This paper examines the development and effects of a rapid livelihood transition on households, and reflects on how it fits within historic trends of livelihood change for people living in highly variable and vulnerable environments. It also discusses the implications of livelihood dynamism for local governance of natural resources. In recent decades, seaweed cultivation has expanded exponentially in coastal communities across the Asia-Pacific. A case study is presented of a remote small-island community in eastern Indonesia where over the last ten years a dramatic shift in livelihood focus has occurred. Previous dependence on diverse low-productivity livelihood activities transitioned to a predominant focus on seaweed farming. The case shows how social, economic and cultural environments co-develop as people move out of conditions of collective poverty and into more nuclear household-oriented livelihood activities. Specific attention is given to the influence on a marine resource co-management program operating on the island to illustrate how local livelihood dynamics relate to broader paradigm-driven conservation and rural development initiatives. While alternative livelihood programs seek to relieve pressure on resource stocks and provide opportunities for coastal people, this case study provides timely insights into the kinds of unintended effects, trends and impacts that are associated with rapid change in the way people make a living. This study argues that, in addition to achieving higher standards of income and well-being, livelihood improvement interventions need to adequately ensure that conditions under which new livelihood arrangements come to function can be maintained locally. 相似文献
The temperature induced structural evolution and thermoelastic behaviour of a natural (Pbca) orthopyroxene (Opx), with chemical formula M2(Mg0.856Ca0.025Fe2+0.119) M1(Mg0.957Fe2+0.011Fe3+0.016Cr0.011Al0.005)Al0.032Si1.968O6, from a suite of high pressure ultramafic nodules of mantle origin, have been investigated by in-situ neutron powder diffraction
at several temperatures starting from 1,200°C down to 150°C. Unit-cell parameter variations as a function of T show no phase transition within this temperature range. The volume thermal expansion coefficient, α = V−1(∂V/∂T) P0, varies linearly with T. The axial thermal expansion coefficients, αj = lj−1(∂lj/∂T)P0, increase non-linearly with T. The principal Lagrangian unit-strain coefficients (ɛ//a, ɛ//b, ɛ//c), increase continuously with T. However, the orientation of the unit-strain ellipsoid appears to change with T. With decreasing T, the values of the unit-strain coefficients along the b and c axes tend to converge. The orientation at ΔT = 1,080°C is maintained down to the lowest temperature (150°C). The two non-equivalent tetrahedral chains, TAnOA3n and TBnOB3n, are kinked differently. At room-T, the TBnOB3n chain is more strongly kinked by about 23° than the TAnOA3n chain. With increasing T, the difference decreases by 3° for the TBnOB3n chain. The intersite cation exchange reaction between M1 and M2 (Mg2+ and Fe2+) shows a slight residual order at 1,200°C followed by reordering with decreasing temperature although seemingly not with
a definite progressive trend. At the lowest temperature reached (150°C), reordering has occurred with the same value of partitioning
coefficient KD as that before heating. The absence of the expected phase transition is most likely due to the presence of minor amounts
of Fe3+, Al, Ca and Cr which must play a crucial role on the thermoelastic behaviour and phase stability fields in natural Opx, with
consequent important petrologic and geological implications. 相似文献
Understanding the linkages between social and ecological systems is key to developing sustainable natural resource management (NRM) institutions. Frequently, however, insufficient attention is paid to the historical development of NRM institutions. Instead, discussion largely focuses on models of economic efficiency at the expense of the cultural, historical, and ecological contexts within which institutions develop. Here we use the research program of historical ecology to explore the development, maintenance, and change of two contemporary fire management institutions in northern Australia and Colorado, USA, to demonstrate how social institutions and ecological systems change and resist change over time and how institutions interact across scales to negotiate contrasting goals and motivations. We argue that these NRM institutions are not strictly speaking evolutionary or adaptive, and that historical context is critical when evaluating how and why particular institutions and institutional relationships develop. As with ecosystems, the present characteristics of the NRM institutions are dependent on what has happened before and their efficacy can only be evaluated retrospectively. Therefore, an understanding of history is essential to questions of the desirability and feasibility of institutional change where such shifts are required from an ecological, social, or economic perspective. We further propose that institutional conflict arises from the differing goals and motives of resource management institutions at different scales. Our cases reveal that larger-scale institutions can be successful at achieving narrowly defined goals but often fall short of achieving socially desirable sustainable outcomes. Our findings support the use of narratives of community history, place, and being in considering the resilience and sustainability of social-ecological systems. We offer that historical ecology is complementary with institutional and economic approaches to the analysis of NRM institutions, and possesses a particular strength in linking ecology to the values and norms of small social groups. 相似文献
The aftermath of Hurricane Sandy brings to light the tenuous U.S. model of natural disaster management. Climatic extremes, like Sandy, are projected to increase in magnitude and frequency, calling upon societies to adapt appropriately to imminent threats. In this paper, we describe the knowledge and policy disconnect exposed by Sandy between what we submit are four key elements of adaptive capacity: resources, institutions, knowledge and innovation of technology. Our synthesis of multi-disciplinary expert knowledge and admonition from civil engineers, climatologists, and urban planners demonstrates the significance of mobilizing knowledge to design robust socio-ecological systems. We contrast the U.S. model to the Dutch system of climate adaptation to emphasize the feasibility, value, and effectiveness of adopting robust adaptive capacities, rather than policies steeped in reactionary responses. Such strategies that integrate coordination and imagination from members across society are imperative in translating scientific foresight into institutional action. The solution we offer is not only material for a more action-based discussion, but also provides an illustration of crafting policy that enhances adaptive capacities of socio-ecological systems. 相似文献