Results 41 to 50 of about 27,177 (219)
Effects of Simulated Sea Level Rise on Storage and Origins of Sediment Organic Carbon and Decomposition of Fine Roots in Kandelia obovata Mangrove Ecosystem [PDF]
本研究以厦门曾营海岸三个不同高程样地的秋茄(Kandeliaobovata,以前学名为Kandeliacandel)红树林为研究对象。在模拟海平面上升80cm红树林(SLR80cm)、模拟海平面上升40cm红树林(SLR40cm)以及对照红树林(SLR0cm,相当于福建九龙江口红树林的滩面高程),探讨海平面上升对秋茄红树林生态系统地下部分有机碳过程的影响。 随海平面高度的增加,秋茄红树林底质有机碳和活性有机碳含量均逐渐增加;随着深度的增加,三块样地的底质有机碳含量、TN含量及C/N呈现逐渐减少的趋势 ...
黄莺莺
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Geographic risks to functional groups of mammals and birds from habitat loss in Mexico
Abstract There is a need to quantify the impact of habitat loss due to anthropogenic factors on different aspects of biodiversity, such as functional trait diversity represented by functional groups (FGs). We developed a metric to assess the weighted risk of loss of habitat for 33 FGs of mammals and 36 FGs of birds in Mexico based on potential ...
Fernando Mayani‐Parás +4 more
wiley +1 more source
为揭示三峡库区紫色土坡耕地草本植物根系对地埂土壤的固结作用的土力学机制,选取库区3种草本地埂植物为研究对象,对3种地埂植物根系的分布特征及抗拉性能研究,并分析3种地埂土壤的抗冲性和抗剪强度。研究结果表明,紫花苜蓿、蓑草、桂牧一号的根系总生物量分别为(79.37±1.26),(97.99±1.66),(71.76±1.96) g/m2,紫花苜蓿根系在0—10 cm土层分布最多,蓑草主要根系分布深度集中在10—20 cm,桂牧一号根系分布在0—30 cm土层深度范围内呈现出递增的趋势,在30—40 ...
周 萍 +4 more
doaj
Abstract Human development is a driver of global change and a major threat to biodiversity. Protected areas maintain and support biodiversity, but outside stressors, such as climate change and land use change, can negatively influence natural resources within protected areas.
Leah J. Rudge +2 more
wiley +1 more source
Study on the nitrogen removal process and influencing factors in the rhizosphere of Sesuvium portulacastrum floating bed [PDF]
大气是地球氮元素储量最大的氮库,由于氮气的三键结构十分稳定,打开它所需的能量较高,因此在工业革命以前,主要靠闪电固氮和生物固氮将其转化为人和生物可以利用的含氮化合物。然而随着人类社会的不断发展,为了满足人们生产生活的需要,大量氮元素被通过工业的方式固定下来,并随着化肥的滥用积累在环境中,造成氮循环的破坏,并产生水体富营养化现象。富营养化带来的恶果就是水体藻类大量繁殖,溶解氧急剧降低,造成鱼虾等水生生物的死亡等。因此,想要根除富营养化现象就必须将水体过量的氮、磷营养盐从水体脱除 ...
仇元
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Striking a Balance: Stakeholder Perceptions of Risk in Horse Racing
ABSTRACT Background Thoroughbred racing is a major industry, and in recent years, public concerns about equine safety have become more prominent, particularly in relation to on‐track injuries and fatalities. This has challenged the industry's social licence to operate (SLO).
Jessie McCarthy +2 more
wiley +1 more source
水体富营养化日益严重,水华频繁爆发,如何有效控制水华,治理富营养化水体是目前水环境领域的研究热点和前沿。目前湖泊藻类控制技术主要有:物理方法、化学法、生物法,但是这些方法都有其固有的缺点。利用植物化感作用抑制有害藻类生长具有廉价、生态安全等优点近年来备受关注。化感作用就是生物体产生的生物活性物质即化感物质在生物体之间传递信息并导致生物体相互作用。归纳了国内外不同生活型水生植物化感作用研究的主要成果(包括已报道的抑藻水生植物种类、已从水生植物体内和种植水中分离鉴定得到的化感物质 ...
吴振斌, 王红强
core
ABSTRACT Research on English‐Medium‐Instruction (EMI) highlights inadequate support for students transitioning from L1‐medium‐instruction to EMI. To date, little research has focused on how L2 students’ adaptation to an EMI environment influences their L2 learning motivation (LLM).
Kevin W. H. Tai
wiley +1 more source
为探讨草本植物根系对崩岗洪积扇土壤抗剪强度的影响,以巨菌草(Pennisetum sp.)和宽叶雀稗(Paspalum wettsteinii)为研究对象,采用WinRHIZO根系分析系统对根系特征进行定量分析,并采用原位剪切试验测定崩岗洪积扇各土层的抗剪强度。结果表明:(1)根系能够改善土壤的结构及水分状况。(2)2种草本植物根系均主要分布在0—5 cm土层,该层巨菌草根系各参数值是该草种根系均值的3.1~4.39倍,宽叶雀稗的则为2.23~2.57倍;随着土层深度的增加,巨菌草根系参数呈对数函数减小,
李 +6 more
doaj

