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Coastal wetlands are carbon and nutrient sinks that capture large amounts of atmospheric C[O.sub.2] and runoff of nutrients. 'Blue carbon' refers to carbon stored within resident vegetation (e.g. mangroves, tidal marshes and seagrasses) and soil of coastal wetlands. This study aimed to quantify the impact of vegetation type on soil carbon stocks (organic and inorganic) and nitrogen in the surface soils (0-10 cm) of mangroves and tidal marsh habitats within nine temperate coastal blue carbon wetlands in South Australia. Results showed differences in surface soil organic carbon stocks (18.4 Mg OC [ha.sup.-1] for mangroves; 17.6 Mg OC [ha.sup.-1] for tidal marshes), inorganic carbon (31.9 Mg IC [ha.sup.-1] for mangroves; 35.1 Mg IC [ha.sup.-1] for tidal marshes), and total nitrogen (1.8 Mg TN [ha.sup.-1] for both) were not consistently driven by vegetation type. However, mangrove soils at two sites (Clinton and Port Augusta) and tidal marsh soils at one site (Torrens Island) had larger soil organic carbon (SOC) stocks. These results highlighted site-specific differences in blue carbon stocks between the vegetation types and spatial variability within sites. Further, differences in spatial distribution of SOC within sites corresponded with variations in soil bulk density (BD). Results highlighted a link between SOC and BD in blue carbon soils. Understanding the drivers of carbon and nitrogen storage across different blue carbon environments and capturing its spatial variability will help improve predictions of the contribution these ecosystems to climate change mitigation. Keywords: blue carbon, coastal wetlands, mangroves, soil carbon, soil nitrogen, temperate wetlands, tidal marshes., Introduction Occurring at the interface between land and sea, vegetated coastal wetlands are dynamic ecosystems that play an important role in global carbon and nutrient cycles (Duarte et al. 2013). [...]

Soil organic matter (SOM) is quantitatively a minor component (by mass and volume) of most soils, yet it is responsible for facilitating or moderating many key soil ecosystem services that [...]

Cassava (Manihot esculenta Crantz) is the staple food source for over 850 million people worldwide. Cassava contains cyanogenic glucosides and can be toxic to humans, causing paralysing diseases such as konzo, and even death if not properly processed. Konzo epidemics are often associated with times of drought. This may be due to a greater reliance on cassava as it is drought tolerant, but it may also be due to an increase in cyanogenic glucosides. Episodic droughts are forecast to become more common in many cassava-growing regions. We therefore sought to quantify the effect of water-stress on both yield and cyanogenic glucoside concentration (CNc) in the developing tubers of cassava. Five-month-old plants were grown in a glasshouse and either well watered or droughted for 28 days. A subset of droughted plants was re-watered half way through the experiment. Droughted plants had 45% fewer leaves and lower tuber yield, by 83%, compared with well-watered plants. CNc was 2.9-fold higher in the young leaves of droughted plants, whereas CNc in tubers from droughted plants was 4-fold greater than in tubers from well-watered plants. Re-watered plants had a similar biomass to control plants, and lower CNc than droughted plants. These findings highlight the important link between food quality and episodic drought. Cassava is a staple for over 850 million people, but it is toxic unless properly processed. A monotonous cassava diet often coincides with outbreaks of diseases such as konzo, especially during droughts. The concentration of cyanogenic glucosides in young tubers was 4-fold higher when plants were water stressed, but was lower following re-watering. We conclude that any expansion of cassava into new areas must be accompanied by knowledge of appropriate methods for detoxification, especially in areas increasing in aridity due to climate change. [ABSTRACT FROM AUTHOR]