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51.
52.
Agroforestry in the Western Ghats (WG) of peninsular India and satoyama in rural Japan are traditional land-use systems with
similar evolutionary trajectories. Some of their relevance was lost by the middle of the twentieth century, when modern agricultural
technologies and urbanisation engineered shifts in emphasis towards maximising crop production. There has been, however, a
resurgence of interest in traditional land-use systems recently, in view of their ability to provide ecosystem services. Both
agroforestry and satoyama are thought to be harbingers of biological diversity and have the potential to serve as “carbon
forests.” Carbon (C) stock estimates of the sampled homegardens in WG ranged from 16 to 36 Mg ha−1. Satoyama woodlands owing to variations in tree stocking and management conditions indicated widely varying C stocks (2–279 Mg ha−1). Agroforestry and satoyama also differ in nature, complexity, and objectives. While agroforestry involves key productive
and protective functions, and adopts ‘intensive management’, the satoyama woodlands are extensively managed; understorey production
is seldom a consideration. Differences in canopy architecture (multi-tiered structure of agroforestry vs. the more or less
unitary canopy of satoayama) and land ownership pattern (privately owned/managed agroforestry holdings vs. community or local
government or privately owned and mostly abandoned satoyamas) pose other challenges in the transfer and application of knowledge
gained in one system to the other. Nonetheless, lessons learnt from satoyama conservation may be suitable for common pool
resource management elsewhere in Asia, and aspects relating to understorey production in agroforestry may be relevant for
satoyama under certain scenarios. 相似文献
53.
焚烧飞灰预处理工艺及其无机氯盐的行为研究 总被引:1,自引:1,他引:1
研究表明WCCB(水洗+烧结)预处理工艺能更高效更节能地去除飞灰中的氯化物,以利于其作为水泥原料的使用.水洗工艺条件为两次水洗、水固比均为3∶1,搅拌速度均为150 r.min-1,第一次水洗时间5 min,第二次水洗时间10 min;利用原焚烧炉进行烧结处理,温度为1 000℃,10%氧气含量,停留时间1 h.本研究尝试了3种焚烧飞灰:节煤器出来的飞灰、石灰干法中和酸性气体后布袋收集的飞灰、NaHCO3中和酸性气体后布袋收集的飞灰.经该工艺处理后,焚烧飞灰残渣量减少20%以上,氯减少94%以上,尤以NaHCO3中和得到的飞灰削减量为最,分别达到了72.1%和99.8%.采用同步辐射的X射线吸收近边精细结构(X-ray absorption near edge structure,XANES)和普通X射线衍射(X-ray Diffraction,XRD)相结合的方法研究分析无机氯盐在工艺过程中的行为,发现焚烧飞灰中主要的氯盐主要有NaCl、KCl和CaCl2.焚烧炉烟气净化系统的酸中和剂会影响无机氯盐的生成.焚烧飞灰中难溶性无机氯盐的结构与Friedel’s盐相似,并且与CaCl2有关系. 相似文献
54.
Anaerobic transformation of chlorophenols in methanogenic sludge unexposed to chlorophenols 总被引:2,自引:0,他引:2
Transformation of all 19 chlorophenol (CP) isomers was investigated in a laboratory anaerobic methanogenic sludge that had not been exposed to synthetic chemicals. Concentration of CP was analyzed over time to calculate disappearance rate constants using first-order reaction kinetics and all possible CP degradation pathways were estimated. The rate constants ranged between 0.46 x 10(-3) and 0.161 day(-1). CPs were transformed via dechlorination. The chlorine atom at the ortho-position was the most easily dechlorinated, whereas dechlorination rate at the para-position was lowest. The overall pathways of CP transformation were much less diverse than that we previously found for contaminated sediment. The Dolfing hypothesis of microbial selection of the most thermodynamically favorable pathways was not applicable for CP transformation in this study as well as previous study performed by our group. 相似文献
55.
4种水生植物根际磷素耗竭效应的比较 总被引:2,自引:5,他引:2
利用短期盆栽试验和抖根法研究了喜旱莲子草(Alternanthera philoxeroides)、香蒲(Typha latifolia)、慈姑(Sagittaria sagittifolia)和芦苇(Phragmites communis)4种水牛植物的根际磷素耗竭效应,分析了植物根冠比、根系形态、磷素吸收有效性和磷素利用有妓性等差异,探讨了植物根际磷素耗竭效应的吸收利用调控机制.结果表明,与非根际土壤(有效磷含量为167.53ìg穏-1)相比,喜旱莲子草、香蒲、慈姑和芦苇根际土壤的有效磷含量分别减少至80.17、124.37、155.38和161.75ìg穏-1,水溶性磷含量分别减少了81%、42%、18%和16%.喜旱莲子草根系较小,但磷素吸收有效性高(1.32 mg·m-1),其磷素利用有效件不高(0.34 g·mg-1);香蒲的磷素吸收有效性虽然比喜旱莲子草低许多(0.52 mg·m-1),但其有强大的根系,且磷素利用有效性高(0.64 g·mg-1)、根冠比大(0.35).喜旱莲子草和香蒲耗竭根际磷素的能力高于慈姑和芦苇. 相似文献
56.
Takaoka M Yamamoto T Shiono A Takeda N Oshita K Matsumoto T Tanaka T 《Chemosphere》2005,59(10):1497-1505
A limited amount of information exists regarding the relationship between the chemical form of copper and the formation of chlorinated aromatics in fly ash. To understand the effects of the various forms of copper on the formation of chlorinated aromatics in real fly ash, we determined the chemical forms of copper present in various types of real fly ash using X-ray absorption near edge structure (XANES) and evaluated the relationship between the chemical forms of copper and the formation of chlorinated aromatics. Copper chloride hydroxide (CuCl2 x 3Cu(OH)2) and cuprous chloride (CuCl) were the predominant copper species found in real fly ash. Although pure cupric chloride (CuCl2) is known to be the most active catalyst for the formation of chlorinated aromatics under experimental conditions with synthetic fly ash, CuCl2 was not found in every real fly ash sample. The amount of copper chloride hydroxide was positively correlated with the formation of chlorinated aromatics in real fly ash and is, consequently, considered to be one of the key species involved in the formation of chlorinated aromatics. 相似文献
57.
Kaoru Kakinuma Takehiro Sasaki Undarmaa Jamsran Toshiya Okuro Kazuhiko Takeuchi 《Environmental management》2014,54(4):888-896
Applying the threshold concept to rangeland management is an important challenge in semi-arid and arid regions. Threshold recognition and prediction is necessary to enable local pastoralists to prevent the occurrence of an undesirable state that would result from unsustainable grazing pressure, but this requires a better understanding of the pastoralists’ perception of vegetation threshold changes. We estimated plant species cover in survey plots along grazing gradients in steppe and desert-steppe areas of Mongolia. We also conducted interviews with local pastoralists and asked them to evaluate whether the plots were suitable for grazing. Floristic composition changed nonlinearly along the grazing gradient in both the desert-steppe and steppe areas. Pastoralists observed the floristic composition changes along the grazing gradients, but their evaluations of grazing suitability did not always decrease along the grazing gradients, both of which included areas in a post-threshold state. These results indicated that local pastoralists and scientists may have different perceptions of vegetation states, even though both of groups used plant species and coverage as indicators in their evaluations. Therefore, in future studies of rangeland management, researchers and pastoralists should exchange their knowledge and perceptions to successfully apply the threshold concept to rangeland management. 相似文献
58.
The Japanese rural coastal areas are inherently vulnerable to typhoons and tsunamis. Their vulnerability has been further
increasing recently, in part due to social factors such as the aging of society and depopulation. Following the Kobe earthquake
of 1995, the Japanese government has promoted the Voluntary Disaster Preparedness Organization (VDPO) to build communities
that are more sustainable and resilient to natural disasters. However, studies indicate that some VDPO activity has stagnated.
The present study focuses on a rural coastal area in Japan and examines whether VDPO impacts residents’ awareness of disaster
preparedness and also examines ties among the community. The study relies on a questionnaire survey. It reveals that VDPO
contributes to improving both awareness of disaster preparedness and ties in the community. 相似文献
59.
To formulate successful phytostabilization strategies in a shooting range soil, understanding how heavy metals are immobilized at the molecular level in the rhizosphere soil is critical. Lead (Pb) speciation and solubility in rhizosphere soils of five different plant species were investigated using extended X-ray absorption fine structure (EXAFS) spectroscopy and chemical extraction. The EXAFS analysis indicated that Pb occurred as PbCO (37%), Pb sorbed to organic matter (Pb-org: 15%), and Pb sorbed to pedogenic birnessite and/or ferrihydrite (Pb-ox: 36%) in the bulk soil. Comparison of the EXAFS spectra between bulk and rhizosphere soils demonstrated notable differences in fine structure, indicating that Pb species had been modified by rhizosphere processes. The estimated proportion of PbCO (25%) in the buckwheat soil was smaller than the other rhizosphere soils (35-39%). The addition of P significantly reduced Pb solubility in the bulk and rhizosphere soil except in the rhizosphere of buckwheat, for which the Pb solubility was 10-fold greater than in the other P-amended soils. This larger solubility in the buckwheat rhizosphere could not be explained by the total Pb speciation in the soil but was presumably related to the acidifying effect of buckwheat, resulting in a decrease of the soil pH by 0.4 units. The reduced Pb solubility by P amendment resulted from the transformation of preexisting PbCO (37%) into Pb(PO)Cl (26-32%) in the bulk and rhizosphere soils. In the P-amended rhizosphere soils, Pb-org species were no longer detected, and the Pb-ox pool increased (51-57%). The present study demonstrated that rhizosphere processes modify Pb solubility and speciation in P-amended soils and that some plant species, like buckwheat, may impair the efficiency of Pb immobilization by P amendments. 相似文献
60.
Tsuyoshi Takeuchi 《Behavioral ecology and sociobiology》2011,65(8):1559-1566
Male butterflies compete over mating territories via aerial interactions. It has often been suggested that flight performance,
and thus flight-related traits, would play an important role in butterflies’ contest resolution; however, most studies have
not demonstrated a clear relationship between these traits and territory ownership in butterflies. Males of the satyrine butterfly
Lethe diana compete over territories via linear chases, a behavior that is uncommon among butterflies: rather, contests of most butterfly
species consist of circling flights. In the present study, some morphological and physiological traits of L. diana were compared between territory owners and intruders to search for traits correlated with resource holding power (RHP). Territory
owners had higher flight-muscle ratio (FMR) and were heavier than intruders, indicating that flight performance plays a key
role in their contest resolution. Contest duration was not affected by the owners’ FMR or body mass, and thus I obtained no
evidence supporting the hypothesis that contestants assess their relative RHP before making a decision to retreat. I speculate
that the fact that these traits had an effect on territorial status in L. diana was a result of the characteristics of the contest behavior of this butterfly. During their contests, males L. diana fly faster in their linear flights than males of most other butterflies, which engage in slower circling flights. Therefore,
males of L. diana probably need higher flight performance capabilities in order to win their contests. 相似文献