Slope–channel decoupling in Wolumla catchment,New South Wales,Australia: the changing nature of sediment sources following European settlement

Within a few decades of European settlement, channel incision transformed discontinuous river courses throughout Wolumla catchment, on the south coast of New South Wales, Australia. The development of continuous channels greatly increased sediment delivery from the catchment. This paper documents the character, timing and proportion of sediment sourced from upland valley fills, channel expansion sites, and gully networks. Volumes of material transferred from these sources are compared with estimates of sediment eroded from hillslopes, and the movement of sediment off the slopes to the valley floor is assessed. Although disturbance of slopes resulted in significant movement of materials, most of this material has been stored on-slope, in trapped tributary fills and along lower order drainage lines. The slopes are effectively decoupled from the channel. Sediment accumulation in farm dams over the past few decades has been negligible. Around 75% of the total volume of material released from creeks in Wolumla catchment since 1865, i.e., 5500×10³ m³, has been derived from channel incision into valley fills at the base of the escarpment. Sediment flushing occurred within a few decades of catchment disturbance. Bedrock confinement in the middle and lower catchment resulted in very efficient downstream transfer of materials. Although gully networks and channel expansion sites have released a relatively small volume of material, these sources are the greatest contemporary source of sediment in Wolumla catchment.     

What soil information do crop advisors use to develop nitrogen fertilizer recommendations for grain growers in New South Wales,Australia?

The Australian grains industry relies on mineralized nitrogen (N) from soil organic matter and plant residues, but fertilizer N is increasingly needed to optimize yields. Most farmers are guided on N fertilizer requirements by commercial crop advisors. We surveyed (n = 132) and interviewed (n = 11) New South Wales grains advisors to gauge the usage of soil process understanding, soil data and decision support systems (DSSs) when developing N recommendations. Soil moisture at sowing, seasonal forecasts, crop rotation, soil mineral N, financial risk profiles and paddock history were all used to prepare N fertilizer advice, but stored soil moisture was most important. Farmer confidence in soil N testing was low due to high spatial variability. Most advisors calculated N fertilizer required for yields within 10%–15% of crop potential, but clients’ attitude to financial risk guided final N recommendations. Conservative growers preferred a low input system, while more reliable rainfall or greater reliance on stored soil water led growers to apply higher N rates to maximize long‐term profits. Advisors preferred “rules‐of‐thumb,” simple DSSs and knowledge of crop growth, to elaborate DSSs requiring detailed inputs and soil characterization. Few used in‐crop N sensing. N decision methodologies need to be updated to account for changes in soil fertility, cropping systems and farming practices. New research is needed to answer practical questions regarding soil N mineralization and N losses associated with alternative N application practices and extreme weather events. Training of new advisors in N processes and DSS use needs to be ongoing.     

Hunting or habitat degradation? Decline of primate populations in Udzungwa Mountains,Tanzania: An analysis of threats

Hunting and habitat degradation are universal threats to primates across the tropics, thus deciphering the relative impact of threats on population relative abundance is critical to predicting extinction risk and providing conservation recommendations. We studied diurnal primates over a period of nearly 6 years in the Udzungwa Mountains of Tanzania, a site of global importance for primate conservation. We assessed how population relative abundance of five species (of which two are endemic and IUCN-Endangered) differed between two forest blocks that are similar in size and habitat types but contrast strongly in protection level, and how abundance changed during 2004–2009. We also measured habitat and disturbance parameters and, in the unprotected forest, evaluated hunting practices. We found significant differences in primates’ abundance between protected and unprotected forests, with the greater contrast being the lower abundance of colobine monkeys (Udzungwa red colobus and Angolan colobus) in the unprotected forest. At this site moreover, colobines declined to near-extinction over the study period. In contrast, two cercopithecines (Sanje mangabey and Sykes’ monkey) showed slightly higher abundance in the unprotected forest and did not decline significantly. We argue that escalating hunting in the unprotected forest has specifically impacted the canopy-dwelling colobus monkeys, although habitat degradation may also have reduced their abundance. In contrast, cercopithecines did not seem affected by the current hunting, and their greater ecological adaptability may explain the relatively higher abundance in the unprotected forest. We provide recommendations towards the long-term protection of the area.     

Is there an impact of climate change on soil carbon contents in England and Wales?

It is not yet clear how soils are responding to a warming climate. A major study using the National Soil Inventory (NSI) of England and Wales reported large declines in soil carbon concentration across 11 land uses between 1978 and 2003 and concluded there was a link to climate change. However, a second, almost contemporary study, recorded no significant changes, raising the possibility that the reported declines were caused by changes in land use and management rather than by climate change. We have used ‘space‐for‐time’ substitution on the data from the initial NSI study, combined with changes in rainfall and temperature over the survey period, to determine the extent to which the declines in soil carbon observed in the second NSI study could be predicted from changes in climate. For organo‐mineral and mineral soils, little (0–5%) of the observed decline in carbon concentration can be predicted from changes in climate. In contrast, 9–22% of the changes reported for organic soils in semi‐natural habitats are consistent with changes in temperature and rainfall between the two NSI surveys. We also found that carbon concentration in organic soils in semi‐natural habitats declines as temperatures exceed 7°C, mirroring independent observations for the decline in bog and dense shrub moor vegetation as temperatures rise above 7°C, and raising the possibility that climate change may influence soil carbon indirectly by changing vegetation cover, and hence litter quality.     

Fertilizer Amendment of Mining-Impacted Soils from Broken Hill, Australia: Fixation or Release of Contaminants?

The aim of the study was to appraise various types of phosphate fertilizers (bone meal, superphosphate, triple superphosphate, and potassium orthophosphate) for immobilizing metals and metalloids in mining-impacted soils from Broken Hill, Australia. Soils were rich in metals (Pb, Zn, Cu, and Cd) and metalloids (As and Sb) which were mainly contained in minor to trace amounts of coronadite [PbMn₈O₁₆], kintoreite [PbFe₃(PO₄)₂(OH,H₂O)₆], Pb, and Zn sulfides and sulfates (possibly sphalerite, galena, and anglesite) as well as in unidentified soluble metal-bearing phases. Phosphate stabilization experiments were conducted as kinetic column leaching experiments, and chemical and mineralogical changes were assessed using elemental, sulfur isotope, and XRD analyses as well as electron microprobe phase mapping. The application of phosphate fertilizer to the metal-contaminated topsoils led to mineralogical changes, including the formation of secondary metal-bearing phosphates. The elemental concentrations of leachates were used as a criterion to assess the performance of phosphate treatments. Potassium orthophosphate fertilizer was the most effective amendment for Cd stabilization; superphosphate and triple superphosphate fertilizers were the most effective amendments for Pb stabilization. By contrast, the release of As, Cu, Mn, Sb, and Zn were not significantly suppressed, and in several cases, increased, using bone meal, superphosphate, triple superphosphate, and potassium orthophosphate amendments. This study indicates that in situ phosphate stabilization of mining-impacted soils at Broken Hill would most likely be a complex and impractical undertaking in residential areas due to the risk of substantial metal, metalloid, phosphate, and sulfate release.     

Dynamics of the North–South Capital Flows or Rise of South–South Land Deals? Features of Land Acquisition in Ethiopia

Transnational land deals are among the most contested but inadequately understood topics. In this paper, we focus on the features of large‐scale transnational land deals (LSTLDs) in the Global South through an examination of Ethiopia. We apply a mixed method (qualitative and quantitative) research design.Results indicate that in 2005–2015, the government leased nearly 2·47 million ha of the country's approximate total 114 million ha area and offered 11·5 million ha of cultivable land to domestic and transnational investors. We explore the prevalence of LSTLDs deals by companies of the Global South, particularly entrepreneurs from India. Ethiopia's example validates emerging arguments on the rise of South–South investment deals rather than the established explanation of North–South capital flows. However, 75% of the land deals show poor performance. The study shows that LSTLDs have contributed to raising domestic agricultural production but have resulted in non‐performing loans of the banks of the host country. In sum, the land deals have resulted in financial grabbing, where Ethiopian banks end up with non‐performing loans and then must chase investors to settle the approximate €791 million in loans that investors borrowed for their projects. Copyright © 2017 John Wiley & Sons, Ltd.     

Effect of ammonium chloride,ammonium sulphate,and sodium nitrate on take‐all and grain yield of wheat grown on soils in South‐western Australia

Five field experiments are described which measured the effect of three sources of nitrogen (N) fertilizer, applied at 45 kg N/ha, on the incidence of take‐all and grain yield of wheat. The N fertilizers were ammonium sulphate, ammonium chloride, and sodium nitrate. Compared with the Nil N treatment, ammonium‐nitrogen fertilizer, either as ammonium sulphate (ASdr) or ammonium chloride (ACdr) drilled with the seed, lowered the severity of take‐all. Sodium nitrate topdressed (SNtd) to the soil surface reduced the severity of take‐all in three of five experiments, while ammonium sulphate topdressed (Astd) reduced the severity in four of the five experiments. Ammonium sulphate and ammonium chloride drilled with the seed were equally effective in reducing the severity of take‐all in three of the five experiments. However, ACdr was more effective than ASdr in reducing the severity of take‐all in one experiment whereas ASdr was more effective than ACdr in another experiment. In these two experiments (1 and 5), the effects of the reduction in take‐all severity between the ASdr and ACdr treatments did not affect grain yield. The results suggest that grain yield losses from take‐all are most severe where wheat plants are deficient in N. Chloride containing fertilizers are unlikely to control take‐all disease of wheat on soils of southwestern Australia.     

What's the Beef in South Korea Protests?: The Technical,Psychometric, and Sociocultural Dimensions of News Coverage of Risk

Millions of South Koreans took to the streets for more than 2 months in 2008 ostensibly in protest over their government's handling of beef imports from the United States. This study examines the technical, psychometric, and sociocultural dimensions of these public protests by conducting a content analysis of the coverage of the English language daily newspaper The Korea Herald. The results suggest that the scarcity of technical risk assessment information and the preponderance of normative or outrage factors in the newspaper's coverage (lack of trust in government, perceptions of inequity, and unequal benefits accruing to both nations) may have fueled public anxiety and anger. The findings also point to social, cultural, and historical factors that may explain why allowing U.S. beef into the Korean market elicited strong public reactions.     

Introduced house mice Mus musculus: a significant predator of threatened and endemic birds on Gough Island, South Atlantic Ocean?

House mice Mus musculus have successfully colonized many temperate and sub-Antarctic islands that are the location for breeding colonies of millions of seabirds. Unlike other introduced mammals, the impact of house mice on seabirds and endemic birds is believed to have been negligible. The breeding ecology of seabirds breeding on Gough Island, central South Atlantic Ocean, was studied for the first time during September 2000 to September 2001. Breeding success of the endangered Tristan albatross Diomedea (exulans) dabbenena and endangered Atlantic Petrel Pterodroma incerta were 27.3 and 19.9% respectively. Mortality of large Tristan albatross and Atlantic petrel chicks was observed, and the pattern of wounds and observations of feeding indicate that introduced mice were responsible for this predation. Breeding numbers of the endemic Gough bunting Rowettia goughensis are mostly found in upland areas of Gough Island where mice are scarce and are restricted to inaccessible cliffs in the lowlands where mice are abundant. This pattern, together with the high predation rates of artificial-eggs in lowland habitats in comparison to the uplands, strongly suggests that mice constrain the distribution of Gough buntings. The results of this study provide the first evidence for the role of house mice as a significant predator of endangered and endemic birds. Further research is required to determine if the observed levels of mice predation are a regular occurrence.     

The impact of taxonomic change on conservation: Does it kill, can it save, or is it just irrelevant?

The important question of taxonomy and its impact on conservation efforts was brought to general attention by Robert May in 1990 with a News and Views article in Nature entitled “Taxonomy as destiny.” Taxonomy, however, has built-in instabilities that result in name changes, raising the question of whether name changes have a consistent impact on conservation efforts. Our review investigates three possible outcomes of taxonomic change, namely a positive impact on protection efforts, a hampering impact, or no measurable impact. We address these cases with a review of the relevant literature: specifically, government and conservation agency reports, scientific papers, and the general press, as well as correspondence with biologists active in plant and animal conservation. We found no evidence of a consistent effect of taxonomic change on conservation, although splitting taxa may tend to increase protection, and name changes may have the least effect where they concern charismatic organisms.     

Will future climate change threaten a range restricted endemic species, the quokka (Setonix brachyurus), in south west Australia?

Range-restricted species, such as regional endemics, possess traits that may make them particularly vulnerable to environmental change. The quokka, Setonix brachyurus, is a small macropod, endemic to south-western Australia and two adjacent islands. Climatic factors appear to play a role in defining the distribution of this species. Mainland populations are historically restricted to areas with an annual average rainfall in excess of 700 mm and their current distribution is almost completely confined within the 1000 mm rainfall isohyet. As such, the predicted increasing aridity of south-western Australia due to climate change is likely to threaten the continued persistence of the quokka on the mainland. To examine this possibility, we modelled the distribution of the quokka with Maxent using records of occurrence and a combination of historical climate (1961-1990) and habitat variables. Future projections of this distribution were then examined assuming two simple dispersal scenarios (zero and full migration) and three climate-change scenarios of increasing severity for 2030, 2050 and 2070. The predictive performance of the distribution model generated under historical climate conditions was high (AUC > 0.8), with annual precipitation contributing the most information to the model. Except for the low-severity climate-change scenario under the full dispersal assumption, the future projected distribution of quokka was shown to contract over time. The extent of range contraction tended to increase with the severity of the climate-change scenario, with the species predicted to lose almost all range by the year 2070 under the most extreme climate-change scenario. The results indicate the importance of identifying potential refuges for the quokka (i.e. areas where the species is predicted to persist) and defining management strategies to protect these areas from threatening processes.     

‘Anti-erosion’ logs across paths in the southern uKhahlamba–Drakensberg Transfrontier Park,South Africa: Cure or curse?

Although path erosion is a widely studied topic, little is known about the potential environmental impact of ‘anti-erosion’ logs that are placed across paths to divert water. Results are reported of a project that assesses the placement of logs across paths in the uKhahlamba–Drakensberg Transfrontier Park, South Africa. The log spacing and dimensions are compared and correlated with path dimensions. Paths and diversion furrows adjoining the logs are examined for their sedimentology, structural strength and moisture retention. Although no strong correlations exist between log dimensions and path characteristics, thicker logs are better able to reduce the rate at which sediment overflows the logs. Results indicate high shear strength and penetrometer values for the path tread; however drainage furrows which divert flow off the paths have low soil strength values. Anti-erosion logs are in some instances responsible for downslope path deepening, whilst upslope sedimentation along the path tread may lead to vegetation succession. Although such processes may lead to multiple path development, the logs have a positive role in ensuring that sediment is re-positioned across the slope, thus reducing potential soil loss.     

Microbial Biomass,Carbon Stocks,and CO2 Emission in Soils of Franz Josef Land: High-Arctic Tundra or Polar Deserts?

Eurasian Soil Science - The biomass of prokaryotes and fungi, organic carbon stocks, and CO2 emission were studied in the Cryosols and Leptosols of Franz Josef Land. The highest carbon stocks were...     

Who eats four or more servings of fruit and vegetables per day? Multivariate classification tree analysis of data from the 1998 Survey of Lifestyle, Attitudes and Nutrition in the Republic of Ireland

OBJECTIVE: To identify, using the novel application of multivariate classification trees, the socio-economic, sociodemographic and health-related lifestyle behaviour profile of adults who comply with the recommended 4 or more servings per day of fruit and vegetables. DESIGN: Cross-sectional 1998 Survey of Lifestyle, Attitudes and Nutrition. SETTING: Community-dwelling adults aged 18 years and over on the Republic of Ireland electoral register. SUBJECTS: Six thousand five hundred and thirty-nine (response rate 62%) adults responded to a self-administered postal questionnaire, including a semi-quantitative food-frequency questionnaire. RESULTS: The most important determining factor of compliance with the fruit and vegetable dietary recommendations was gender. A complex constellation of sociodemographic and socio-economic factors emerged for males whereas the important predictors of 4 or more servings of fruit and vegetable consumption among females were strongly socio-economic in nature. A separate algorithm was run to investigate the importance of health-related lifestyle and other dietary factors on compliance with the fruit and vegetable recommendations. Following an initial split on compliance with dairy recommendations, a combination of non-dietary behaviours showed a consistent pattern of healthier options more likely to lead to compliance with fruit and vegetable recommendations. There did, however, appear to be a compensatory element between the variables, particularly around smoking, suggesting the non-existence of an exclusive lifestyle for health risk. CONCLUSIONS: Material and structural influences matter very much for females in respect to compliance with fruit and vegetable recommendations. For males, while these factors are important they appear to be mediated through other more socially contextual-type factors. Recognition of the role that each of these factors plays in influencing dietary habits of men and women has implications for the manner in which dietary strategies and policies are developed and implemented.     

Nest-mounds of the yellow meadow ant (Lasius flavus) at the “Alter Gleisberg”, Central Germany: Hot or cold spots in nutrient cycling?

Nests of the yellow meadow ant (Lasius flavus) occur at high densities in grasslands worldwide. Although many studies have shown that L. flavus nests influence soil nutrient contents, little is known about their effect on soil nutrient cycling rates. The aim of this study was to examine the role of nest-mounds inhabited by L. flavus as potential ‘hot spots’ for soil nutrient cycling. Six pairs of nest-mounds and control soils were selected at a grassland site at the plateau of the Alter Gleisberg (Thuringia, Central Germany). L. flavus significantly modified the soil environment within the nest. In comparison to the control soils, nest-mounds were characterized by slightly higher soil temperatures during the summer months. In addition, we found that nests were related to decreased potential C mineralization rates and increased potential net N mineralization rates. Nest-mound soil exhibited lower amounts of SOC, hot-water extractable DOC and DN, and higher concentrations of leachable DOC and DN. Moreover, ants promoted the enrichment of base cations in the nest. Differences in the soil environment between nests and control soils were possibly a result of the burrowing activity of ants, soil mixing, accumulation of aphid honeydew, and decreased plant-derived nutrient inputs into the nest-mound soil. In conclusion, L. flavus nest-mounds had a significant but element dependent effect on the soil nutrient cycling and may represent cold spots for C cycling and hot spots for N cycling. Thus, L. flavus nests increase the spatial heterogeneity of soil properties and create unique micro-sites within grassland ecosystems.     

Book reviews,Hunting the Wild Potato in the South American Andes: Memories of the British Empire Potato Collecting Expedition to South America 1938– 1939. J. [John ‘Jack’] G. [Gregory] Hawkes.Botanical and Experimental Garden,University of Nijmegen,The Netherlands 2004. 224 pp.ISBN 90-9018021-4.

Book Review

Book reviews, Hunting the Wild Potato in the South American Andes: Memories of the British Empire Potato Collecting Expedition to South America 1938– 1939. J. [John ‘Jack’] G. [Gregory] Hawkes.Botanical and Experimental Garden, University of Nijmegen, The Netherlands 2004. 224 pp.ISBN 90-9018021-4.