Can We Manage for Resilience? The Integration of Resilience Thinking into Natural Resource Management in the United States

The concept of resilience is now frequently invoked by natural resource agencies in the US. This reflects growing trends within ecology, conservation biology, and other disciplines acknowledging that social–ecological systems require management approaches recognizing their complexity. In this paper, we examine the concept of resilience and the manner in which some legal and regulatory frameworks governing federal natural resource agencies have difficulty accommodating it. We then use the U.S. Forest Service’s employment of resilience as an illustration of the challenges ahead.     

Automated and continuous redox potential measurements in soil

Redox potential (Eh) describes the electrical state of a matrix. In soils, Eh is an important parameter controlling the persistence of many organic and inorganic compounds. A popular, but also criticized, manual measuring method makes use of a small tip of Pt placed on a copper wire that is placed in the soil; a reference electrode is placed in the same soil at a fixed distance. Fluctuations in redox potential values measured in the soil can be very large and depth-dependent. This will be overlooked when making single-point measurements. We developed the datalogger Hypnos 2.0 for continuous redox potential and temperature measurements at various depths in the soil and without disturbance of the site. Hypnos is field-deployable, relatively cheap, and runs on batteries. The datalogger can use a "sleep mode" between sampling events. In sleep mode, there is no constant voltage on the Pt wire or the reference electrode, but there is only a short pulse during sampling. We did not measure an effect of this short pulse on the measured redox potential. In sandy soils in mesocosms and in a salt marsh soil we measured changes in the Eh as large as from -400 to +100 mV within 4 d, and daily cycles of 200 mV. Both absolute redox potential values and their diurnal variations were depth-dependent. Because single redox measurements are insufficient in describing redox conditions in some soil systems, Hypnos can be a powerful tool when studying the effects of fluctuating redox conditions on metal availability and pollutant degradation.     

气候变化、中国的崛起和全球恐怖主义

这个不确定的时代该如何去应对．许多活跃的知识分子竞相提出自己的策略和建议——尤其是近两年．各种观点或冷静或激扬,交相错映,端的是热闹非凡。地理学者哈姆·迪伯利的《何以地理学至关紧要：美国面临的三大挑战：气候变化、中国的起和全球恐怖主义》一书亦是此类著作。它从地缘政治学的角度出发．提出了美国当前所面临的三大挑战．并认为．倘若不能成功解决这三大挑战．美国势必将在世界新格局的竞争中败下阵来。