A field guide for aging passerine nestlings using growth data and predictive modeling

Background: Accurate nestling age is valuable for studies on nesting strategies, productivity, and impacts on repro-ductive success. Most aging guides consist o...     

Enhanced fitness conferred by naturally occurring variation in the circadian clock

Natural variation in clock parameters is necessary for the circadian clock to contribute to organismal fitness over a broad geographic range. Considerable variation is evident in the period, phase, and amplitude of 150 Arabidopsis accessions, and the period length is correlated with the day length at the latitude of origin, implying the adaptive significance of correctly regulated circadian timing. Quantitative trait loci analysis of recombinant inbred lines indicates that multiple loci interact to determine period, phase, and amplitude. The loss-of-function analysis of each member of the ARABIDOPSIS PSEUDO-RESPONSE REGULATOR family suggests that they are candidates for clock quantitative trait loci.     

Lizard distribution patterns in the Tumut fragmentation “Natural Experiment” in south-eastern Australia

Lizard distribution patterns were examined in a fragmented plantation landscape in south-eastern Australia. Regression modelling was used to relate ecological variables to (1) lizard species richness, (2) lizard species composition, and (3) the presence or abundance of selected lizard species. Ecological variables covered four broad domains that affect animals: climate, space, shelter and food availability.Lizard species richness was highest at mid-elevation sites, and at locations with a large amount of native forest within 1000 m. A major change in lizard species composition was associated with elevation, the proportion of native forest within 1000 m of a site, and the abundance of springtails. The change in species composition coincided with a range of individualistic responses to environmental conditions by different lizard species. For example, with respect to shelter availability, old logs were related to the garden skink Lampropholis guichenoti, shrubs were related to the delicate skink L. delicata, and rocks were related to the red-throated skink Bassiana platynota. The garden skink was most abundant at low elevations, the delicate skink was most likely to occur at intermediate elevations, and the mountain log skink Pseudemoia entrecasteauxii was most likely to occur at high elevations. The garden skink was most abundant in areas surrounded by little native forest, whereas Maccoy’s skink Nannoscincus maccoyi and Coventry’s skink Niveoscincus coventryi were more abundant or likely to occur in areas whose context was dominated by native forest.Because animal species may respond individualistically to gradients of climate, space, shelter and food availability, continuum theory (as developed for plant ecology) may be a useful complement to fragmentation theory to explain distribution patterns. To maintain lizard diversity in the study area, it will be important to maintain maximum habitat heterogeneity at the landscape and microhabitat scales. For species otherwise threatened by plantation development, large, fairly undisturbed areas of eucalypt forest will be particularly important.     

Bioavailability and efficacy of vitamin D2 from UV-irradiated yeast in growing, vitamin D-deficient rats

New food sources are needed to bridge the gap between vitamin D intake and recommended intake. We assessed the bioavailability and efficacy of vitamin D in an 8 week dose-response study of bread made with vitamin D2-rich yeast compared to vitamin D3 in growing, vitamin D-deficient rats. Plasma 25-hydroxyvitamin D (25OHD) levels increased in a curvilinear, dose-dependent manner with both forms of vitamin D, but rats fed vitamin D2-rich yeast achieved lower levels than rats fed vitamin D3. Rats fed the highest doses of vitamin D had significantly greater (p<0.05) trabecular BMC, BMD, bone volume, and connectivity density, and greater midshaft total cross-sectional area, compared to rats on the vitamin D-deficient diets, with no significant difference due to vitamin D source. Vitamin D2-rich yeast baked into bread is bioavailable and improves bone quality in vitamin D-deficient animals.     

REINTEGRATION OF CROP-LIVESTOCK SYSTEMS IN EUROPE: AN OVERVIEW

• ICLS combines the benefits of specialization with increased resilience of the system.• Clear opportunities but also barriers for ICLS were observed.• ICLS need to be embedded within future environmental legislation.• ICLS systems with a range of intensities are needed to support a biodiverse landscape.Ongoing specialization of crop and livestock systems provides socioeconomic benefits to the farmer but has led to greater externalization of environmental costs when compared to mixed farming systems. Better integration of crop and livestock systems offers great potential to rebalance the economic and environmental trade-offs in both systems. The aims of this study were to analyze changes in farm structure and review and evaluate the potential for reintegrating specialized intensive crop and livestock systems, with specific emphasis on identifying the co-benefits and barriers to reintegration. Historically, animals were essential to recycle nutrients in the farming system but this became less important with the availability of synthetic fertilisers. Although mixed farm systems can be economically attractive, benefits of scale combined with socio-economic factors have resulted in on-farm and regional specialization with negative environmental impacts. Reintegration is therefore needed to reduce nutrient surpluses at farm, regional and national levels, and to improve soil quality in intensive cropping systems. Reintegration offers practical and cost-effective options to widen crop rotations and promotes the use of organic inputs and associated benefits, reducing dependency on synthetic fertilisers, biocides and manure processing costs. Circular agriculture goes beyond manure management and requires adaptation of both food production and consumption patterns, matching local capacity to produce with food demand. Consequently, feed transport, greenhouse gas emissions, nutrient surpluses and nutrient losses to the environment can be reduced. It is concluded that reintegration of specialized farms within a region can provide benefits to farmers but may also lead to further intensification of land use. New approaches within a food system context offer alternatives for reintegration, but require strong policy incentives which show clear, tangible and lasting benefits for farmers, the environment and the wider community.