ine<br /> Koneksi h Internet t Internet isearch,<img src="http://upload.wikimedia.org/wikipedia/commons/d/dc/Aircraft_ground_handling.jpg"/>tsearchbsearchs Internet , Internet s Free t Tag n<embed src=""/>c Free t<embed src=""/> searcho<embed src=""/>y Tag f Koneksi ud Koneksi ,h Internet s Internet msearchasearchs Free ta Tag   Tag h<br />solute concentration of urine is equal to the solute<br />concentration of the body fluids.<br />Water conservation<br />by mammalian<br />kidneys<br />Related topics Solar radiation and climate(C1) Plants and water (D2)<br />Microclimate (C2) Ecosystem patters (S1)<br />The properties of water (D1)<br />E1 温度与代谢<br />要 点<br />恒温动物和变<br />温动物<br />按照有机体的体温调节过程有可能对有机体进行分类。<br />一种可能的划分是恒温动物和变温动物。当环境温度<br />升高时，恒温动物保持着大致恒定的体温，而变温动<br />物的体温随环境温度而改变。这种分类的一个问题是，<br />即使是典型的恒温动物也经历了降低体温的时期。在<br />有机体之间，可供选择的另一种划分描述如下。<br />E1 TEMPERATURE AND<br />METABOLISM<br />It is possible to categorize organisms according to their<br />temperature regulation processes,One possible division<br />is between homeotherms and poikilotherms,As<br />environmental temperature rises,homeotherms maintain<br />an approximately constant body temperature,while the<br />body temperature of poikilotherms varies with<br />environmental temperature,One problem with this<br />classification is that even classic homeotherms<br />experience periods of reduced temperature.,an<br />alternative distinction between organisms is described<br />below.<br />Key Notes<br />Homeotherms and<br />poikilotherms<br />外温动物和内<br />温动物<br />像爬行动物等有机体属外温动物，它们很大程度地依<br />赖于外来的热来提高自己的体温。内温动物是能够在<br />体内产热以升高体温的有机体。鸟和哺乳动物属于这<br />一类。 热中性区 （ thermoneutral zone）是环境的温度范<br />围，在这个温度范围内，内温动物仅使用一个最小的<br />代谢率以维持恒定的体温。环境温度离热中性区越远，<br />内温动物维持恒定体温消耗的能量越多。<br />热 交 换 所有的有机体从它们的环境中得到热，也将产生的热<br />散失到它们的环境中。种种生理学和行为学的机理被<br />用于调节体热。尽管有这些机理，外温性动物的体温<br />还是明显地随环境条件而改变。<br />Ectotherms are organisms such as plants,reptiles and<br />protista which are largely reliant on external sources of<br />heat to raise their body temperature.endotherms are<br />organisms capable of generating heat internally in order to<br />raise their body temperature,Birds and mammals make up<br />this group,The thermoneutral zone is the range of<br />enmironmental temperatures in which an endotherm has<br />only to exert a minimum metabolic effort in order to<br />maintain a constant body temperature,The further away<br />from the thermoneutral zone that the environmental<br />temperature moves,the more energy the endotherm has to<br />expend to maintain body temperature,<br />Ectotherms and<br />endotherms<br />All organisms gain heat from and lose heat to their<br />environment as well as producing heat,A variety of<br />physiological and behavioral mechanisms are used to<br />regulate heat,Despite these mechanisms,the body<br />temperature of an ectotherm varies significantly with<br />environmental conditions.<br />Heat exchange<br />温 度 阈 高温可能导致酶失活或代谢组分不平衡，例如植物的<br />呼吸作用快于光合作用而导致死亡。然而高温对外温<br />动物最普遍的影响是引起脱水。所有陆生外温动物必<br />须保持水，但在高温下失水率能够成为致死因子。不<br />同物种对低温的耐受性有很大的差异，这与结冰、寒<br />冷和坚硬的过程有关。温度低于 -1℃ 时很多物种被冻死，<br />这是由于细胞内冰晶形成的损伤效应；那些生活在整<br />个冰冻冬天的种，经常是处于一种有抵抗力的休眠时<br />期，这是它们生命周期中的一个阶段。<br />相关题目 太阳辐射与气候（ C1） 对温度的响应（ E2）<br />植物与水（ D2） 温度与物种分布（ E3）<br />动物与水（ D3） 生态系统格局（ S1）<br />High temperatures may lead to enzyme inactivation or the<br />unbalancing of components of metabolism; for example,in<br />plants,respiration may proceed faster than photosynthesis,<br />leading to death,however,the most frequent effect of high<br />temperature on ectotherms is dehydration,All terrestrial<br />ectotherms must conserve water but at high temperatures<br />rates of water loss can be lethal,There are large differences<br />between the low temperature tolerances of differing species,<br />associated with the processes of freezing,chilling and<br />hardening,Many are killed by temperatures below –1℃<br />due to the damaging effects of ice-crystal formation within<br />cells; those that live through freezing winters often do so at<br />a resistant,dormant stage of their life cycle.<br />Temperature<br />thresholds<br />Related topics Solar radiation and climate(C1) Responses to temperature<br />(E2)<br />Plants and water (D2) Temperature and species<br />Animals and water (D3) distribution (E3)<br />Ecosystem patterns (S1)<br />E2 对温度的响应<br />要 点<br />温度和酶反应<br />速度<br />酶催化反应的速度随温度而增加。在外温动物中这意<br />味着在较高的温度中代谢活力更快。温度系数（ Q 10)<br />是温度升高 10℃ 对代谢速度影响的指数，经常大约为<br />2.0。<br />发育和生长的<br />速度<br />在非致死温度范围内，温度对外温动物最大的影响很<br />可能是影响了发育和生长的速度。当用发育速度对体<br />温做图时，存在着一个直线相关的温度范围。“生理<br />时间”是将温度和时间相结合的一个测量，应用于外<br />温动物，它反应了这些有机体的生长和发育依赖于温<br />度及时间。<br />The rate of an enzyme catalyzed reaction increases with temperature,<br />In ectotherms this means that metabolic activity will be faster at<br />higher environmental temperatures,The temperature coefficient (Q10)<br />is an indexof the effect of a 10℃ temperature rise on metabolic rate,<br />and is often near 2.0,<br />Key Notes<br />Within the nonlethal temperature range the most important effect<br />on ectotherms of temperature is likely to be its effect on rate of<br />development and growth,When rate of development is plotted<br />against body temperature there exists an extended range of<br />temperatures over which the relationship is linear,?Physiological<br />time‘ is a measurement combining temperature and time and<br />applied to ectothermic organisms,which reflects that growth and<br />development of these organisms is dependent on environmental<br />temperature as well as time.<br />Temperature and<br />rates of enzyme<br />reaction<br />Rates of development<br />and growth<br />E2 RESPONSES TO TEMPERATURE<br />驯化和气候<br />驯化<br />温度能够作为一种刺激物起作用，决定有机体是否将<br />开始发育。春化法是通过低温诱导开花。有机体在实<br />验室里暴露到较高（或较低）的温度能够改变有机体<br />的温度反应。有机体对实验环境条件变化产生的适应<br />性反应称为 驯化 （ acclimation）。有机体对自然环境条<br />件变化产生的生理适应性反应称为 气候驯化<br />（ acclimatization）。<br />相关主题 太阳辐射与气候（ C1） 温度与物种分布（ E3）<br />温度与代谢（ E1） 生态系统格局（ S1）<br />Temperature may also act as a stimulus,determining whether the<br />organisms will begin development,Vernalization is the induction<br />of flowering by low temperatures,Exposure of an organism to<br />higher (or lower) temperatuers in the laboratory can alter the<br />organisms temperature response,The habituation of an organism‘s<br />response to changes in laboratory environmental conditions is<br />termed acclimation,Acclimatization is the habituation of an<br />organism‘s physiological response to changes in natural<br />environmental conditions.<br />Acclimation and<br />acclimatization<br />Related topics Solar radiation and climate(C1) Responses to temperature (E2)<br />Plants and water (D2) Temperature and species<br />Temperature and metabolism (E1) distribution (E3)<br />Ecosystem patterns (S1)<br />The rate of photosynthesis is a gross measurement of the rate at<br />which a plant captures radiant energy and fixes it into carbon<br />compounds,Net assimilation is the difference between<br />photosynthetic assimilation and losses due to respiration,<br />Therefore,net assimilation will be negative in the dark and will<br />increase with increasing PAR,The intensity of PAR at which the<br />gain in photosynthesis equals the losses is known as the<br />compensation point.<br />Measurement of<br />photosynthesis<br />E3 温度与物种分布<br />要 点<br />物种分布与<br />温度<br />地球上主要生物群系的分布反应了主要的温度带。然<br />而当考虑物种分布的时候，很难归结于温度的作用。<br />在某些情况下，一个物种的分布界限能够归结于阻止<br />物种生存的致死温度。然而，种的分布限与等温线间<br />相一致，是一种更广泛分布的相关类型。等温线是在<br />地图上把具有相同平均温度的地方连结起来的线。总<br />的说来，一个有机体的分布界限不是由致死温度所决<br />定，而是由造成竞争强弱条件所决定。<br />The distribution of the major biomes over the Earth reflects the major<br />temperature zones,However,it is more difficult to attribute a role to<br />temperature when considering species distribution,In certain cases<br />the distribution limits of a species can be attributed to a lethal<br />temperature which precludes the species‘ existence,However,a more<br />widespread type of relationship is one which has a correspondence<br />between the distribution limits of a species and an isotherm,An<br />isotherm is a line on a map that joins locations having the same mean<br />temperatures,Overall,an organism‘s limit to distribution is<br />determined not by lethal temperatures,but by conditions that make it<br />a poor competitor,<br />Key Notes<br />Species distribution<br />and temperature<br />E3 TEMPERATURE AND SPECIES<br />DISTERIBUTION<br />对温度的进化<br />反应<br />温度对个体的影响被进化的变异减弱。阿伦法则<br />（ Allen‘s rule）陈述了来自冷气候中的内温动物与来自<br />温暖气候的内温动物相比，趋向于具有更短的末端<br />（耳朵和四肢）；因此降低了它们的表面积对体积的<br />比率。这个规律有很广的适用性。贝格曼规律<br />（ Bergmann‘s rule）讲述了寒冷地区的哺乳动物比温暖<br />地区的哺乳动物个体趋向于更大，也减低了它们的表<br />面积与体积的比率。这个规律没有广泛的种间的适用<br />性，是由于在测定体重中牵涉到其它的重要因子，但<br />是在种内经常是真实的。<br />相关主题 温度与代谢（ E1） 竞争的性质（ I1）<br />对温度的响应（ E2） 生态系统格局（ S1）<br />The effects of temperature on individuals may be moderated by<br />evolved differences,Allen‘s rule states that endothermic animals<br />from cold climates tend to have shorter extremities (ears and legs)<br />compared with animals from warmer climates,thus reducing their<br />surface area,volume ratio,This rule has widespread applicability,<br />Bergmann‘s rule states that mammals tend to be larger in colder<br />areas than warm climates,again to reduce their surface area,<br />volume ratio,This rule does not have widespread interspecific<br />applicability due to other important factors involved in<br />determining body weight,but is often true intraspecifically.<br />Evolved response to<br />temperature<br />Related topics Temperature and metabolism (E1) The nature of competition (I1)Responses to temperature (E2) Ecosystem patterns (S1)<br />F1 太阳辐射与植物<br />要 点<br />辐射能和光合<br />作用<br />绿色植物能够利用的惟一能源是辐射能。当叶子截获<br />辐射能时，它能被吸收、反射或者透射。吸收的部分<br />能量到达叶绿体，引发了光合作用，在这个过程中，<br />辐射能被用于转化水和二氧化碳成为糖。太阳辐射包<br />含了不同波长的光谱。然而，仅有一个有限的光谱带<br />对光合作用是有效的。这就是光合活性辐射（ PAR）带，<br />对绿化植物是位于 380nm到 700nm之间。<br />F1 SOLAR RADIATION AND<br />PLANTS<br />Radiant energy is the sole energy source that can be<br />used by green plants,When a leaf intercepts radiant<br />energy it may be absorbed,reflected or transmitted,<br />Part of the fraction absorbed reaches the chloroplast,<br />fuelling photosynthesis,the process where radiant<br />energy is used to convert water and CO2 into sugars,<br />Solar radiation contains a spectrum of different<br />wavelengths,However,only a restricted band of this<br />spectrum is effective for photosynthesis,This is the<br />band of photosynthetically active radiation (PAR)<br />and for green plants lies between 380 and 710 nm..<br />Key Notes<br />Radiant energy and<br />photosynthesis<br />辐射能转换<br />效率<br />计算光合作用效率是有可能的。作为生物化学过程，<br />光合作用是高效率的；进入反应部位的可用辐射能的<br />35%转化为潜在能量。在植物水平上的真实效率在<br />0.5%和 3%之间变化，取决于植物和环境。<br />C3和 C4植物 植物光合能力中的主要差别是在 C3和 C4植物之间。 C4<br />植物能捕获 CO2,伴随着水的利用效率比 C3植物更大，<br />而这优点需要消耗能量。在 C4植物中，光合作用率随<br />光强度而增加，而 C3植物随光强度增加光合作用渐渐<br />减小。<br />It is possible to calculate the efficiency of<br />photosynthesis,As a biochemical process<br />photosynthesis is efficient; 35% of usable4 radiant<br />energy entering a reaction site is converted to<br />potential energy,The actual efficiency at the plant<br />level varies between 0.5% and 3.0%,depending on<br />the plant and the environment.<br />Efficiency of radiant<br />energy conversion<br />A major difference in the photosynthetic capacity of<br />plants is that between C3and C4 plants,C4 plants are<br />able to capture CO2 with greater water use efficiency<br />than C3 plants,but this advantage comes at an energy<br />cost,In C4 plants the rate of photosynthesis increases<br />with light intensity,whilst photosynthesis tails off<br />with increasing light intensity in C3 plants,<br />C3 and C4 plants<br />辐射强度的<br />变化<br />植物很难获得它们完全的光合作用潜能，是由于水短<br />缺和辐射强度的改变。光强度的系统变化是太阳辐射<br />的日节律和年节律。光强度中极少部分的系统变化是<br />因叶子彼此的相对位置引起。<br />植物对辐射的<br />战略和战术<br />响应<br />植物种间对辐射强度反应的主要战略差异显示为“阳<br />地种”和“阴地种”，它们分别具有适应于高的和低<br />的光辐射范围。同样，植物能够在不同光条件下生长<br />不同的叶子，作为对光环境的部分战术反应。这一点<br />最清楚地在单株植物叶冠内的阳叶和阴叶的结构上看<br />到。<br />Plants rarely achieve their full photosynthetic potential,<br />due to water shortage and to variation in the intensity<br />of radiation,The systematic variations in light<br />intensity are the diurnal and annual rhythms of solar<br />radiation,Less systematic variations in light intensity<br />are caused by the posit