Models for predicting fire ignition probability in graminoids from boreo-temperate moorland ecosystems

An increase in both the frequency and severity of wildfires in boreo–temperate ecosystems is predicted. Therefore, to develop efficient fire rating systems, the relationship between the fuel moisture content (FMC) of vegetation and ignition thresholds needs to be determined. We developed fire ignition probability models for three graminoid species collected in central England, but common in boreo–temperate ecosystems (Eriophorum angustifolium, E. vaginatum and Molinia caerulea). Specifically, we assessed through laboratory experiments (1) seasonal differences between early spring and late summer in fuel traits such as height, fuel load, fuel bulk density and dead fuel load proportion, and (2) the role of these fuel traits, environmental conditions and dead FMC in determining the probability of ignition. There were seasonal differences in fuel traits among species, with an increase in dead fuel load proportion after winter. The dead FMC was the only variable determining initial sustained ignitions. However, the seasonal differences in dead fuel were not sufficient to affect the FMC threshold at which graminoids start to ignite. Graminoids begin to ignite at high levels of dead FMC, and there are differences between species (from 36.1% to 48.1%). This work assists in improving fire ignition predictions in graminoid-dominated ecosystems by providing warnings based on critical moisture thresholds.</jats:p

Tree – ring growth response of scots pine (Pinus Sylvestris l.) to climate change / Nur Idzhainee Hashim, Rob Marrs and Nor Hanisah Mohd Hashim

Dendrochronology is the scientific discipline of determining the relationship between tree growth and climate , and is determined using the annual growth rings. This provides a potential method for monitoring climate change. Climate usually acts as a major factor influencing the tree growth. Here, the effects of climate of a conifer species was assessed in relation to measured climatic variables. Tree cores of Scots Pine (Pinus sylvestris) w ere sampled from a forestry plantation at Hordron Edge, Derbyshire to determine the relationship between ann ual growth incremen t and four climate variables (maximum temperature, minimum temperature, grass minim um temperature and rainfall). Standard dendrochronological techniques were used to collect, prepare and measure tree–ring width increments . Climate data were derived from the British Atmospheric Data Centre (BADC) from 1921–2013. Tree-ring widths were as cross referenced to the climate data to enable growth dynamics of (Pinus sylvestris) to be investigated. In this study there was no significan t correlation between growth and climatic variables; overall average mean sensitivity ( m s ) was 0.28 mm, only five of the 20 trees were sensitive to climate ( m s >0.3) with the other 15 trees being complacen t ( m s <0.3). The growth incremen t index p ortra yed a cyclic pattern of tree growth through time with peaks (fast growth) and troughs (slow growth) throughout the period. There were no significan t first-order relationships found between tree growth indices and any of the four climatic variables tested. This result suggests that cl ima t ic variables were not significan t in controlling tree growth at this site

Effects of long-term removal of sheep grazing on the seedbanks of high-level grasslands and blanket bogs

Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested

Modelling Carbon Emissions in Calluna vulgaris-Dominated Ecosystems when Prescribed Burning and Wildfires Interact

A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions.This project was supported financially by the BiodivERsA FIREMAN program (NERC/Defra: NE/G002096/1), the Ecological Continuity Trust and the Heather Trust. VMS was supported by ªBeatriu de PinoÂsº fellowship (2014BP-B 00056) from the Generalitat de Catalunya. JGA was supported by Juan de la Cierva-fellowship (IJCI- 2014-21393)

From zero to 60: Building belief, capacity and community in Street Law instructors in one weekend

Street Law, where law students or lawyers teach about the law in local school, correctional, and community settings, is the fastest growing and most popular type of experiential legal education in the world—and with good reason. The Street Law methodology helps make the law more relevant, more accessible, and more understandable to both participants in the program and lawyers and law students delivering the programming. Despite Street Law’s prevalence and popularity, there is scant guidance for how to best introduce and implement a program, little research support explaining why Street Law works, and even less empirical justification proving that the program works. This paper makes three significant and unique contributions to the emerging field of Street Law scholarship and research. First, we provide an in-depth explanation of the principles and learner-centered practices that make Street Law such a powerful tool for legal education. Second, we ground these principles and practices in a robust body of research, the first such effort in the field. Third, we offer an annotated step-by-step outline of a unique weekend orientation program developed and field-tested by the seminal Georgetown Street Law program and delivered in partnership with the Law Societies of Ireland and Scotland. It is our hope that this paper will offer practitioners both a series of best practices to draw upon and a reason to do so. A second paper, that will shortly follow this one, will share and discuss quantitative and qualitative data evidencing the powerful outcomes that this weekend orientation can effect in participants