Effect of Phosphorus Concentration on the Growth of Cattail Callus Cells

Abstract

This investigation examined the growth of Typha latifolia (cattail) callus cells grown in five (0, 11, 22, 33, 44 mg L^?1) different phosphorus concentrations. The cells were grown for two successive subcultures on semi‐solid media, and subsequently in suspension culture with the same phosphorus levels. On semi‐solid media, the fresh weight of the cells varied by a maximum of 36% through both subcultures. The 33 mg L^?1 phosphorus supplied in the original Gamborgs B5 media promoted the greatest fresh weight of the cells in suspension culture over all other concentrations tested. When grown in suspension culture with 0 and 11 mg L^?1 phosphorus, the cells showed a 42 and 29% reduction in fresh weight, respectively. Incubating the cells with 22 and 44 mg L^?1 phosphorus caused a 20 and 13% reduction in fresh weight, respectively. In addition, this study compared the phosphorus concentration of callus cells against literature‐reported values of whole cattail plants incubated at similar phosphorus concentrations. Data from this study demonstrate that when the cattail callus cells and whole plants are exposed to similar phosphorus concentrations, the phosphorus concentration in the plant leaves is within the confidence interval ( p ≤ 0.05) of the phosphorus concentration in the cattail callus cells. This suggests that cattail callus cells can be used to predict the concentration of phosphorus in cattail leaves when they are supplied with similar phosphorus levels. If this relationship between callus cells and whole plants is found to be applicable to other marsh plant species, stormwater wetland managers can use callus cells as a rapid method to screen plants for their capacity to absorb phosphorus before the plant is established in a wetland. This can increase the effectiveness of the wetland to absorb unwanted pollutants from the stormwater entering the site.     

1960—2009年图们江上游湿地景观变化的遥感监测

基于景观生态学原理,在地理信息系统和遥感技术的支持下,利用地形图、Landsat影像数据,提取图们江上游1960年、1977年、1985年、1999年和2009年的湿地信息,分析了该地区近50 a来湿地的分布状况和变化特征。结果表明:从湿地面积的变化特征上,该区域湿地面积减少一半,天然湿地的比例在降低,沼泽变化最大,减少了68.17%,人工湿地比例增大。从湿地景观格局的变化特征上,近50 a,该区域湿地景观斑块个数减少了近2/3,平均斑块面积增加1倍,景观多样性指数、景观破碎化指数及景观均匀性指数均在一定程度上减少。其中人类活动是图们江上游天然湿地减少的主要因素。     

A biodiversity monitoring framework for practical conservation of grasslands and shrublands

Comprehensive and standardized biodiversity monitoring schemes are needed to build scientifically sound decision-making tools for biodiversity conservation. Based on a thorough review of published literature, we propose a novel biodiversity monitoring framework to unify conservation theory and practice. The framework is built on the inter-connection among different types of indicators, and on the systematic articulation of their relationships into seven indicator approaches. Semi-natural grasslands and shrublands in Europe, which still lack a common biodiversity monitoring scheme, are used as a model for the framework. Different biotic indicators have been widely used to estimate the state of biodiversity, but we integrate these with biodiversity drivers, i.e. factors driving changes in biodiversity, to track biodiversity response to environmental changes. Precise information on biodiversity drivers (e.g. past and present management or disturbance regimes, environmental conditions, landscape patterns) has an effective indicator value, but this is often not taken into account in monitoring schemes. Our framework can be used to detect gaps in available data, translate indicator systems into practical conservation, identify combined sets of indicators to monitor biodiversity in target habitats, and recognize most suitable surrogates when information for some indicators is missing. We also take into account the effect of regional species pools in order to consider large-scale historical and biogeographical processes. We propose general guidelines to create validate and launch biodiversity monitoring frameworks for target habitats in the light of current examples of biodiversity conservation schemes (e.g. Natura 2000 in Europe).     

Spatial and temporal variation of nitrous oxide and methane flux between subtropical mangrove sediments and the atmosphere

We quantified spatial and temporal variations of the fluxes of nitrous oxide (N₂O) and methane (CH₄) and associated abiotic sediment parameters across a subtropical river estuary sediment dominated by grey mangrove (Avicennia marina). N₂O and CH₄ fluxes from sediment were measured adjacent to the river (“fringe”) and in the mangrove forest (“forest”) at 3-h intervals throughout the day during autumn, winter and summer. N₂O fluxes from sediment ranged from an average of −4 μg to 65 μg N₂O m⁻² h⁻¹ representing N₂O sink and emission. CH₄ emissions varied by several orders of magnitude from 3 μg to 17.4 mg CH₄ m⁻² h⁻¹. Fluxes of N₂O and CH₄ differed significantly between sampling seasons, as well as between fringe and forest positions. In addition, N₂O flux differed significantly between time of day of sampling. Higher bulk density and total carbon content in sediment were significant contributors towards decreasing N₂O emission; rates of N₂O emission increased with less negative sediment redox potential (E_h). Porewater profiles of nitrate plus nitrite (NO_x⁻) suggest that denitrification was the major process of nitrogen transformation in the sediment and possible contributor to N₂O production. A significant decrease in CH₄ emission was observed with increasing E_h, but higher sediment temperature was the most significant variable contributing to CH₄ emission. From April 2004 to July 2005, sediment levels of dissolved ammonium, nitrate, and total carbon content declined, most likely from decreased input of diffuse nutrient and carbon sources upstream from the study site; concomitantly average CH₄ emissions decreased significantly. On the basis of their global warming potentials, N₂O and CH₄ fluxes, expressed as CO₂-equivalent (CO₂-e) emissions, showed that CH₄ emissions dominated in summer and autumn seasons (82-98% CO₂-e emissions), whereas N₂O emissions dominated in winter (67-95% of CO₂-e emissions) when overall CO₂-e emissions were low. Our study highlights the importance of seasonal N₂O contributions, particularly when conditions driving CH₄ emissions may be less favourable. For the accurate upscaling of N₂O and CH₄ flux to annual rates, we need to assess relative contributions of individual trace gases to net CO₂-e emissions, and the influence of elevated nutrient inputs and mitigation options across a number of mangrove sites or across regional scales. This requires a careful sampling design at site-level that captures the potentially considerable temporal and spatial variation of N₂O and CH₄ emissions.     

A regulatory role for phenol oxidase during decomposition in peatlands

Unique peatland properties, such as their ability to preserve intact ancient human remains (bog bodies) and to store globally significant quantities of atmospheric CO₂, can be attributed to their low rates of enzymic decomposition. Peatland soils are normally devoid of molecular oxygen in all, but the uppermost layer, and thus enzymes such as phenol oxidase, which require molecular oxygen for their activity, are rarely active. Interestingly, even the activities of enzymes such as hydrolases that have no oxygen requirement, are also extremely limited in peatlands. Here, we show that those low hydrolase activities can be indirectly attributed to oxygen constraints on phenol oxidase. On addition of oxygen, phenol oxidase activity increased 7-fold, P<0.05, a response that allowed phenolic depletion in the peatland soil. Phenolic materials are highly inhibitory to enzymes and their lower abundance allowed higher hydrolase activities (β-glucosidase 26%, P<0.05, phosphatase 18%, P<0.05, sulphatase 47%, P<0.01, xylosidase 16%, P<0.05 and chitinase 22%, P<0.05). Thus, oxygen constraints upon phenol oxidase activity promote conditions that inhibit decomposition. This mechanism has important implications for preservation of archaeological organic materials, sequestration of atmospheric CO₂ and potentially in the preservation of food and treatment of water pollution.     

基于MapInfo的北固山湿地地理信息系统

针对湿地生态环境管理中普遍存在的问题,采用MapInfo作为开发平台,利用MapBasic为二次开发语言,以北固山湿地为研究对象,对空间数据与属性数据进行有效集成,研制和开发了基于MapInfo的湿地地理信息系统。系统实现了数据的系统化管理,具备数据的编辑、查询、统计分析及报表的自动生成、专题图制作等数据分析与处理能力,能够为湿地管理与决策提供有力的依据。     

陕西黄河湿地夏季鸟类资源调查

采用样线法对陕西黄河湿地4种生境的鸟类资源进行了调查,共记录到鸟类61种,隶属于15目33科。其中国家Ⅰ级重点保护鸟类1种,国家Ⅱ级重点保护鸟类2种,陕西省重点保护鸟类4种。＂国家保护的有益的或者有重要经济、科学研究价值的陆生野生动物＂52种。鸟类属于10个分布型,其中东洋型鸟类占22.95%,古北型鸟类占16.39%,反映了该地区的鸟类区系从东洋界向古北界鸟类过渡的特征。     

三江自然保护区丹顶鹤春季觅食生境初步研究

采用样方因子测定法对三江国家级自然保护区丹顶鹤春季觅食生境进行调查研究的结果表明:丹顶鹤春季主要在以苔草、小叶章为主的沼泽湿地中觅食;觅食地植被高度小于40 cm,植被密度低于400株/m2,植被盖度为0～25%,觅食地水深多为5～15 cm,人类干扰距离大于1 500m;人为活动严重影响着丹顶鹤的觅食;春季丹项鹤有在...     

Progress towards international targets for protected area coverage in mountains: A multi-scale assessment

Through the Convention on Biological Diversity (CBD), the world’s governments recently adopted a target to protect “at least 17% of terrestrial and inland water areas” by 2020. One of the CBD’s thematic programmes of work focuses on mountains, given their importance for biodiversity and other ecosystem services, and their vulnerability to global change. We evaluated current levels of protection for mountains at multiple scales. Encouragingly, the CBD’s 17% target has already been almost met at a global scale: 16.9% of the world’s mountain areas outside Antarctica fall within protected areas. However, protection of mountain areas at finer scales remains uneven and is largely insufficient, with 63% (125) of countries, 57% (4) of realms, 67% (8) of biomes, 61% (437) of ecoregions and 53% (100) of Global 200 priority ecoregions falling short of the target. The target also calls for protected areas to be focussed “especially [at] areas of particular importance for biodiversity”. Important Bird Areas and Alliance for Zero Extinction sites represent existing global networks of such sites. It is therefore of major concern that 39% and 45% respectively of these sites in mountain areas remain entirely unprotected. Achievement of the 2020 CBD target in mountain regions will require more focused expansion of the protected area network in addition to enhanced management of individual sites and the wider countryside in order to ensure long term conservation of montane biodiversity and the other ecosystem services it provides.     

金河林业局湿地资源现状与保护对策

文章通过对金河林业局湿地的现状、类型与生物多样性的阐述与湿地综合效益评价分析,提出了对金河林业局保护湿地的措施。