The use of raw clay in housing construction dates back from ancient times and is still living on. Traditional habitat comprising various buildings all over different places of our planet, give evidence. Among any othe...The use of raw clay in housing construction dates back from ancient times and is still living on. Traditional habitat comprising various buildings all over different places of our planet, give evidence. Among any other pathologies affecting naked earthen walls, the rain water wash remains a major concern and deserves careful consideration. Which justifies the interest of this research focused on the protection means of such types of walls. This article relates the experiment conducted on low walls made out of raw clay mixed with composite protecting products （traditional and modern ones as well）, being tested to intensive water floods. The result of the tests assessed through efficiency of the protecting materials, shows that the locust bean tree （local tree） fruit husk extract added to raw clay mortar and carefully blended seems to provide better ability to protect walls against water assault. Moreover, consistency check and plasticity reveal better performance in clay material properties.展开更多
The alien woody legume, black locust （Robinia pseudoaca-cia）, has invaded Japanese black pine （Pinus thunbergii） forests located in Japan’s coastal plain and hill regions where gaps are formed in pine forests aft...The alien woody legume, black locust （Robinia pseudoaca-cia）, has invaded Japanese black pine （Pinus thunbergii） forests located in Japan’s coastal plain and hill regions where gaps are formed in pine forests after nematode infestation. Nitrogen fixation by legumes acceler-ates N cycling in forest ecosystems. We studied temporal change in the annual tree-ring resolution N stable isotope composition （δ15N, a per mil deviation of δ15N/14N ratio, relative to atmospheric N2δ15N=0‰） at two natural locations of Japanese black pine forest with black locust that differed in the time since black locust establishment （Shohnai in north-east and Kita-Kyushu in southwest Japan）. Analyzed tree-rings covered the period from 1990/1992 to 2009. N acquisition by Japanese black pine from black locust N input to the soil was evidenced by temporal shifting of N stable isotope composition on the annual pine tree rings. With pro-gressive development of the forest stand,δ15N values of earlier tree-ringsδ15N of -5‰） from black pine associated with black locust shifted to-wards values similar to those of black locustδ15N values nearly to-1‰）, which suggests acquisition of N by N2 fixation （Shohnai site）. In con-trast, in a forest where black locust had settled for two or three genera-tions, in a black pine stand （Kita-Kyushu site）, longer periods of N en-richment in the soil were reflected in the elevated tree-ringδ15N values of newly established black pine trees. Based on tree-ringδ15N data from the Shohnai site, we determined that about 10 years after black locust establishment, soil N had already been enriched by black locust N, this, in turn, contributed to N fertilization of surrounding trees in mixed stands.展开更多
为了更深入的了解复垦地不同植物配置模式的群落学特征,更好的进行复垦地不同植物配置模式物种多样性监测,采用CTFS(Centre for Tropical Forest Science)样地建立标准,于2010年在安太堡露天矿区排土场复垦地建立了刺槐+油松混交林配置...为了更深入的了解复垦地不同植物配置模式的群落学特征,更好的进行复垦地不同植物配置模式物种多样性监测,采用CTFS(Centre for Tropical Forest Science)样地建立标准,于2010年在安太堡露天矿区排土场复垦地建立了刺槐+油松混交林配置模式的固定监测样地。通过对野外调查资料的初步分析以及与复垦初期种植模式对比研究得出:复垦17年后,样地内除刺槐和油松外,还有入侵定居种榆树,共10073个活个体,样地内整体存活情况较好,枯死个体仅占样地内个体总数的0.7%。复垦17年后样地优势种为刺槐,从胸高断面积和重要值方面均表现出明显的优势度。样地内所有个体径级呈明显倒"J"型分布,总体更新状况较好;各树种的径级结构呈峰型或"L"型。在树种的空间分布格局上,初期种植刺槐和油松均呈明显均匀分布,复垦17年后刺槐、油松和榆树的空间分布与种子性质和生境密切相关,且由于初期植被根系覆盖率低,地形土壤条件较不稳定,自然滑动及雨水冲刷造成了复垦17年后刺槐和油松个体发生了一定的位移。展开更多
文摘The use of raw clay in housing construction dates back from ancient times and is still living on. Traditional habitat comprising various buildings all over different places of our planet, give evidence. Among any other pathologies affecting naked earthen walls, the rain water wash remains a major concern and deserves careful consideration. Which justifies the interest of this research focused on the protection means of such types of walls. This article relates the experiment conducted on low walls made out of raw clay mixed with composite protecting products （traditional and modern ones as well）, being tested to intensive water floods. The result of the tests assessed through efficiency of the protecting materials, shows that the locust bean tree （local tree） fruit husk extract added to raw clay mortar and carefully blended seems to provide better ability to protect walls against water assault. Moreover, consistency check and plasticity reveal better performance in clay material properties.
文摘The alien woody legume, black locust （Robinia pseudoaca-cia）, has invaded Japanese black pine （Pinus thunbergii） forests located in Japan’s coastal plain and hill regions where gaps are formed in pine forests after nematode infestation. Nitrogen fixation by legumes acceler-ates N cycling in forest ecosystems. We studied temporal change in the annual tree-ring resolution N stable isotope composition （δ15N, a per mil deviation of δ15N/14N ratio, relative to atmospheric N2δ15N=0‰） at two natural locations of Japanese black pine forest with black locust that differed in the time since black locust establishment （Shohnai in north-east and Kita-Kyushu in southwest Japan）. Analyzed tree-rings covered the period from 1990/1992 to 2009. N acquisition by Japanese black pine from black locust N input to the soil was evidenced by temporal shifting of N stable isotope composition on the annual pine tree rings. With pro-gressive development of the forest stand,δ15N values of earlier tree-ringsδ15N of -5‰） from black pine associated with black locust shifted to-wards values similar to those of black locustδ15N values nearly to-1‰）, which suggests acquisition of N by N2 fixation （Shohnai site）. In con-trast, in a forest where black locust had settled for two or three genera-tions, in a black pine stand （Kita-Kyushu site）, longer periods of N en-richment in the soil were reflected in the elevated tree-ringδ15N values of newly established black pine trees. Based on tree-ringδ15N data from the Shohnai site, we determined that about 10 years after black locust establishment, soil N had already been enriched by black locust N, this, in turn, contributed to N fertilization of surrounding trees in mixed stands.
文摘为了更深入的了解复垦地不同植物配置模式的群落学特征,更好的进行复垦地不同植物配置模式物种多样性监测,采用CTFS(Centre for Tropical Forest Science)样地建立标准,于2010年在安太堡露天矿区排土场复垦地建立了刺槐+油松混交林配置模式的固定监测样地。通过对野外调查资料的初步分析以及与复垦初期种植模式对比研究得出:复垦17年后,样地内除刺槐和油松外,还有入侵定居种榆树,共10073个活个体,样地内整体存活情况较好,枯死个体仅占样地内个体总数的0.7%。复垦17年后样地优势种为刺槐,从胸高断面积和重要值方面均表现出明显的优势度。样地内所有个体径级呈明显倒"J"型分布,总体更新状况较好;各树种的径级结构呈峰型或"L"型。在树种的空间分布格局上,初期种植刺槐和油松均呈明显均匀分布,复垦17年后刺槐、油松和榆树的空间分布与种子性质和生境密切相关,且由于初期植被根系覆盖率低,地形土壤条件较不稳定,自然滑动及雨水冲刷造成了复垦17年后刺槐和油松个体发生了一定的位移。
