75 research outputs found
Modelling the impacts of nature-based solutions using land surface models - webinar
No full textThis webinar introduces land surface modelling methodologies and their applicability to nature-based solutions as linked to the TES NbS project (https://sites.google.com/view/tesnbsworkshop). The webinar includes an introduction from Dr Petra Holden, the PI of the TES NbS project, a presentation by Dr Toby Marthews, an environmental scientist at UKCEH, and Dr Assumpta Onyeagoziri, an ecological mathematician and postdoctoral fellow for TES NbS. The webinar is relevant to any researcher, policy maker or practitioner who is interested in the topic. No modelling knowledge or experience is required.</p
Development of a UK coupled regional environmental prediction system for simulating and understanding air-land-sea interactions at convective-scale resolutions
No full textMore accurate prediction and warning of natural hazards, such as of the impacts of severe weather mediated through various components of the environment, require a more integrated Earth System approach to forecasting. Regional coupled prediction systems, in which the known interactions and feedbacks between different physical and biogeochemical components of the environment across sky, sea and land can be simulated, offer a framework within which this capability can be developed. We report on the activities of the UK Environmental Prediction Prototype project, which has provided the first implementation of an atmosphere–land–ocean–wave modelling system focussed on the United Kingdom and surrounding seas at km-scale resolution. The UK coupled system incorporates models of the atmosphere (Met Office Unified Model, UM), land surface with river routing (JULES), shelf-sea ocean (NEMO) and ocean waves (WAVEWATCH III). These components are coupled, via OASIS3-MCT libraries, at unprecedentedly high resolution across the UK within a north-western European regional domain. Priorities are presented for future development of the UK Environmental Prediction framework and component systems
Modelling regeneration in tropical forests
No full textThe mechanisms through which tropical trees, and thereby tropical forest areas, regenerate themselves remain little understood. The area of greatest ignorance in the life cycle of tree species is the early pre-seedling stage and, therefore, a set of experiments to investigate this stage was undertaken. Firstly, a field experiment to measure the secondary dispersal dynamics of three pioneer tree species in the Barro Colorado Island (BCI) forest of Panamá was carried out. Seeds were sown out in the forest and later recovered by excavating the surface soil where they were sown. The results of this project gave an estimate of the displacement and burial percentages to be expected for a small clump of seeds dispersed onto the forest floor. An assessment was made of the relative importance of abiotic and biotic mechanisms of secondary dispersal. Secondly, a modelling and field experiment used a soil water and heat transport model to characterise and predict soil drying in forest gaps. A three scenario modification to the gap-understorey dichotomy was suggested by the field measurements and model results. Thirdly, a modelling project used s simulation of the ground-level radiation regime of a forest, based on data from BCI, to investigate the relationship between high light areas and the areas delimited as gaps according to four different definitions. In addition to proposing a new method of surveying large forest areas for gaps, this project produced a well-validated model of forest structure. Finally, the results and programme produced during these three projects were synthesised into a description of several forest simulation sub-models, and possible directions for further research were outlined that may combine these into a full simulation model for a tropical forest.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Progress towards the CBD protected area management effectiveness targets
No full textThe management effectiveness of protected areas is a critically important consideration for their conservation success. Over 40 different protected area management effectiveness (PAME) data collection tools have been developed to systematically assess protected area management effectiveness. Many of these assessments have recently been collated into the Global IUCN Protected Area Management Effectiveness (PAME) database. We use the PAME database together with and the World Database on Protected Areas (WDPA) to assess current progress towards the Convention on Biological Diversity’s (CBD) 2010 and 2015 targets for PAME, which call for at least 30 per cent and 60 per cent of the total area of protected areas to have been assessed in terms of management effectiveness, respectively. We show that globally 29 per cent of the area protected has been assessed and 23 per cent of countries have reached the 60 per cent target. In addition 46 per cent of countries have reached the 30 per cent target. However, analytical results show that there are biases in the type of protected area assessed; protected areas with larger areas, and protected areas designated as National Parks (IUCN category II) are much more likely to have conducted a PAME assessment. In addition there is a paucity of PAME assessments from Europe and North America, where assessments of protected area management may already be integrated into protected area planning and monitoring systems, creating a challenge for reporting to the CBD. We further discuss the potential and limitations of PAME assessments as tools for tracking and evaluating protected area management, and the need for further assessment tools to address the ‘equity’ elements of Target 11 of the CBD
Calculating downward longwave radiation under clear and cloudy conditions over a tropical lowland forest site: an evaluation of model schemes for hourly data
No full textWhen will rejection of parasite nestlings by hosts of nonevicting avian brood parasites be favored? A misimprinting-equilibrium model
No full textIt has been suggested that discrimination and rejection of the nestlings of avian brood parasites are most likely to evolve when the parasite nestling is raised alongside the host nestlings, for example, many cowbird-host systems. Under these circumstances, the benefits of discrimination are high because the host parents may save most of their brood. However, there is a general absence of nestling rejection behavior among hosts of nonevicting parasites. In a cost-benefit equilibrium model, based on the premise that host species learn to recognize their offspring through imprinting on first breeding, we show that nestling recognition can be adaptive for hosts of cowbirds, but only under strict conditions. Namely, when host nestling survival alongside the parasite is low, rates of parasitism are high and the average clutch size is large. All of these conditions are seldom simultaneously achieved in real systems. Most importantly, the parasite nestling, on average, does not sufficiently depress host nestling survival to outweigh the costs of nestling recognition and rejection errors. Thus, we argue that nestling acceptance behaviors by hosts of nonevicting brood parasites may be explained as an evolutionary equilibrium in which recognition costs act as a stabilizing selection pressure against rejection when most of the host's offspring survive parasitism. Copyright 2003.brood parasitism; cost-benefit equilibrium; cowbirds; nestling rejection; nonevicting parasites; probability tree model
When will rejection of parasite nestlings by hosts of nonevicting avian brood parasites be favored ? A misimprinting-equilibrium model
No full textNbS-TISE: nature-based solutions tool for assessing the full impact of soil erosion. NC-International integration project for theme 2: assessing net zero plus trade-offs
No full text•Soil erosion is one of the main drivers of land degradation, reducing the resilience of terrestrial ecosystems to future climate change and threatening food security worldwide. Sub-Saharan Africa (SSA) is one of the most adversely affected regions, with 60-80% of people working as smallholder farmers reliant on local agriculture for their livelihoods as well as their direct food supply. Nature-based Solutions (NbS) are often cited as important strategies to mitigate the impacts of global environmental change on land degradation and its impacts. However, their efficacy relies on building an accurate evidence base of likely co-benefits and trade-offs to environment and society (e.g. economic costs, food security and biodiversity conservation).
•For this pilot project, we developed a new tool called NbS-TISE (Nature-based Solutions Tool for assessing the full Impact of Soil Erosion). This new tool allows us to efficiently integrate processes of weather and climate, land use change and surface runoff to make robust estimates of soil erosion rates over space and time. The tool was developed through integration of work packages 1B and 2C in the NC-International programme under Theme 2 (assessing Net Zero Plus trade-offs), combining expertise on the JULES land surface model with experience applying the RUSLE soil erosion model in SSA.
•Soil erosion routines based on the RUSLE model were coded as a post-processing workflow based on outputs from the JULES model. Because JULES also has existing code structures that can predict the spatial occurrence of surface runoff, this makes it possible to simulate a wider set of erosional processes and sediment transport over the land surface. The model and workflow were then tested over two small catchment areas in South Africa’s Western and Eastern Cape regions where there is an extensive knowledge base of NbS from staff at the African Climate & Development Initiative (ACDI; University of Cape Town). In addition, the InVEST Sediment Delivery Ratio (SDR) model, which uses RUSLE, was used to simulate erosion in these same catchment areas to provide both a comparison against JULES simulation results and additional outputs including the role of land cover and management in inhibiting further erosion and sediment delivery to rivers.
•Patterns of soil erosion and sediment yield from existing third-party datasets indicate that soil erosion is generally most severe towards the Eastern Cape and steeper sloping areas in the Western Cape. Our modelling appears to reflect this, albeit, with some subtly different spatial patterns and higher predicted values compared to the South African national RUSLE map from 2008, which most likely stem from our simplified estimates of rainfall erosivity, land cover and management, and the lack of adequate consideration of agricultural and conservation practices in the region, due to a lack of spatially explicit data on these practices. SDR model results highlight that a large proportion of potential soil erosion (assuming a landscape completely bare of vegetation cover) is mitigated by existing land cover and management factors, which will be useful for informing future NbS strategies in the region. Results from the JULES model, conversely, draw attention to additional factors, such as the occurrence of runoff-based erosion in topographic valleys where rainfall is non-negligible.
•Through further development and application, the new NbS-TISE tool will be able to provide valuable decision-support information to directly inform on two aspects of Net-Zero-Plus: maintaining a healthy and productive environment and adapting and building resilience to a changing climate. We suggest several key areas to work with other work packages within NC-International and international partners to apply this tool elsewhere, including:
across a wider set of catchments in Sub-Saharan Africa, linking with ongoing work in East Africa (WP2C) as well as West Africa (WP3C);
within Malaysia and Indonesia (linking with WP2B) to assess the vulnerability of oil palm plantations to soil erosion and flash flooding, particularly the scale of the increased risk compared to naturally forested conditions.
•Furthermore, we would look to develop soil erosion capabilities that are more sophisticated than RUSLE alone and include runoff-based processes. This would allow us to address erosion following short, high magnitude weather events (e.g. floods and wildfires) as well as consider additional important processes including river channel changes and gullying. Potential future directions include:
integrating MUSLE (a version of RUSLE that uses daily surface runoff instead of long-term rainfall erosivity estimates);
integrating a wider ensemble of daily time-stepped erosion models to allow for more robust scenario modelling in future;
experimenting with channel erosion modelling routines that can capture processes like riverbank erosion and gullying
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