31 research outputs found
From poison to food: On the molecular identity and indigenous peoples’ utilisation of poisonous “Lab-o” (Wild Yam, Dioscoreaceae) in Bukidnon, Philippines.
Establishment of background water quality conditions in the Great Zab River catchment:influence of geogenic and anthropogenic controls on developing a baseline for water assessment and resource management
The Great Zab River catchment is a major left-bank tributary of the River Tigris and drains a substantial part of the Kurdistan Region, an autonomous region of Northern Iraq. Within Kurdistan, the water resources of the Great Zab River catchment are under pressure from population increase and are utilized for potable, domestic and agricultural and industrial supply. As with many parts of the world, effective management of water resources within Kurdistan is hindered by a lack of water quality data and established background concentrations. This study therefore represents the first regional survey of river water chemistry for the Great Zab River catchment and presents data on the spatial and temporal trends in concentrations of As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Sr, Zn, NO3?, SO42?, F?, Cl? and PO43?, in addition to pH, electrical conductivity, dissolved oxygen and turbidity. As a tool for underpinning the management and monitoring of water quality, background concentrations were defined for the Great Zab catchment using three methods. The influences of geogenic and anthropogenic controls upon spatial and temporal trends in water chemistry are also evaluated. The influence of geogenic loading from underlying bedrock was identifiable within the observed spatial trends, with the most notable differences found between waters sampled from the relatively more volcanic-rich Zagros zone to the north and those sampled from the lower catchment underlain by younger clay-, sand- and siltstones. The greatest anthropogenic influence, identifiable through elements such as Cl? and NO3?, is present in the more highly populated lower catchment. The background concentrations identified in the Great Zab catchment would be those expected as a result of geogenic loading with some anthropogenic influence and represent a more conservative value when compared to those such as the World Health Organization Maximum Admissible Concentration. However, background concentrations represent a powerful tool for identifying potential anthropogenic impacts on water quality and informing management of such occurrencespublishersversionPeer reviewe
Social capital, social inclusion and changing school contexts: a Scottish perspective
This paper synthesises a collaborative review of social capital theory, with particular regard for its relevance to the changing educational landscape within Scotland. The review considers the common and distinctive elements of social capital, developed by the founding fathers – Putnam, Bourdieu and Coleman – and explores how these might help to understand the changing contexts and pursue opportunities for growth
The need to research refractory breathlessness
High-quality research is needed to improve quality of life for people with chronic refractory breathlessness in COP
Plant diversity patterns in neotropical dry forests and their conservation implications
This is the author accepted manuscript. The final version is available from American Association for the Advancement of Science via the DOI in this record.Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests. Our results provide a scientific framework within which national decision-makers can contextualize the floristic significance of their dry forest at a regional and continental scale.This paper is the result of the Latin American and Caribbean Seasonally Dry Tropical Forest Floristic Network (DRYFLOR), which has been supported at the Royal Botanic Garden Edinburgh by a Leverhulme Trust International Network Grant (IN-074). This work was also supported by the U.K. Natural Environment Research Council grant NE/I028122/1; Colciencias Ph.D. scholarship 529; Synthesys Programme GBTAF-2824; the NSF (NSF 1118340 and 1118369); the Instituto Humboldt (IAvH)–Red colombiana de investigación y monitoreo en bosque seco; the Inter-American Institute for Global Change Research (IAI; Tropi-Dry, CRN2-021, funded by NSF GEO 0452325); Universidad Nacional de Rosario (UNR); and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). The data reported in this paper are available at www.dryflor.info. R.T.P. conceived the study. M.P., A.O.-F., K.B.-R., R.T.P., and J.W. designed the DRYFLOR database system. K.B.-R. and K.G.D. carried out most analyses. K.B.-R. R.T.P., and K.G.D. wrote the manuscript with substantial input from A.D.-S., R.L.-P., A.O.-F., D.P., C.Q., and R.R. All the authors contributed data, discussed further analyses, and commented on various versions of the manuscript. K.B.-R. thanks G. Galeano who introduced her to dry forest research. We thank J. L. Marcelo, I. Huamantupa, C. Reynel, S. Palacios, and A. Daza for help with fieldwork and data entry in Peru
Seedling dynamics after different intensities of human disturbance in a tropical dry limestone forest in Jamaica
People’s local knowledge of climate change in the Middle-Hills of Nepal
585-595In the Pokhare Khola watershed of Dhading district in
the Middle-Hills of Nepal,
almost all farmers perceived that summers are becoming hotter and longer while
81% of interviewed farmers responded that winters are becoming warmer and
shorter. During the period of 1978 - 2008, the overall temperature has risen
about 0.20C. Summer temperatures have fluctuated, but mean winter
temperature has generally increased over this time. Meteorological data
corroborates the farmers’ perceptions. Annual and monsoon season rainfall was
highly variable over the last 30 years, with the lowest mean monsoon rainfall
(212 mm) in 1990 and the highest (646 mm) in 1999. Farmers observed that
duration of the rainy season has decreased from four to two months. The
reduction in wheat (Triticum aestivum L.) production due to shorter
winters and insufficient post-monsoon rain was evident. Changes in annual
rainfall pattern and resulting water shortages also lowered the millet [Eleusine<span style="font-size:11.0pt;color:windowtext;
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none;text-underline:none">(L.) Gaertn.] production. The
appearance of advancing phenological development in trees (flowering 10 - 25
days earlier), and earlier ripening of some crops were often cited as impacts
of change in climate. Household survey and interview, group discussions,
participatory rural appraisal (PRA) tools, viz. trend analysis, and problem
ranking were conducted to gather the observations and experiences on climate change
perceived by local people. Moreover, local meteorological data was analyzed to
see the trend of changes in rainfall and temperature.
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Identifying drivers of species compositional change in a semi-natural upland grassland over a 40-year period
Question: Few long-term studies exist with integrated vegetation and soil omposition data, coupled with detailed environmental driver records. Can hanges in community composition in an upland grassland be identified by evisitation after a 40-year period and allow the main environmental drivers of hange to be identified?
Location: Snowdon, Wales, UK.
Methods: Changes in plant community and soil composition were assessed by esurveying an upland Agrostis–Festuca grassland in 2008, 40 years after the oiginal survey. PCA and ecological indicators were used to determine changes i plant community composition. Redundancy analysis (RDA) allowed the mpact of soil chemical composition on the vegetation community to be assessed.
Results: A significant shift in community composition was found between ears. A 35% reduction in species richness and an increase in the grass:forb ratio, suggest significant ecosystem degradation. Indicator values suggest acidification of the community with an increased acidity preference of species recorded in 2008. However, soil pH measurements showed that soil pH had increased. RDA suggested that the main shifts in species composition were
correlated with an increase in pH and a reduction in soil exchangeable base cation concentration. Clear ecosystem responses to climate, land-use change or nitrogen enrichment were not observed.
Conclusions: Shifts in vegetation and soil composition are clearly identifiable after 40 years. The shifts in community composition are consistent with ecosystem degradation due to acidification during the period between surveys. Ecological indicator values and soil chemical composition displayed differing degrees of change. Whilst soils appear to be recovering from historic effects of
sulphur deposition, vegetation community composition changes appear to lag behind those in soil chemistry
Increased inorganic nitrogen leaching from a mountain grassland ecosystem following grazing removal:A hangover of past intensive land-use?
Heathlands and grasslands occur in montane regions, naturally or due to anthropogenic land-use. These are typically nutrient-poor but exposure to elevated nitrogen deposition and intensive livestock grazing causes large-scale ecological change. We studied the long-term implications of grazing removal on soil and drainage water biogeochemistry and the implications for nitrogen cycling in fifty-year replicated grazing exclosures on a montane grassland exposed to high rates of ambient nitrogen deposition. Evidence of ‘ecosystem recovery’ represented by successional change from graminoid to shrub-dominance after cessation of grazing was not reflected in the soil biogeochemistry. Cessation of grazing had a negative impact, with increased soil extractable and soil solution nitrate concentrations; an apparent shift towards a more nitrogen-rich, bacterially dominated microbial community; and the acidification of soils and leachate. The increase in nitrate leaching appears to have been counterbalanced by a decrease in dissolved organic nitrogen leaching, approximately maintaining the overall nitrogen balance of the system, whilst apparently altering ecosystem functioning. High rates of organic matter cycling and inorganic nitrogen uptake in grazed grassland may have sustained ecosystem N limitation under elevated nitrogen deposition. Grazing removal caused long-term over-supply of nitrogen from mineralisation of enriched organic matter, exacerbated by continued high nitrogen deposition, exceeding the uptake demand of heath vegetation and resulting in nitrification and nitrate leaching. This disequilibrium between vegetation and soil following grazing removal has implications for restoration after periods of intensive grazing. Grazing may not simply leave a legacy of nutrient enrichment but its cessation may trigger nitrogen saturation and soil and freshwater eutrophication and acidification which counteract the immediate benefits of natural vegetation recovery. Long term, nitrogen saturation of abandoned grasslands is likely to reduce ecosystem resilience to invasion by nitrophilous species, pathogen attack and vulnerability to environmental pressures such as climate change. We conclude that partial and/or phased reduction in grazing levels may permit the more synchronised recovery of soils and vegetation, thereby avoiding imbalances between nitrogen supply and nitrogen demand and detrimental ecological effects
Resilience of upland soils to long term environmental changes
The effect of long-term changes in land-use, pollution deposition and climate change on upland soils was evaluated
by resurveying a large set of sites in a mountain landscape in the UK, which were initially sampled forty
years ago. Unexpectedly, despite the length of time between sampling dates, no significant changes in pH, soil
exchangeable base cations or C and N percentage content by weight were observed across a range of soil type
and parent material. This suggests that the soils have been relatively resistant to the large changes in the environmental pressures experienced in the past forty years, which include a 1.5 °C increase in mean temperature;
the peak of UK sulphur deposition in around 1970, followed by ~90% deposition reduction; long-term increases
in nitrogen deposition; and major changes in grazing intensity. These results suggest that upland soils may be
considerably more resilient to the future environmental changes than many previous assessments have suggested