Biochar and fertiliser applications influence phosphorus fractionation and wheat yield

The use of biochar in agriculture to achieve the dual benefits of improving soil quality whilst sequestering carbon (C) has received much attention. However, in low-intensity broadacre agricultural systems where yield is constrained by rainfall and costs associated with phosphorus (P) fertiliser, the application of biochar at rates commonly reported (>10 t ha^?1) are likely to be prohibitively expensive where yield benefits cannot be guaranteed. In marginal areas where calcareous soils dominate, biochar application has no liming effect, reducing its value compared to application in acidic soils. In the present study, we use a field experiment to investigate the interaction between P fertilisation and biochar banding at low application rates (<1 t ha^?1) on wheat yield and soil P fractionation (assessed by a modified Hedley method) in a highly alkaline Haplic Calcisol in a dryland broadacre cropping system. Our results demonstrate no statistically significant effect of low rate biochar banding on wheat yield in this highly P-constrained soil, but a significant effect of both biochar and fertiliser on P fractionation in both years of the study. Higher P fertiliser rates significantly increased wheat yield in all biochar treatments. The interactions between biochar, P fertiliser and P fractionation indicate shifts in potential P availability both as a result of P fertilisation and also biochar application. Further work is required in low productivity calcareous systems such as that studied here to elucidate the potential for biochar amendment to improve productivity and sequester C.     

Bushmeat trade in the Cross–Sanaga rivers region: Evidence for the importance of protected areas

Exploitation of wildlife for meat in the tropics (‘bushmeat’) is a critical threat for biodiversity, particularly in Africa. Here, we investigate the importance of protected areas (National Parks and other forest parks) as sources for the trade by exploring patterns in pricing and condition of bushmeat carcasses. We surveyed carcass prices in a large sample of trading points (87 markets surveyed, over a 35,000 km² area) in Cameroon and Nigeria in the Cross–Sanaga region of West Africa. We assessed evidence for national parks as the source of animals traded as bushmeat. The study area included rural and urban centers (Calabar, Nigeria, and Douala, Cameroon) close to important protected areas: the Cross River National Park in Nigeria, and Korup National Park in Cameroon. Both parks host very high species diversity, including a range of endemics. Prices increased with distance from national park boundaries, particularly in Cameroon, where parks may be less depleted than in Nigeria. There was evidence that trading points closer to parks were more likely to function as wholesalers, with meat moving onto further trading points, rather than being sold to the end consumer. Carcasses were more often smoked (a treatment aimed at preservation) if they were not sold to their final consumers; smoking was also commoner at larger trading points. Prices were higher close to the road network, where opportunities for further trade were more available. We consider how wildlife harvests in and around protected areas may be managed to minimize depletion of animal populations, and if protected areas may, on the principle of marine no-take zones, be sustainable sources for regulated harvests.     

The effect of lysine‐supplemented wheat gluten‐based diet on yellow perch Perca flavescens (Mitchill) performance

Formulation of nutritionally complete and cost efficient diets for yellow perch (Perca flavescens) is a prerequisite for successful intensive culture of this species. One of the objectives of this study was to determine the optimum diet for the grow‐out phase of juvenile yellow perch. Fish at the size of 12.9 ± 4 g were individually marked with passive integrated transponders (PIT)‐tags and randomly distributed into six 400 L tanks, 45 fish per tank. This experiment included lysine‐deficient [(?) Lys] and lysine‐supplemented [(+) Lys] wheat‐gluten‐based diets in triplicate groups. Our experiment showed that the mean weight of fish fed (+) Lys diet (83.9 ± 1.5 g) was significantly larger than fish fed (?) Lys diet (68.6 ± 5.2 g) (P < 0.05). This experiment also showed that the blood plasma concentration of free lysine in (+) Lys group was significantly higher than in (?) Lys group (P < 0.05) and the same trend appeared also in methionine concentrations. The concentration of Lys in deficient group of fish, 3 h after a meal was lower compared with levels of Lys 24 h post‐feeding (P < 0.05). Lysine deficiency in diet resulted in significantly higher level of serine, and a similar trend occurred in small and large fish.     

Community, lions, livestock and money: A spatial and social analysis of attitudes to wildlife and the conservation value of tourism in a human–carnivore conflict in Botswana

We quantified livestock (cattle, shoats, horses and donkeys) losses to lions (Panthera leo) and attitudes to lions, livestock losses and tourism among livestock owners, village residents and tourism workers around Makgadikgadi Pans National Park in Botswana. Losses were not correlated with the size or structure of livestock enclosures, numbers of dogs or herders. Rather losses increased with the amount of livestock owned. Most were stray animals preyed upon at night. Attitudes to wildlife, conservation and lions were also not consistently distributed within the society we studied. Negative attitudes to lions were almost ubiquitous among cattleposts but less widespread among people living in the more urbanized society of villages or among people working in tourism.Although four tourist camps were operating in the area, benefits from these operations were largely limited to employees. Despite considerable sums of money being paid to Botswana by local tourist facilities few respondents viewed tourism as valuable and most felt that the government and not they or their community was the main beneficiary of tourism. Tourism employees made up a small sub-section of the adult population drawn predominately from larger villages while the costs of livestock losses were spread among cattleposts near the park boundary. These same cattlepost respondents were not prepared to improve stock care to protect livestock, but indicated a willingness to kill lions instead. If tourism is to play a role in reducing human–wildlife conflict, communities must not be regarded as homogenous entities into which to distribute benefits evenly. Benefits might usefully be distributed in relation to the costs of coexisting with wildlife or used as incentives to better protect livestock or other human resources.     

Current uptake of 15N-labeled ammonium and nitrate in flooded and non-flooded black spruce and tamarack seedlings

? We investigated the effects of flooding for three weeks on physiological responses and uptake of NH ₄ ⁺ and NO ₃ ^? by black spruce (Picea mariana (Mill.) BSP.) and tamarack (Larix laricina (Du Roi) K. Koch) seedlings fertilized with labeled (¹⁵NH₄)₂SO₄ or K¹⁵NO₃ in a growth chamber experiment.

? Flooding reduced photosynthesis (A), transpiration (E), water use efficiency (WUE), and current uptake of NH ₄ ⁺ and NO ₃ ^? in both species.

? Under flooding, there were no significant differences between the two species in uptake of either NH ₄ ⁺ or NO ₃ ^? at the whole-plant level but black spruce had higher translocation of NH ₄ ⁺ to the shoots than did tamarack.

? Under non-flooded conditions, black spruce seedlings exhibited higher uptake of both NH ₄ ⁺ and NO ₃ ^? than did tamarack and demonstrated preferential uptake of NH ₄ ⁺ (19. 7 mg g^?1dw) over NO ₃ ^? (12.3 mg g^?1dw after three weeks). In contrast, non-flooded tamarack seedlings had equal uptake of NH ₄ ⁺ (4.96 mg g^?1dw) and NO ₃ ^? (4.97 mg g^?1dw).

? We hypothesize that the ability of tamarack to equally exploit both ¹⁵NH ₄ ⁺ and ¹⁵NO ₃ ^? would confer an advantage over black spruce, when faced with limitations in the availability of different forms of soil nitrogen.

     

Shipboard geophysical indications of asymmetry and melt production beneath the east pacific rise near the MELT experiment

Near the Mantle Electromagnetic and Tomography (MELT) Experiment, seamounts form and off-axis lava flows occur in a zone that extends farther to the west of the East Pacific Rise than to the east, indicating a broad, asymmetric region of melt production. More seamounts, slower subsidence, and less dense mantle on the western flank suggest transport of hotter mantle toward the axis from the west. Variations in axial ridge shape, axial magma chamber continuity, off-axis volcanism, and apparent mantle density indicate that upwelling is probably faster and more melt is produced beneath 17 degrees15'S than beneath 15 degrees55'S. Recent volcanism occurs above mantle with the lowest seismic velocities.     

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.     

A lectin histochemical study on the testis of the babirusa, Babyroussa babyrussa (Suidae)

The distribution of lectin bindings in the testis of babirusa, Babyrousa babyrussa (Suidae) was studied histochemically using 10 biotinylated lectins, Peanut agglutinin (PNA), Ricinus communis agglutinin (RCA I), Dolichos biflorus agglutinin (DBA), Vicia villosa agglutinin (VVA), Soybean agglutinin (SBA), Wheat germ agglutinin (WGA), Lens culinaris agglutinin (LCA), Pisum sativum agglutinin (PSA), Concanavalin A(Con A) and Ulex europaeus agglutinin (UEA I). Nine of 10 lectins showed a variety of staining patterns in the seminiferous epithelium and interstitial cells. The acrosome of Golgi-, cap- and acrosome-phase spermatids displayed various PNA, RCA I, VVA, SBA and WGA bindings, indicating the presence of glycoconjugates with D-galactose, N-acetyl-D-galactosamine and N-acetyl-D-glucosamine sugar residues respectively. No affinity was detected in the acrosome of late spermatids. LCA, PSA and Con A which have affinity for D-mannose and D-glucose sugar residues were positive in the cytoplasm of spermatids and spermatocytes. DBA was positive only in spermatogonia. In addition to DBA, positive binding in spermatogonia was found for VVA, WGA and Con A, suggesting the distribution of glycoconjugates with N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, D-mannose and D-glucose sugar residues. Sertoli cells were stained intensely with RCA I, WGA and Con A. In Leydig cells, RCA I and Con A were strongly positive, while WGA, LCA and PSA reactions were weak to moderate. The present findings showed that the distribution pattern of lectin binding in the testis of babirusa is somewhat different from that of pig or other mammals reported previously.     

Multiple-scale prediction of forest loss risk across Borneo

Context

The forests of Borneo have among the highest biodiversity and also the highest forest loss rates on the planet.

Objectives

Our objectives were to: (1) compare multiple modelling approaches, (2) evaluate the utility of landscape composition and configuration as predictors, (3) assess the influence of the ratio of forest loss and persistence points in the training sample, (4) identify the multiple-scale drivers of recent forest loss and (5) predict future forest loss risk across Borneo.

Methods

We compared random forest machine learning and logistic regression in a multi-scale approach to model forest loss risk between 2000 and 2010 as a function of topographical variables and landscape structure, and applied the highest performing model to predict the spatial pattern of forest loss risk between 2010 and 2020. We utilized a naïve model as a null comparison and used the total operating characteristic AUC to assess model performance.

Results

Our analysis produced five main results. We found that: (1) random forest consistently outperformed logistic regression and the naïve model; (2) including landscape structure variables substantially improved predictions; (3) a ratio of occurrence to non-occurrence points in the training dataset that does not match the actual ratio in the landscape biases the predictions of both random forest and logistic regression; (4) forest loss risk differed between the three nations that comprise Borneo, with patterns in Kalimantan highly related to distance from the edge of the previous frontier of forest loss, while Malaysian Borneo showed a more diffuse pattern related to the structure of the landscape; (5) we predicted continuing very high rates of forest loss in the 2010–2020 period, and produced maps of the expected risk of forest loss across the full extent of Borneo.

Conclusions

These results confirm that multiple-scale modelling using landscape metrics as predictors in a random forest modelling framework is a powerful approach to landscape change modelling. There is immense immanent risk to Borneo’s forests, with clear spatial patterns of risk related to topography and landscape structure that differ between the three nations that comprise Borneo.