Seasonal Changes of Caloric Values in Different Organs of Butia capitata

对布迪椰子的幼叶、成熟叶、叶柄和根在不同季节的干重热值、去灰分热值和灰分含量进行了研究,结果表明:干重热值四个季节的平均值为成熟叶(20.65kJg-1)>幼叶(19.84kJg-1)>根(19.55kJg-1)>叶柄(18.77kJg-1),秋季的干重热值明显高于其它三个季节的干重热值,冬季的干重热值最低,去灰分热值与干重热值的变化趋势基本相同。灰分含量四个季节的平均值为根(5.14%)>叶柄(4.33%)>幼叶(4.21%)>成熟叶(3.97%)。成熟叶的灰分含量一直维持在比较低的水平,而幼叶的在秋季明显下降,在冬季明显上升,幼叶灰分含量的季节变化趋势与成熟叶的相同,叶柄灰分含量在冬季明显低于根部。布迪椰子这种不同器官在不同季节的热值和灰分的变化规律显示其具有较强的耐寒适应性。Seasonal changes of caloric value and ash content of Butia capitata were studied. The annual average caloric value was in the following order: mature leaves (20.65 kJ g-1) > young leaves (19.84 kJ g-1) > roots (19.55 kJ g-1) > petioles (18.77 kJ g-1). The organs showed maximum gross caloric values (GCV) in autumn and minimum ones in winter. Ash free caloric values (AFCV) varied as same as gross caloric values (GCV). The annual average ash content followed the order: roots (5.14%)> petioles (4.33%)> young leaves (4.21%)> mature leaves (3.97%). The ash content was lower in mature leaves, markedly decreased in young leaves during autumn, and then increased during winter. Seasonal changes of ash content in mature leaves were same with those in young leaves. Petioles had much lower ash content than roots during winter. Changes in ash content and caloric value of Butia capitata in different seasons were good energy use strategy for species with high cold resistance to adapt the low temperature.国家自然科学博士点基金项目资

Comparison of caloric values and ash contents in three palm species

通过测定厦门的三种棕榈植物布迪椰子、油棕和沼地棕的不同组分的热值和灰分含量。结果表明,布迪椰子各组分干重热值和去灰分热值由大到小的顺序为成熟叶>细根>幼叶>粗根>根茎>叶柄;油棕的为成熟叶>粗根>细根>幼叶>叶柄>根茎;沼地棕的为成熟叶>粗根>细根>幼叶>叶柄。布迪椰子的灰分含量高低顺序为细根>粗根>根茎>幼叶>叶柄>成熟叶,油棕的为成熟叶>幼叶>细根>粗根>叶柄>根茎;沼地棕的为幼叶>成熟叶>细根>粗根>叶柄。布迪椰子和沼地棕成熟叶的热值显著高于油棕,并且布迪椰子的成熟叶热值略低于沼地棕,但布迪椰子幼叶的热值显著高于沼地棕和油棕,布迪椰子的叶柄的热值显著低于沼地棕和油棕,说明耐寒性强的布迪椰子热值和灰分比耐寒性弱的油棕的分配策略更加合理,有利于提高其对低温的适应性,对植物引种具有重要的指导意义。An experiment was conducted to evaluate the caloric value and ash contents in various components of three palm species(Butia capitata,Elaeis guineensis,Acoelorraphe wrightii)from the nursery in the Xiamen Botanical Garden.The results showed that the gross caloric values(GCV)of Butia capitata in various components can be ranked in the decreasing order as follows:mature leaves>lower roots>young leaves>upper roots>rhizome>petioles;for Acoelorraphe wrightii,the order was:mature leaves>upper roots>lower roots>young leaves>petioles;for E.guineensis,the order was:mature leaves>upper roots>lower roots>young leaves>petioles>rhizomes.The ash free caloric values(AFCV)in different components also varied widely,and could be ranked almost in the same order as those of GCV.B.capitata ash contents in various components could be ranked in a decreasing order as follows:lower roots>upper roots>rhizomes>young leaves>petioles>mature leaves;for A.wrightii,the order was:young leaves>mature leaves>lower roots>upper roots>petioles;for E.guineensis,the order was:mature leaves>young leaves>lower roots>upper roots>petioles>rhizomes.The results indicated that the cold resistant B.capitata has a more reasonable distribution of caloric values and ash contents,this character may help to improve its adaptation to the low temperature.教育部博士教育基金~

塔干南缘四种植物水分关系的初步研究

水分是荒漠地区植分布的主要限制因素，在这一地区植物的抗旱能力是植被建立与保存成功与否的关键性因素。因此在研究荒漠植被的可持续利用模式时，研究植物本身和植物与环境间的水分关系是必须首先进行的工作。本文通过对植物清晨水势和日最低水势的季节变化、水势的日变化和季节变化、压力-容积参数的季变化、蒸腾作用和土壤水分含量变化的测定分析对骆驼刺（Alhagi sparsifolia B. Keller et Shap）、多枝柽柳（Tamarix ramosissima Lbd）、胡杨（Populus euphratica Oliv.）、头状沙拐枣（Calligonum caput-medusae Schrenk.）的水分关系进行了细致的研究，获得了如下初步结论：1. 水分亏缺或水分胁迫并未构成限制沙漠－绿洲过渡带现有四种植物存在的主要因素。2. 保持体内较高的相对含水量是四种植物在极端气候条件下抵御水分匮乏的共同反应。3. 四种植物对水分胁迫有不同的对应机制，如胡杨、多枝柽柳有很强的渗透调节功能；骆驼刺通过降低渗透势增加根系的吸水能力；而头状沙拐刺枣则是以减少蒸腾来阴止水分损失的。4. 灌溉对样地中根系与地下水有联系的胡杨和骆驼刺的水分状况影响不大，而对头状沙拐枣、红柳则很有益处。5. 从综合的水分生理指标来看，具有较高的水分利用效率的头状沙拐枣和能耐受很低渗透势的红柳都适合在有灌溉条件地方用于沙漠化防治；胡杨则对水分条件要求较高，在沙漠－绿洲过渡带发展胡杨应保证有一定的灌溉水源或较高的地下水位；深根系的骆驼刺植被一旦被破坏很难恢复，在利用时应加以足够的保护。加外，将植物的干旱生理适应类型初步确定为的抵抗型和宽容型两种。Water is the mainly limited factors to vegetation in arid area. At these sites, the ability to tolerate drought stress is a crucial factor for the establishment and survival of vegetation. So when the model of sustainable utility in arid vegetation was studied, the water relations of plant and water relations between environment and plant should be studied at first. In this article the next water parameters were measured carefully in Alhagi sparsifolia B. Keller et Shap, Tamarix ramosissima Lbd, Populous euphratica Oliv, Calligonum caput-medusae Schrenk, the season changes of predawn twig water potential and minimum twig water potential in diurnal, daily course of water potential and in season changes, season changes of PV-parameters, daily course of transpiration rate and changes of soil water content. From these measurements, the conclusions suggest: 1. Water deficits of water stress haven't been the main factor to limit growth of settled vegetation of four plant species in the belt between desert and oasis. The reason is the Alhagi sparsifolia, Tamarix ramosissima, Populus euphratica reached the ground water. 2. Keeping higher relative water content at incipience is the same reaction in four species to stress water deficits under extra climate conditions. 3. Four plant species had different way to treat water stress, e.g. Tamarix ramosissima and Populus euphratica owned strong osmotic adjustment, Alhagi sparsifolia decreased osmotic potential to reinforce the ability of absorption water in root system. For Calligonum caput-medusae, it was the way to decrease the transpiration to prevent water loss. 4. The effects of irrigation didn't make a good helpful for recovery of their water status in Populus euphratica and Alhagi sparsifolia, which the foot system reached ground water. But irrigation was helpful for Tamarix ramosisssima and Calligonum caput-medusae. 5. According to the physiological adaptation of drought, four species were defined in two types, stress to tolerance and stress resistance. 6. From the general criterions of water physiology in four plant species, Calligonum caput-medusae can save water in its body when water stress happened, Tamarix ramosissima can endure lower osmotic potential, both of them fit to prevent desertification in the area which can be irrigated. Populus euphratica need the more good water condition for growth, it's unfit to plant areas that water conditions is serious. The vegetation of Alhagi sparsifolia is difficult to recover caused by its deep root system it should be protect enough in utility

策勒绿洲外围不同地下水埋深下主要优势植物的分布和群落特征

对塔克拉玛干沙漠南缘策勒绿洲外围地下水埋深与主要优势植物分布和群落特点的研究结果表明,植物的分布和群落特征受地下水埋深变化的影响。但群落的组成成分和生物多样性受到地貌特征和地下水埋深的双重影响。群落的差异性和间断性大于群落的连续性和相似性。群落分布随地下水埋深的变化与其他荒漠地区在大的空间演替规律上相一致,但在群落类型、特别是低水位地段群落演替序列上有明显不同。随着地下水埋深的变化,植物群落依次为:低水位的骆驼刺群落,较低水位的柽柳群落,中低水位的柽柳、胡杨群落,较高水位的芦苇群落,高水位的苦豆子群落,其中地下水埋深6.0 m以上地段是植物群落类型、种类组成和生物多样性都较为丰富的地区。绿洲外围植物中柽柳具有最大的环境资源利用比率,对环境的适应性最强

长白山天然次生白桦林土壤CO_2释放通量研究

利用静态箱/气相色谱法测定了长白山天然次生白桦林土壤二氧化碳释放通量。在生长季节的春、夏、秋三个时间段对白桦林土壤CO2释放通量测定的结果表明:白桦林土壤呼吸的日变化和不同生长季节的变化均与温度的变化有明显的相关性。白昼的土壤CO2的释放通量始终高于夜晚,但白昼土壤CO2释放通量的峰值与气温的峰值相比具有一定的滞后性。土壤CO2释放通量夏季明显高于春秋两季,凋落物层对土壤CO2释放具有一定的影响,夏季去除凋落物层后土壤CO2释放通量高于未除凋落物层时CO2释放通量,而春秋两季则出现相反的结果。通过相关分析发现,有凋落物覆盖的土壤CO2释放通量与地下5cm温度相关性最好,而去除凋落物后土壤CO2释放通量则与地表温度相关性最高

塔克拉玛干沙漠南缘玉米对不同荒漠化环境的生理生态响应

为了研究玉米对不同荒漠化环境的适应性，以塔克拉玛干沙漠南缘策勒绿洲外围不同荒漠化程度下生长的玉米为试验材料，大田试验为手段，布置 3 个胁迫水平( 轻度荒漠化、中度荒漠化、重度荒漠化) ，研究了玉米的土壤含水率、植株高度、生物量分配、脯氨酸( Proline) 、丙二醛( MDA) 、可溶性糖( Sugar) 、叶绿素( Chl) 、叶绿素荧光参数、比叶面积( SLA) 等在不同胁迫梯度下的变化特征。结果显示: 随着荒漠化程度的加剧，玉米生物量、脯氨酸、丙二醛、叶绿素、类胡萝卜素、Chl a/b、叶绿素荧光参数都有不同幅度的下降; 中度荒漠化可溶性糖含量最低，重度最高，轻度介于两者之间; Car/Chl、比叶面积和地下生物量占总生物量的比重都随荒漠化程度的加剧，呈增加趋势。结果表明，荒漠化环境明显对玉米的生长产生了抑制作用; 随着荒漠化程度的加剧，玉米植株的光合色素含量降低，PSⅡ受到影响，从而影响植株的光合作用，使玉米物质的积累受到影响; 玉米自身通过在营养器官分配更多的能量和积累调控物质，并且在形态结构上也会发生某些改变以适应更恶劣的环境。随着胁迫程度的加剧，对其生长抑制愈严重

塔克拉玛干沙漠南缘9种禾本科牧草光系统Ⅱ特性

以新疆塔克拉玛干沙漠南缘策勒绿洲边缘广泛种植的中间偃麦草、新燕麦、无芒雀 麦、老芒麦、天山赖草、披碱草、矮生高羊茅、冰草和碱茅等9 种牧草为试验对象，测定暗适应20 min 后牧草叶片的快速叶绿素荧光诱导曲线，比较光系统Ⅱ( PSⅡ) 的特性，分析各牧草对本地区环境的适应能力． 结果表明: 天山赖草和披碱草的最大荧光( Fm ) 、PSⅡ最大光化学效率( Fv /Fm) 和单位面积反应中心的数量( RC /CSo) 的值均显著高于矮生高羊茅、冰草和碱茅，而初始荧光( Fo) 、单位反应中心吸收的光能( ABC /RC) 、单位反应中心捕获的能量( TRo /RC) 、单位反应中心耗散的能量( DIo /RC) 、荧光诱导曲线初始斜率( Mo) 值则低于矮生高羊茅、冰草和碱茅; 中间偃麦草、新燕麦、无芒雀麦和老芒麦的各值处于中间水平． 9 种牧草均受到恶劣气候条件的不同程度胁迫，PSⅡ反应中心的活性及电子传递受到抑制，其中，天山赖草和披碱草受到的影响较小，而矮生高羊茅、冰草和碱茅的PSⅡ结构和功能受到比较严重的影响，光合作用受抑制的程度较大

Effects of short time heat stress on photosystem II, Rubisco activities and oxidative radicals in Alhagi sparsifolia

生长在温带沙漠地区的植物在夏季时常遭受正午短时间的高温胁迫, 频繁和骤然的热胁迫在很大程度上限制了荒漠植物的光合作用。以塔克拉玛干沙漠南缘防风固沙的优势植物疏叶骆驼刺(Alhagi sparsifolia)为材料, 分别用叶绿素荧光诱导动力学和CO2响应方法分析热胁迫后光系统II (PSII)和RuBP羧化酶的热稳定性。结果表明: (1)在叶片温度超过43 ℃后PSII最大光化学量子产量、有活性反应中心数目、活力指数均出现明显的降低; 中高温度下PSII的电子供体侧比电子受体侧组分更容易受到热胁迫的伤害; 在58 ℃出现明显的K点(300 μs), 说明放氧复合体放氧结构受到破坏而失去活性。(2)随着叶片温度的上升, Rubisco活性先升高后降低, 在34 ℃时具有最高的活性水平。(3)叶片受到高温胁迫时, 细胞内氨态氮和活性氧分子等大量积累。(4)疏叶骆驼刺叶片处于短时间的高温环境时, 光合作用的光反应和暗反应阶段均表现出功能的不稳定性