Losses to life and property from unplanned fires (wildfires) are forecast to increase because of population growth in peri-urban areas and climate change. In response, there have been moves to increase fuel reduction—clearing, prescribed burning, biomass removal and grazing—to afford greater protection to peri-urban communities in fire-prone regions. But how effective are these measures? Severe wildfires in southern Australia in 2009 presented a rare opportunity to address this question empirically. We predicted that modifying several fuels could theoretically reduce house loss by 76%–97%, which would translate to considerably fewer wildfire-related deaths. However, maximum levels of fuel reduction are unlikely to be feasible at every house for logistical and environmental reasons. Significant fuel variables in a logistic regression model we selected to predict house loss were (in order of decreasing effect): (1) the cover of trees and shrubs within 40 m of houses, (2) whether trees and shrubs within 40 m of houses was predominantly remnant or planted, (3) the upwind distance from houses to groups of trees or shrubs, (4) the upwind distance from houses to public forested land (irrespective of whether it was managed for nature conservation or logging), (5) the upwind distance from houses to prescribed burning within 5 years, and (6) the number of buildings or structures within 40 m of houses. All fuel treatments were more effective if undertaken closer to houses. For example, 15% fewer houses were destroyed if prescribed burning occurred at the observed minimum distance from houses (0.5 km) rather than the observed mean distance from houses (8.5 km). Our results imply that a shift in emphasis away from broad-scale fuel-reduction to intensive fuel treatments close to property will more effectively mitigate impacts from wildfires on peri-urban communities.

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Large trees are considered keystone structures in agricultural and forestry production landscapes, but research demonstrating this in urban landscapes is urgently needed. If large trees are keystone structures in urban parks, it is imperative that this is recognized in policy to ensure their ongoing existence. We studied the role of large native trees for birds in urban parks in Canberra, Australia. We found that (1) large trees had a consistent, strong, and positive relationship with five measures of bird diversity, and (2) as trees became larger in size, their positive effect on bird diversity increased. Large urban trees are therefore keystone structures that provide crucial habitat resources for wildlife. Hence, it is vital that they are managed appropriately. With evidencebased tree preservation policies that recognize biodiversity values, and proactive planning for future large trees, the protection and perpetuation of these important keystone structures can be achieved.

A meta-analysis of fauna and flora species richness and abundance in plantations and pasture lands. Biological conservation. Volume: 143Number: 3, pp 545-554. http://dx.doi.org/10.1016/j.biocon. 2009.11.030 Access to the published version may require journal subscription.Published with permission from: ELSEVIER We conducted a systematic global review of differences between timber plantations and pasture lands in terms of animal and plant species richness and abundance, and assessed the results using meta-analysis techniques. Our principal aim was to test the hypothesis that plantations contain higher species richness or abundance than pasture. Of the 1967 studies of potential relevance, 66 provided biological monitoring information and 36 met the requirements for meta-analyses. Sufficient data were available for meta-analyses to be conducted comparing the species richness and abundance of plantations and pasture lands for five taxonomic groups: plants, invertebrates, reptiles/amphibians, mammals, and birds. Within each taxon there was considerable variation in the difference between species richness and abundance between plantations and pasture lands. Birds and reptile/amphibians exhibited significantly higher species richness, and mammals exhibited significantly higher abundance, in plantations than in pasture lands which lacked remnant vegetation. Reptile/amphibian species richness was significantly higher in plantations in general. No significant differences in species richness were found for mammals, plants, or invertebrates, and no significant differences in abundance were found for birds, reptiles/amphibians, invertebrates, or plants. It is only within the presence of taxonomic caveats (ie. reptiles/amphibians), or specific landscape features (ie. absence of remnant vegetation within pasture), that it can be concluded that plantations support higher species richness or abundance than pasture land. We emphasize that caution is warranted when making general statements about the inherent biodiversity value of diverse and broadly-defined land-uses. 3Plantations and biodiversity 1

The experiments presented in this paper support the idea that the output of small lymphocytes from the thoracic duct of the rat (about 10 9 /day) is normally maintained by a large-scale re-circulation of cells from the blood to the lymph. It has been shown that the main channel from blood to lymph lies with in the lymph nodes and that small lymphocytes enter the nodes by crossing the walls of a specialized set of blood vessels, the post-capillary venules. In order to trace the fate of small lymphocytes, cells from the thoracic duct of rats were incubated for 1 h in vitro with tritiated adenosine. This labelled the RNA of about 65% of the small lymphocytes and more than 95% of the large lymphocytes; it also labelled the DNA of a proportion of the large lymphocytes. The mixture of small and large labelled lymphocytes was transfused into the blood of two groups of rats which belonged to the same highly inbred strain as the cell donors. At various times after the transfusions the thoracic ducts in one group of rats were cannulated to determine the proportion of labelled cells which could be recovered in the lymph; at corresponding times, the rats in the other group were killed and autoradiographs prepared from their tissues to determine the location of the labelled cells. The radioactive label in the RNA of small lymphocytes was stable enough to ensure that the labelled small lymphocytes which were recovered in the lymph several days after a transfusion were those which had originally been transfused into the blood. When the thoracic duct was cannulated 20 to 27 h after a transfusion, about 70% of the labelled small lymphocytes which had been transfused into the blood could be recovered from the thoracic duct over a 5-day period of lymph collection. During the first 36 to 48 h after cannulation, while the total output of small lymphocytes was falling rapidly, the proportion of labelled cells in the lymph remained approximately constant. The pool of the animal’s own cells with which the labelled cells had mixed contained between 1·5 and 2 × 10 9 small lymphocytes; this was identified as the re-circulating pool. An autoradiographic study showed that after their transfusion into the blood the labelled small lymphocytes ‘homed’ rapidly and in large numbers into the lymph nodes, the white pulp of the spleen and the Peyer’s patches of the intestine. The concentration of labelled cells in other tissues was trivial in comparison. Labelled small lymphocytes were seen penetrating the endothelium of the post-capillary venules in the lymph nodes within 15 min of the start of a transfusion; they were traced into the cortex of the nodes and finally into the medullary lymph sinuses. Labelled small lymphocytes did not migrate into the adult thymus but a few entered the thymus of newborn rats. It was concluded that the re-circulating pool of small lymphocytes was located in the lymphoid tissue, the thymus excepted, and that the rapid ‘homing’ of cells into the lymph nodes had its basis in the special affinity of small lymphocytes for the endothelium of the post-capillary venules. The interpretation of these experiments was not complicated by the presence of large, as well as of small lymphocytes in the suspensions of labelled cells which were transfused. Other experiments, in which the large lymphocytes alone were labelled with tritiated thymidine, showed that most of them migrated from the blood into the wall of the gut where they assumed the appearance of primitive plasma cells; very few divided to form small lymphocytes.

Cycling is recognised as a sport in which there is a high incidence of poor bone health. Sweat calcium losses may contribute to this.PurposeTo examine whether a calcium-rich pre-exercise meal attenuates exercise-induced perturbations of bone calcium homeostasis caused by maintenance of sweat calcium losses.MethodsUsing a randomized, counterbalanced crossover design, 32 well-trained female cyclists completed two 90 min cycling trials separated by 1 day. Exercise trials were preceded 2 hours by either a calcium-rich (1352 ± 53 mg calcium) dairy based meal (CAL) or a control meal (CON; 46 ± 7 mg calcium). Blood was sampled pre-trial; pre-exercise; and immediately, 40 min, 100 min and 190 min post-exercise. Blood was analysed for ionized calcium and biomarkers of bone resorption (Cross Linked C-Telopeptide of Type I Collagen (CTX-I), Cross Linked C-Telopeptide of Type II Collagen (CTX-II), Parathyroid Hormone (PTH), and bone formation (Procollagen I N-Terminal Propeptide (PINP)) using the established enzyme-linked immunosorbent assay technique.ResultsPTH and CTX-I increased from pre-exercise to post-exercise in both conditions but was attenuated in CAL (p < 0.001). PTH was 1.55 [1.20, 2.01] times lower in CAL immediately post-exercise and 1.45 [1.12, 1.88] times lower at 40 min post-exercise. CTX-I was 1.40 [1.15, 1.70] times lower in CAL at immediately post-exercise, 1.30 [1.07, 1.57] times lower at 40 min post-exercise and 1.22 [1.00, 1.48] times lower at 190 min post-exercise (p < 0.05). There was no significant interaction between pre-exercise meal condition and time point for CTX-II (p = 0.732) or PINP (p = 0.819).ConclusionThis study showed that a calcium-rich pre-exercise breakfast meal containing ~1350 mg of calcium consumed ~90 min before a prolonged and high intensity bout of stationary cycling attenuates the exercise induced rise in markers of bone resorption – PTH and CTX-I.Trial RegistrationAustralian New Zealand Clinical Trials Registry ACTRN12614000675628

Marker-based methods for estimating heritability and genetic correlation in the wild have attracted interest because traditional methods may be impractical or introduce bias via G 3 E effects, mating system variation, and sampling effects. However, they have not been widely used, especially in plants. A regression-based approach, which uses a continuous measure of genetic relatedness, promises to be particularly appropriate for use in plants with mixed-mating systems and overlapping generations. Using this method, we found significant narrow-sense heritability of foliar defense chemicals in a natural population of Eucalyptus melliodora. We also demonstrated a genetic basis for the phenotypic correlation underlying an ecological example of conditioned flavor aversion involving different biosynthetic pathways. Our results revealed that heritability estimates depend on the spatial scale of the analysis in a way that offers insight into the distribution of genetic and environmental variance. This study is the first to successfully use a marker-based method to measure quantitative genetic parameters in a tree. We suggest that this method will prove to be a useful tool in other studies and offer some recommendations for future applications of the method.

BackgroundBig environmental disturbances have big ecological effects, yet these are not always what we might expect. Understanding the proximate effects of major disturbances, such as severe wildfires, on individuals, populations and habitats will be essential for understanding how predicted future increases in the frequency of such disturbances will affect ecosystems. However, researchers rarely have access to data from immediately before and after such events. Here we report on the effects of a severe and extensive forest wildfire on mortality, reproductive output and availability of key shelter resources for an arboreal marsupial. We also investigated the behavioural response of individuals to changed shelter resource availability in the post-fire environment.Methodology/Principal FindingsWe fitted proximity-logging radiotransmitters to mountain brushtail possums (Trichosurus cunninghami) before, during and after the 2009 wildfires in Victoria, Australia. Surprisingly, we detected no mortality associated with the fire, and despite a significant post-fire decrease in the proportion of females carrying pouch young in the burnt area, there was no short-term post-fire population decline. The major consequence of this fire for mountain brushtail possums was the loss of over 80% of hollow-bearing trees. The types of trees preferred as shelter sites (highly decayed dead standing trees) were those most likely to collapse after fire. Individuals adapted to resource decline by being more flexible in resource selection after the fire, but not by increased resource sharing.Conclusions/SignificanceDespite short-term demographic resilience and behavioural adaptation following this fire, the major loss of decayed hollow trees suggests the increased frequency of stand-replacing wildfires predicted under climate change will pose major challenges for shelter resource availability for hollow-dependent fauna. Hollow-bearing trees are typically biological legacies of previous forest generations in post-fire regrowth forests but will cease to be recruited to future regrowth forests if the interval between severe fires becomes too rapid for hollow formation.