Energy, Resources and the Environment

Words on Wednesday: Do Himalayan treelines respond to recent climate change? An evaluation of sensitivity indicators

ERE Matters June 10, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

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Schickhoff, U., Bobrowski, M., Böhner, J., Bürzle, B., Chaudhary, R. P., Gerlitz, L., Heyken, H., Lange, J., Müller, M., Scholten, T., Schwab, N., and Wedegärtner, R., 2015. Do Himalayan treelines respond to recent climate change? An evaluation of sensitivity indicators, Earth Syst. Dynam., 6, 245-265.

Abstract:

Climate warming is expected to induce treelines to advance to higher elevations. Empirical studies in diverse mountain ranges, however, give evidence of both advancing alpine treelines and rather insignificant responses. The inconsistency of findings suggests distinct differences in the sensitivity of global treelines to recent climate change. It is still unclear where Himalayan treeline ecotones are located along the response gradient from rapid dynamics to apparently complete inertia. This paper reviews the current state of knowledge regarding sensitivity and response of Himalayan treelines to climate warming, based on extensive field observations, published results in the widely scattered literature, and novel data from ongoing research of the present authors.

Anthropogenic treeline in Manang, Nepal, showing an abrupt transition to alpine grazing lands (Schickhoff, 24 September 2013).

Several sensitivity indicators such as treeline type, treeline form, seed-based regeneration, and growth patterns are evaluated. Since most Himalayan treelines are anthropogenically depressed, observed advances are largely the result of land use change. Near-natural treelines are usually krummholz treelines, which are relatively unresponsive to climate change. Nevertheless, intense recruitment of treeline trees suggests a great potential for future treeline advance. Competitive abilities of seedlings within krummholz thickets and dwarf scrub heaths will be a major source of variation in treeline dynamics. Tree growth–climate relationships show mature treeline trees to be responsive to temperature change, in particular in winter and pre-monsoon seasons. High pre-monsoon temperature trends will most likely drive tree growth performance in the western and central Himalaya. Ecological niche modelling suggests that bioclimatic conditions for a range expansion of treeline trees will be created during coming decades.

Climatic treeline (3900–4000 m) on a north-facing slope in Rolwaling, Nepal (Schwab, 18 September 2014).

Words on Wednesday: Farmers’ perceptions of and adaptation strategies to climate change and their determinants: the case of Punjab province, Pakistan

ERE Matters June 3, 2015

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Abid, M., Scheffran, J., Schneider, U. A., and Ashfaq, M., 2015. Farmers’ perceptions of and adaptation strategies to climate change and their determinants: the case of Punjab province, Pakistan, Earth Syst. Dynam., 6, 225-243.

Abstract:

Climate change is a global environmental threat to all economic sectors, particularly the agricultural sector. Pakistan is one of the countries negatively affected by climate change due to its high exposure to extreme events and low adaptive capacity. In Pakistan, farmers are the primary stakeholders in agriculture and are more at risk due to climate vulnerability. Based on farm household data from 450 households collected from three districts in three agroecological zones in the Punjab province of Pakistan, this study examines how farmers perceive climate change and how they adapt their farming in response to perceived changes in climate. The results demonstrate that awareness of climate change is widespread throughout the area, and farm households make adjustments to adapt their agriculture in response to climatic change. Overall 58% of the farm households adapted their farming to climate change. Changing crop varieties, changing planting dates, planting of shade trees and changing fertilizers were the main adaptation methods implemented by farm households in the study area. The results from the binary logistic model reveal that education, farm experience, household size, land area, tenancy status, ownership of a tube well, access to market information, information on weather forecasting and agricultural extension services all influence farmers’ choices of adaptation measures. The results also indicate that adaptation to climate change is constrained by several factors such as lack of information, lack of money, resource constraints and shortage of irrigation water in the study area. Findings of the study suggest the need for greater investment in farmer education and improved institutional setup for climate change adaptation to improve farmers’ wellbeing.

Schematic framework of farmers’ adaptation process in Pakistan.

Words on Wednesday: Cobalt, chromium and nickel contents in soils and plants from a serpentinite quarry

ERE Matters May 27, 2015

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Lago-Vila, M., Arenas-Lago, D., Rodríguez-Seijo, A., Andrade Couce, M. L., and Vega, F. A., 2015. Cobalt, chromium and nickel contents in soils and plants from a serpentinite quarry, Solid Earth, 6, 323-335.

Abstract:

The former serpentinite quarry of Penas Albas (Moeche, Galicia, NW Spain) left behind a large amount of waste material scattered over the surrounding area, as well as tailing areas. In this area several soils were studied together with the vegetation growing spontaneously over them with the aim of identifying the bioavailability of heavy metals. The potential of spontaneous vegetation for phytoremediation and/or phytostabilization was evaluated. The pH of the soils ranges from neutral to basic, with very low organic matter and nitrogen contents. There are imbalances between exchangeable cations like potassium (K) and calcium (Ca), mainly due to high magnesium (Mg) content that can strongly limit plant production. Moreover, in all of the studied soils there are high levels of cobalt (Co), chromium (Cr) and nickel (Ni) (>70, >1300 and >1300 mg kg^-1, respectively). They exceed the intervention limits indicated by soil guideline values. Different soil extractions were performed in order to evaluate bioavailability. CaCl₂⋅0.01M is the most effective extraction reagent, although the reagent that best predicts plant availability is a mixture of low molecular weight organic acids. Festuca rubra, L. is the spontaneous plant growing in the soils that accumulates the highest amount of the metals, both in shoot and roots. Festuca also has the highest translocation factor values, although they are only >1 for Cr. The bioconcentration factor is >1 in all of the cases, except in the shoot of Juncus sp. for Co and Ni. The results indicate that Festuca is a phytostabilizer of Co and Ni and an accumulator of Cr, while Juncus sp. is suitable for phytostabilization.

Extraction efficiency. In each soil, bars with different letters
indicate significantly different EF values (p <0.05) for each
metal. Hanging bars are the standard deviation.

Words on Wednesday: Flow-through experiments on water–rock interactions in a sandstone caused by CO2 injection at pressures and temperatures mimicking reservoir conditions

ERE Matters May 20, 2015

Words on Wednesday aims at promoting interesting/fun/exciting publications on topics related to Energy, Resources and the Environment. If you would like to be featured on WoW, please send us a link of the paper, or your own post, at ERE.Matters@gmail.com.

This week, we would like to share with you the latest manuscript of Farhana Huq, who was our guest-blogger on Monday! 🙂

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Huq, F., S.B. Haderlein, O.A. Cirpka, M. Nowak, P. Blum, P. Grathwohl, 2015. Flow-through experiments on water–rock interactions in a sandstone caused by CO2 injection at pressures and temperatures mimicking reservoir conditions. Applied Geochemistry, v58, 136–146.

Highlights:

Altmark sandstone showed CO₂-induced fluid–rock interactions under in-situ conditions.
Dissolution of anhydrite and calcite cements was inferred from fluid analysis.
Sample permeability increased by a factor 2.

Abstract:

Flow-through experiments were performed in a newly designed experimental setup to study the water–rock interactions caused by CO₂ injection in sandstones obtained from the Altmark natural gas reservoir under the simulated reservoir conditions of 125°C and 50 bar CO₂ partial pressure. Two different sets of experiments were conducted using CO₂-saturated millipore water and CO₂-saturated brine (41.62 g L^-1 NaCl and 31.98 g L^-1 CaCl₂·2H₂O), mimicking the chemical composition of the reservoir formation water. The major components in the sandstone were quartz (clasts + cement), feldspars, clay minerals (illite and chlorite), and cements of carbonates and anhydrite. Fluid analysis suggested the predominant dissolution of anhydrite causing increased concentrations of calcium and sulfate at early time periods at non-equilibrium geochemical conditions. The Ca/SO₄ molar ratio (>1) indicated the concurrent dissolution of both calcite and anhydrite. Dissolution of feldspar and minor amounts of clay (chlorite) was also evident during the flow-through experiments. The permeability of the sample increased by a factor of two mostly due to the dissolution of rock cements during brine injection. Geochemical modeling suggests calcite dissolution as the major buffering process in the system. The results may in future studies be used for numerical simulations predicting CO₂ storage during injection in sandstone reservoirs.

Reaction vessel used in the CO2/brine/rock reaction experiments on the Altmark sandstone – courtesy Farhana Huq