1-year post-fire. Leucine aminopeptidase activities initially increased with fire severity, but by 1-year, activities decreased with fire severity at a rate an order of magnitude faster. Fire severity suppressed phosphatase and ?-glucosidase activities at all time points. Soil respiration was reduced by half in high severity plots 1-year post-fire, while net rates of N mineralization increased by an order of magnitude. We found that changes in soil C and nutrient pools, soil respiration, and net N mineralization rates responded in a threshold-fashion to fire severity, although P was uncoupled from C and N by changing at a distinct severity threshold. Extracellular enzyme activities and edaphic variables scaled linearly with fire severity. The interaction of threshold and linear response curves to fire severity may help explain the variability across studies in soil microbial community responses to fire. Microbial communities recovering from more severe fires have the possibility to decrease future ecosystem C losses through reduced respiration. The changing fire regime in permafrost ecosystems has the potential to alter soil microbial community dynamics, the retention of nutrients, and the stoichiometry of C, N, and P availability.</p>

<p> Biodiversity has decreased due to anthropogenic activities, and extinction rates are currently one hundred to one thousand times greater than the background rate. While the connection between deforestation and biodiversity loss is well documented within tropical rainforest ecosystems, comparatively little is known about the effects of desertification on biodiversity in dryland ecosystems. Drylands, which cover nearly half the terrestrial surface and are highly vulnerable to desertification, are among the most endangered ecosystems. To understand how biodiversity responds to environmental degradation in these fragile ecosystems, I studied arthropod diversity within a human-modified landscape suffering from deforestation and desertification in the Sahel of western Senegal. My specific objective was to determine whether arthropod, beetle, spider and ant diversity differed between protected areas of tropical dry forest and surrounding communal lands suffering from desertification. I established 12 quadrats spaced homogenously throughout each protected area as well as adjacent communal land at three different locations (Beersheba, Bandia and Ngazobil). Within each quadrat, I measured canopy closure, characterized vegetation and collected arthropods using pitfall traps during the 2014 dry (May) and rainy (September) seasons.</p><p> I collected 123,705 arthropods representing 733 morphospecies, 10,849 beetles representing 216 morphospecies, 4,969 spiders representing 91 morphospecies and 59,183 ants representing 45 morphospecies. Results showed protected areas contained greater arthropod and spider diversity than communal lands, beetle diversity varied depending on location and season, and communal lands contained greater ant diversity than protected areas (<i>P</i> &le; 0.05). My results illustrate the importance of a multi-taxa approach in understanding biodiversity response to anthropogenic disturbances. Conserving arthropod diversity in the Sahel will require the creation and preservation of more protected areas of a variety of sizes and successional stages as well as the adoption and extension of land-restorative techniques such as Zai and farmer managed natural regeneration (FMNR).</p>

Lactation provides the singular source of nourishment to the offspring of mammals. This nutrition source also contains a diverse microbiota affecting the development and health of the newborn. Here, we examined the milk microbiota in water deer (Hydropotes inermis, the most primitive member of the family Cervidae), reindeer (Rangifer tarandus, the oldest semi-domesticated cervid), and the dairy goat (Capra aegagrus, member of the family Bovidae), to determine if common milk microbiota species were present across all three ruminant species. The results showed that water deer had the highest bacterial diversity, followed by reindeer, and then goat. Unifrac distance and correspondence analyses revealed that water deer harbored an increased abundance of Pseudomonas spp. and Acinetobacter spp., while milk from reindeer and goat was dominated by unclassified bacteria from the family Hyphomicrobiaceae and Bacillus spp., respectively. These data indicate significant differences in the composition of milk-based bacterial communities. The presence of Halomonas spp. in three distinct co-occurrence networks of bacterial interactions revealed both common and unique features in milk niches. These results suggest that the milk of water deer and reindeer harbor unique bacterial communities compared with the goat, which might reflect host microbial adaptation caused by evolution.

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