Climate change, local institutions and adaptation experience: the village tank farming community in the dry zone of Sri Lanka

Farmers are in a continuous process of, individually and as community groups, adjusting to the observed variability in climate parameters. Climate shocks are considered by farmers in their decision-making as factors affecting risk and uncertainty, and farmers make their choices so as to minimize such risks. The overall outcome of these individual and community efforts is known as ‘climate adaptation’, which itself is a continuous process. Farmers are traditionally supported by local institutions in this process, which are also currently in a state of transformation. This study examines the climate adaptation responses of the village tank farming community in the dry zone of Sri Lanka in the context of transforming socioeconomic conditions and with the objective of identifying policy implications for adaptation to global climate change. The study was conducted in six Divisional Secretariat areas in the Anuradhapura District of the North Central Province. Both, primary and secondary data was collected in the study. The major sources of primary data included a series of focus group discussions and key informant interviews conducted with village tank farmers and local officers. The findings reveal that there are two major forms of voluntary adaptation responses by farmers against climate shocks: 1) aligning of farming activities with the recognized seasonal pattern of rainfall; and 2) management of rain water harvested in commonly owned village tanks. Farmers’ adaptation responses have been facilitated by local institutions that helped to adopt joint adaptation responses. However, recent socioeconomic dynamics introduced by rapid population increase, spread of commercial opportunities and change in agricultural technology have drastically altered conditions in the village tanks in favor of developing a commercial farming system. As a result, local institutions that traditionally facilitated the climatic adaptation responses are also in a state of transition. Therefore, farmers face problems in adapting to the impending risks and uncertainties of global climate change. The paper emphasizes the need for appropriate policy measures to facilitate the adaptive capacity of farmers.Length: pp.147-156Climate changeAdaptationFarmersArid landsVillagesTanksCommon property

Bionomics of the alder sawfly, Fenusa dohrnii (Tischbein)

Imperial Users onl

Transport in Floquet-Bloch bands

We report Floquet band engineering of long-range transport and direct imaging of Floquet-Bloch bands in an amplitude-modulated optical lattice. In one variety of Floquet-Bloch band we observe tunable rapid long-range high-fidelity transport of a Bose condensate across thousands of lattice sites. Quenching into an opposite-parity Floquet-hybridized band allows Wannier-Stark localization to be controllably turned on and off using modulation. A central result of this work is the use of transport dynamics to demonstrate direct imaging of a Floquet-Bloch band structure. These results demonstrate that transport in dynamical Floquet-Bloch bands can be mapped to transport in quasi-static effective bands, opening a path to cold atom quantum emulation of ultrafast multi-band electronic dynamics.Comment: 5 pages, 4 figure

MODELLING AGRO·FORESTRY SYSTEMS FOR IMPROVED ECONOMIC PERFORMANCE: A COMPARATIVE ECONOMIC ANALYSIS

Despite promising ecological features of various agro-Iorestry systems, adoption or thesesystems by farmers is not always encouraging. This is not surprising. as fanners areoperating in a highly competitive commercial environment. where priority is given toeconomic goals rather than environmental goals. One solution is to develop AF modelswith species combinations that generate economic returns comparable to competingenterprises. simultaneously with environmental benefits.The main objective of the current study is to investigate species combinations withimproved economic performance. Here two AF practices in Sri Lanka, namely, coconutinter cropping and avenue cropping based on Gliricidia were considered. lnformationgathered both from primary and secondary sources were used in the study. A number ofpotential crops were categorized according to their income generating and resourceutilisation patterns. Among them, there are perennials, semi perennials as well as seasonalcrops. Two AF models were developed using Linear Programming technique. Modelsproposed jak, banana, pepper and coffee as the inter cropping combination which gives thehighest economic performance under coconut based systems. In case of avenue croppingwith Gliricidia, number of legumes and cereals along with banana was selected as theoptimum combination. The economic performance of the developed models were assessedby cost-benefit analysis and their implications on a selected set of economic parametershave been discussed.The whole exercise shows that, species combination of a system is an important aspectwhich determines the economic performance of the system. It further suggests that speciescombination can be manipulated to generate models with desired economic characteristics.Therefore, challenge ahead is to design models with species combinations that find ahalance between economic and environmental objectives.

Experimental Realization of a Relativistic Harmonic Oscillator

We report the experimental study of a harmonic oscillator in the relativistic regime. The oscillator is composed of Bose-condensed lithium atoms in the third band of an optical lattice, which have an energy-momentum relation nearly identical to that of a massive relativistic particle, with an effective mass reduced below the bare value and a greatly reduced effective speed of light. Imaging the shape of oscillator trajectories at velocities up to 98% of the effective speed of light reveals a crossover from sinusoidal to nearly photon-like propagation. The existence of a maximum velocity causes the measured period of oscillations to increase with energy; our measurements reveal beyond-leading-order contributions to this relativistic anharmonicity. We observe an intrinsic relativistic dephasing of oscillator ensembles, and a monopole oscillation with exactly the opposite phase of that predicted for non-relativistic harmonic motion. All observed dynamics are in quantitative agreement with longstanding but hitherto-untested relativistic predictions.Comment: 10 pages; 4 figure

Quantifying and Controlling Prethermal Nonergodicity in Interacting Floquet Matter

The use of periodic driving for synthesizing many-body quantum states depends crucially on the existence of a prethermal regime, which exhibits drive-tunable properties while forestalling the effects of heating. This dependence motivates the search for direct experimental probes of the underlying localized nonergodic nature of the wave function in this metastable regime. We report experiments on a many-body Floquet system consisting of atoms in an optical lattice subjected to ultrastrong sign-changing amplitude modulation. Using a double-quench protocol, we measure an inverse participation ratio quantifying the degree of prethermal localization as a function of tunable drive parameters and interactions. We obtain a complete prethermal map of the drive-dependent properties of Floquet matter spanning four square decades of parameter space. Following the full time evolution, we observe sequential formation of two prethermal plateaux, interaction-driven ergodicity, and strongly frequency-dependent dynamics of long-time thermalization. The quantitative characterization of the prethermal Floquet matter realized in these experiments, along with the demonstration of control of its properties by variation of drive parameters and interactions, opens a new frontier for probing far-from-equilibrium quantum statistical mechanics and new possibilities for dynamical quantum engineering