Vegetation responses to the first 20 years of cattle grazing in an Australian desert

Existing theoretical frameworks suggest three predictions relevant to grazing effects in Australian aridlands: grazing has a negative but moderate effect on plant species richness; a separate "state" resulting from degradation caused by extreme grazing will be evident; some plant species will have a strong association with grazing relief refuges that have only ever been subject to light grazing. These predictions were examined in the dune swales of an Australian desert, with data on herbaceous species collected along transects up to 14 km from artificial water points between four and 33 years old. A cumulative grazing index was constructed utilizing both the spatial occupation patterns of cattle and the length of exposure. Despite restricting sampling to a narrow habitat, silt/clay content and soil pH influence floristic patterns independent of grazing. The analysis of quadrat data in relation to grazing revealed almost no patterns in plant cover, species richness (at two different scales), or abundance across plant life-form groups. Five species had an increasing response, and seven a decreasing response, while the only species restricted to areas of extremely low grazing pressure was sufficiently rare that it could have occurred there by chance. The dominant annual grass, the most common shrub, and a perennial tussock-forming sedge all decrease with high levels of grazing. Most species exhibit an ephemeral life strategy in response to unreliable rainfall, and this boom and bust strategy effectively doubles as an adaptation to grazing. After 20 years of exposure to managed grazing with domestic stock in Australian dune swales, patterns in species richness have not emerged in response to grazing pressure, the ecosystem has not been transformed to another degradation "state," and there is no evidence that grazing relief refuges provide havens for species highly sensitive to grazing

Not All Kinds of Revegetation Are Created Equal: Revegetation Type Influences Bird Assemblages in Threatened Australian Woodland Ecosystems

The value for biodiversity of large intact areas of native vegetation is well established. The biodiversity value of regrowth vegetation is also increasingly recognised worldwide. However, there can be different kinds of revegetation that have different origins. Are there differences in the richness and composition of biotic communities in different kinds of revegetation? The answer remains unknown or poorly known in many ecosystems. We examined the conservation value of different kinds of revegetation through a comparative study of birds in 193 sites surveyed over ten years in four growth types located in semi-cleared agricultural areas of south-eastern Australia. These growth types were resprout regrowth, seedling regrowth, plantings, and old growth

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Aves, Booderee National Park, Jervis Bay territory, south-eastern Australia

A large-scale, long-term study is being conducted to describe the bird assemblages inhabiting a 6500 ha areaat Booderee National Park, south-eastern Australia. In this paper, we provide a list of birds recorded within rainforest,forest, woodland, shrubland, heathland and sedgeland during surveys conducted each spring between 2003 and 2007. Ofparticular interest was the contrast between the birds of sites burned in a wildfire in 2003 and sites that remainedunburned. We recorded a total of 103 species from 35 families. We found that after the major fire, the vast majority ofindividual species and the bird assemblage per se in most vegetation types recovered within two years. Exceptionsoccurred in structurally simple vegetation types such as sedgeland and wet heathland in which reduced levels of specieshad not returned to pre-fire (2003) levels by 2007

Average counts for growth types in a particular year and season.

<p>Average counts for growth types in a particular year and season.</p

Correspondence analysis biplots of bird species and growth type.

<p>The diagrams are: (left) first versus third dimensions from correspondence analysis and (right) second and third dimensions from correspondence analysis. Distances between species approximate the chi-squared distance between species distributions (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034527#pone.0034527-Lep1" target="_blank">[59]</a> for details of the approach used in data analyses).</p

The South-west Slopes study region of southern New South Wales, south-eastern Australia.

<p>The South-west Slopes study region of southern New South Wales, south-eastern Australia.</p

Biplot of the first two canonical axes showing species and growth types.

<p>Distances between species approximate the chi-squared distance between species distributions (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034527#pone.0034527-Lep1" target="_blank">[59]</a> for details of the approach used in data analyses).</p

Median values for vegetation characteristics in different growth types.

<p>Median values for vegetation characteristics in different growth types.</p