Potential synergies between existing multilateral environmental agreements in the implementation of Land Use, Land Use Change and Forestry activities

There is potential for synergy between the global environmental conventions on climate change, biodiversity and desertification: changes in land management and land use undertaken to reduce net greenhouse gas emissions can simultaneously deliver positive outcomes for conservation of biodiversity, and mitigation of desertification and land degradation. However, while there can be complementarities between the three environmental goals, there are often tradeoffs. Thus, the challenge lies in developing land use policies that promote optimal environmental outcomes, and in implementing these locally to promote sustainable development. The paper considers synergies and tradeoffs in implementing land use measures to address the objectives of the three global environmental conventions, both from an environmental and economic perspective. The intention is to provide environmental scientists and policy makers with a broad overview of these considerations, and the benefits of addressing the conventions simultaneously.Climate change, LULUCF, Biodiversity, Desertification, Sustainable development.

Mobilizing Sustainable Bioenergy Supply Chains

Analysis of the five globally significant supply chains conducted by IEA Bioenergy inter-Task teams – boreal and temperate forests, agricultural crop residues, biogas, lignocellulosic crops, and cultivated grasslands and pastures in Brazil – has confirmed that feedstocks produced using logistically efficient production systems can be mobilized to make significant contributions to achieving global targets for bioenergy. However, the very significant challenges identified in this report indicate that changes by all key members of society in public and private institutions and along the whole length of supply chains from feedstock production to energy product consumption are required to mobilize adequate feedstock resources to make a sustainable and significant contribution to climate change mitigation and provide the social and economic services possible. Notably, this report reveals that all globally significant bioenergy development has been underpinned by political backing, which is necessary for passing legislation in the form of mandates, renewable energy portfolios, carbon trading schemes, and the like. The mobilization potential identified in this report will depend on even greater policy support than achieved to date internationally.JRC.F.8-Sustainable Transpor

D'Annunzio sulla scena lirica: libretto o "Poema"?

Australia Direct Action climate change policy relies on purchasing greenhouse gas abatement from projects undertaking approved abatement activities. Management of soil organic carbon (SOC) in agricultural soils is an approved activity, based on the expectation that land use change can deliver significant changes in SOC. However, there are concerns that climate, topography and soil texture will limit changes in SOC stocks. This work analyses data from 1482 sites surveyed across the major agricultural regions of Eastern Australia to determine the relative importance of land use vs. other drivers of SOC. Variation in land use explained only 1.4% of the total variation in SOC, with aridity and soil texture the main regulators of SOC stock under different land uses. Results suggest the greatest potential for increasing SOC stocks in Eastern Australian agricultural regions lies in converting from cropping to pasture on heavy textured soils in the humid regions

Meta-analysis quantifying the potential of dietary additives and rumen modifiers for methane mitigation in ruminant production systems

Increasingly countries are seeking to reduce emission of greenhouse gases from the agricultural industries, and livestock production in particular, as part of their climate change management. While many reviews update progress in mitigation research, a quantitative assessment of the efficacy and performance-consequences of nutritional strategies to mitigate enteric methane (CH4) emissions from ruminants has been lacking. A meta-analysis was conducted based on 108 refereed papers from recent animal studies (2000-2020) to report effects on CH4 production, CH4 yield and CH4 emission intensity from 8 dietary interventions. The interventions (oils, microalgae, nitrate, ionophores, protozoal control, phytochemicals, essential oils and 3-nitrooxypropanol). Of these, macroalgae and 3-nitrooxypropanol showed greatest efficacy in reducing CH4 yield (g CH4/kg of dry matter intake) at the doses trialled. The confidence intervals derived for the mitigation efficacies could be applied to estimate the potential to reduce national livestock emissions through the implementation of these dietary interventions

The Star Formation History and Dust Content in the Far Outer Disc of M31

We present a detailed analysis of two fields located 26 kpc (~5 scalelengths) from the centre of M31. One field samples the major axis populations--the Outer Disc field--while the other is offset by ~18' and samples the Warp in the stellar disc. The CMDs based on HST/ACS imaging reach old main-sequence turn-offs (~12.5 Gyr). We apply the CMD-fitting technique to the Warp field to reconstruct the star formation history (SFH). We find that after undergoing roughly constant SF until about 4.5 Gyr ago, there was a rapid decline in activity and then a ~1.5 Gyr lull, followed by a strong burst lasting 1.5 Gyr and responsible for 25% of the total stellar mass in this field. This burst appears to be accompanied by a decline in metallicity which could be a signature of the inflow of metal-poor gas. The onset of the burst (~3 Gyr ago) corresponds to the last close passage of M31 and M33 as predicted by detailed N-body modelling, and may have been triggered by this event. We reprocess the deep M33 outer disc field data of Barker et al. (2011) in order to compare consistently-derived SFHs. This reveals a similar duration burst that is exactly coeval with that seen in the M31 Warp field, lending further support to the interaction hypothesis. The complex SFHs and the smoothly-varying age-metallicity relations suggest that the stellar populations observed in the far outer discs of both galaxies have largely formed in situ rather than migrated from smaller galactocentric radii. The strong differential reddening affecting the CMD of the Outer Disc field prevents derivation of the SFH. Instead, we quantify this reddening and find that the fine-scale distribution of dust precisely follows that of the HI gas. This indicates that the outer HI disc of M31 contains a substantial amount of dust and therefore suggests significant metal enrichment in these parts, consistent with inferences from our CMD analysis.Comment: Abstract shortened. 17 pages, 12 figures (+ 6 pages & 5 figures in Appendix). MNRAS, in pres

Restoring Degraded Lands

Land degradation continues to be an enormous challenge to human societies, reducing food security, emitting greenhouse gases and aerosols, driving the loss of biodiversity, polluting water, and undermining a wide range of ecosystem services beyond food supply and water and climate regulation. Climate change will exacerbate several degradation processes. Investment in diverse restoration efforts, including sustainable agricultural and forest land management, as well as land set aside for conservation wherever possible, will generate co-benefits for climate change mitigation and adaptation and morebroadly for human and societal well-being and the economy. This review highlights the magnitude of the degradation problem and some of the key challenges for ecological restoration. There are biophysical as well as societal limits to restoration. Better integrating policies to jointly address poverty, land degradation, and greenhouse gas emissions and removals is fundamental to reducing many existing barriers and contributing to climate-resilient sustainable development.</p

Restoring Degraded Lands

Land degradation continues to be an enormous challenge to human societies, reducing food security, emitting greenhouse gases and aerosols, driving the loss of biodiversity, polluting water, and undermining a wide range of ecosystem services beyond food supply and water and climate regulation. Climate change will exacerbate several degradation processes. Investment in diverse restoration efforts, including sustainable agricultural and forest land management, as well as land set aside for conservation wherever possible, will generate co-benefits for climate change mitigation and adaptation and morebroadly for human and societal well-being and the economy. This review highlights the magnitude of the degradation problem and some of the key challenges for ecological restoration. There are biophysical as well as societal limits to restoration. Better integrating policies to jointly address poverty, land degradation, and greenhouse gas emissions and removals is fundamental to reducing many existing barriers and contributing to climate-resilient sustainable development

Anthropogenic influence on sediment transport in the Whittard Canyon, NE Atlantic

Unusual peaks in turbidity were detected in two branches of the Whittard Canyon in June 2013. Enhanced nepheloid layers (ENLs) were defined as layers with concentrations of suspended particulate matter exceeding those of nepheloid layers typically observed in a given region. Here, ENLs had peaks in turbidity and elevated suspended particulate matter concentrations exceeding ~1 mg L−1 with the largest ENLs measuring between ~2–8mg L−1. The ENLs measured ~100–260m in vertical height and were detected inwater depths of between 640 and 2880 m. Vessel Monitoring System data showed that high spatial and temporal activity of potential bottom trawling vessels coincided with the occurrence of the ENLs. Molar C/N ratios of the suspended organic material from the ENLs showed a high degree of degradation. Regular occurrences of such events are likely to have implications for increased sediment fluxes, burial of organic carbon and alteration of benthic and canyon ecosystems

Storage and stability of soil organic carbon down the profiles under native woodland, native pastures and cultivation

Soils are widely recognized as having potential to sequester significant amounts of carbon (C). There is much speculation that deeper soil layers can store significant amounts of C in a relatively stable form and that land use can influence soil organic carbon (SOC) stocks at depth. Our understanding of the potential for subsoils to store C in the long term is however limited here in Australia, as little work has been done to quantify C stocks, and the available studies on C dynamics have been mainly focused in surface soils (30 cm or less), and conducted from a narrow range of management options. The main aim of this research was to examine SOC stocks and stability down texturally contrasted soil layers (up to 0.80 m) under three major land uses, namely native woodland, native pastures and cultivation, in the Northern Tablelands of New South Wales, Australia. Specifically, this study examined the effects of land use on a) the quantity of total SOC stocks down the profiles; b) dissolved organic carbon (DOC) concentrations down the profiles; c) the amounts and composition of dissolved organic matter (DOM) extracted from different litter types; b) quantity and quality of SOC among soil particle size fractions; c) SOC mineralization dynamics including C pools and turnover kinetics; and d) C and nitrogen (N) mineralization dynamics of decomposing plant litter and interactions with initial biochemical composition of litter. Understanding C stocks and organic matter stability in soils taking into account deeper soil layers as affected by land use will identify the most effective land use for carbon sequestration and thereby inform land use decisions in the northern region of NSW Australia. Strong differences in SOC stocks between land uses were only apparent in the surface 20 cm, with native pastures and cultivation which were statistically similar to each other containing on average 9 and 11 t/ha less C than native woodland. Significantly larger SOC stocks in surface soils under native woodland may be partly attributed to more lignin-rich recalcitrant above ground litter inputs compared with the other two land uses. The combined subsoil (20 to 80 cm) layers contained 40 % of the total profile SOC stocks across all land uses, demonstrating that substantial amounts of SOC stocks reside in deeper layers and so the importance of preserving it. The relative proportion of aromatic C in dissolved organic matter (DOM) extracted from litter was highest under native woodland, followed by native pasture then cultivation indicating qualitative differences in DOM fractions which may in turn influence biodegradability of DOM among litter types. DOC represented between 0.01 and 0.1 % of total SOC down the soil profiles and across all land uses showing that the contribution of DOC to C stocks was relatively small. Native woodland soils were associated with consistently wider C:N ratios in the particulate organic matter (POM) fraction throughout the soil profile compared with native pastures and cultivation which differed between each other in the top 50 cm. The result indicated differences in the quality of organic matter inputs (litter) entering the POM fraction with native woodland soils associated with less easily decomposed inputs due to their inherent chemical composition. Consequently, native woodland showed the least decline in particulate organic carbon (POC) with soil depth compared with the other two land uses. The proportion of MOC to the total SOC increased with soil depth indicating that subsurface C was more protected than surface C probably due to mineral association with clayey subsoils. Compared with native pastures and cultivation which were largely similar, native woodland soils contained significantly larger amounts of MOC in all soil depths suggesting that C was more physically protected from microbial attack. SOC mineralization kinetics over 419 days was well described by decomposition of a single pool. Compared with native pastures and cultivation, native woodland had larger amounts of the active C pools in all soil depths which were mainly related to larger amounts of labile substrates mainly DOC and POC down the profiles. The decomposition rate of the active C pool, measured by laboratory incubations, was strongly dependent on soil depth with turnover of 66 and 47 days in surface and subsoils respectively. Shorter turnover of active C pool in subsoils compared with surface soils may be linked to destabilization of active C stores when environmental constraints on decomposition which might inhibit decomposition in the undisturbed profile are removed following incubation under similar conditions in the laboratory. Consequently, it is important that the current C stores remain undisturbed. For all litter types, the active C pool whose decay rate constants ranged from 0.072 d-1 to 0.805 d-1, initially constituted 80 % of the litter mass. The decomposition rate of the slow C pool in litter was strongly and negatively correlated with the initial lignin:N ratio of plant litter suggesting that the interaction between these two litter quality variables had important controls over litter decomposition. Compared with other litter types, above and below ground litter from native woodland had higher initial lignin:N ratio and were associated with more stable slow C pools with longer half lives of 109 and 446 days respectively. The above and below ground litter components had distinct N mineralization patterns during the early stages of incubation as influenced by the initial biochemical composition of plant litter namely C:N ratio, % lignin and % water soluble carbon (WSC). Our results suggest that the biochemically recalcitrant lignin influenced the susceptibility of substrates to microbial attack and thereafter a demand for N by microbial decomposers. However, the subsequent release of N from substrates depended on the C:N ratio. The results of this thesis are relevant to landholders, natural resource managers and policy makers as they inform that native woodland soil has an important role in storing a) larger SOC stocks in surface (20 cm) layers compared with native pastures and cultivation which were generally similar, b) relatively less decomposable C down the soil profiles as larger amounts of C are associated with the mineral fraction, and c) more slowly decomposing organic matter inputs which were characterized by relatively stable slow C pools in litter compared with native pastures and cultivation in the northern region of NSW Australia. Key future research areas arising from this thesis include to: a) investigate land use effects on total SOC stocks in soil profiles using increased intensity of soil sampling in order to represent spatial variation and increase capacity to detect differences in total SOC especially where differences in C might be small such as in non-wooded land uses, b) compare land use effect on DOC storage at various depths during crop/pasture growing season as the living plant biomass may influence DOC concentrations, c) determine the stability of DOC derived from both soils and litter in order to determine its long term dynamics in soils, d) determine the long term stability of soil slow C pool and investigate the mechanisms by which C might be stabilized including the contribution of char C at various depths under the three land uses, e) determine the mechanism by which lignin and N interact to influence decomposability of litter, and f) understand the mechanism of SOC and N stabilization