yi森林生态学-3-森林生态系统的能量流动 - 图文

Chapter 2 The energy transfer of Ecosystems 生态系统的能量流动1. About energy concept 关于能量的概念2. Where is energy from? 能量的来源3. The trophic structures of ecosystems 生态系统的能量结构4. Ecological Energetics: Energy Dynamics and Storage in Ecosystems 生态系统的能量流动与储存1. About energy concept 关于能量的概念

Energyis what life is all about, and

everything about life is associatedwith energy. Organisms are

accumulations of energy, without a

continuing supply of energy they die, and the energy accumulation is dispersed as their remains decompose. All organisms require a source of energy they must do work, and to do work they must expend energy.

?为什么要研究生态系统的能量流动？??

能量是生态系统的驱动力

林业、农业、渔业、牧业等工作者对森林、农田、渔场、草原等的经营管理，应掌握能量的输入和输出途径及其限制因素，以达到高产目的，设法调整生态系统的能量分配关系，使能量流向对人类最有益的部分。

能量Energy——做功的能力(work)。

calorie或千卡Great calorie。

1)2) 能量值的表示：卡

3) 与生物体有关的几种能量形式：

Types of Energy:

Mechanic 机械能Chemical 化学能

Radiation 辐射能

Heat 热能

4) Ecological Energetics生态能量学The study of energy relationships (input, storage, transfer and outputs) of ecosystems is called.5 ) 生态系统能量流遵循热力学定律(1) 热力学第一定律又称为能量守恒与转化原理Thermodynamics First law: Energy Equilibrium Law or Energy Conservation Law

能量可从一种形式转换成另一种形式，但能量即不能增加也不会减少。

如太阳辐射能，通过绿色植物的光合作用转变为存在于有机物质化学键中的化学潜能；动物通过消耗自身体内贮存的化学潜能变成爬、跳、飞、游的机械能

(2) 热力学第二定律(Second Law: Energy Consuming or 熵律entropy law)

表达有关能量传递方向和转换效率的规律。

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自然界中任何形式的能最终归宿是热能，且不可逆。?任何一种能量的转换，总有一些能量损失掉，一种形式的能绝不会全部转换成另一种形式的能。

热力学的两个定律First law：A = B + CSecond law ：C < AA: light 日光，100单位释放

B: 热heat，98单位释放的能量

形式(98% loss)

的能量

C:糖carbohydrate单位

，SUN浓缩的能量形式橡树叶能量转换系统

energy transfer in oak leaf

2

energy transfer in ecosystems 生态系统中能量的流动radiation热能Heat化学能Chemical热能Heat机械能Mechanical太阳辐射能有机物质的合成过程，即生产者（绿色植物）吸收太阳能量形成初级生产量。活有机物质被各级消费者（动物）消费的过程。死有机物质（动植物残体和排泄物）被腐生物分解的过程。能量流动特点：

1. less and less “越流越细”，能量在流动过程中逐渐耗散。2 One way 单向流动，不可逆。

生態系能量流?太陽能被生產者利用僅約1%?能量在各階層間的轉化效率平均在10%左右?流經碎屑食物鏈的能量相當大Ecosystem2. Where is energy from? 能量的来源

?我们能利用的能量来自：太阳辐射、核能、地?

热……

太阳辐射能是生态系统中的能量的最主要来源。In ecosystems the sources of energy supply :

Autotrophs (自养生物)Heterotrophs (异养生物)

Radiation 太阳辐射radiationWireless waves 无线电波infrared红外线Visible 可见光ultraviolet radiation紫外光X-light ray射线rayWavelength 波长Frequency 频率/秒1041010.1101510-610101020The range of spectrumDuring photosynthesis, plants absorb carbon dioxide and sunlight to create fuel—glucose and other sugars—for building plant structures. This process forms the foundation of the biological carbon cycle. (Illustration courtesy P.J. Sellers et al.)

In the sources of energy 按能量来源将生物分为：光能自养型(photoautotrophs)

1) Autotrophs自养生物化能自养型(chemoautotrophs)

Called self-feeding organisms, or Producer or Primary producer

?Sun-original source of energy.

Captured by autotrophs {from latin, self-food}, that's plants, the primary producers. The energy is stored as food, which drives the heterotrophs {latin, different-food}, the consumers.

2) Heterotrophs 异养生物?Herbivores(草食动物)?Carnivores(肉食动物)?Omnivores(杂食动物)?Saprotrophs)(腐生物) -(Decomposer)

Consumers

?In an ecosystem, the organisms composing the

populations and communities all require energy for survival. That energy can come from the sun in the case of the plants, or from food, in the case of the animals. The original source of energy in most ecosystems is the sun; the plants use the light for photosynthesis, which converts the light energy into basic sugars, which the plant uses as its food and stores in the form of sugars, starches, and other plant material. The animals derive all of their energy from the energy from plants stored in their bodies. The animals are divided into

different trophic levels depending on if they eats the plants for their energy supply, if they eat the animals that ate the plants, or if they eat the animals that ate the animals that ate the plants.

3. Trophic structures or levels of ecosystems 生态系统的能量结构

3.1 Food Chains 食物链A ecosystem looks inordinance. Actually, all components are interconnected orderly through the food relationships, thus form chain structure, called food chain or trophic chain

For example: Silkworm-Mantis-yellowbird指生物界食物关系中，甲吃乙、乙吃丙、丙吃丁的现象。生物之间这种能量转换连续依赖的次序称为食物链。

?Trophic Levels Producers-the plants storing the

energy as food. Herbivores-the animals which eat the plants. i.e., Cows, Parrotfish, Humans. Carnivores-the animals which eat the animals which ate the plants. i.e., Coyotes, Barracuda, Humans. Second Level Carnivores-the animals which ate the first level carnivores. i.e., Bears, Sharks, Humans. Third Level Carnivores-very rare Fourth Level Carnivores-some do exist Decomposers-break down the complex organic molecules of dead organisms from all trophic levels. Mostly Bacteria, also Hagfish, funguses, etc.

3.1.1 The types of food chain 食物链类型：1) Grazing Trophic Chain:The energy transfers from

Autotroph—Herbivores—Carnivores, are referred to as草牧食物链（捕食食物链）: 是以绿色植物为基础，从草食动物开始的食物链，草原和水体生态系统是以草牧食物链为主的生态系统。

2) Decomposer or Detritus Trophic Chain : Trophic chains commencing with dead organic matter and involving saprotrophs are referred to as

?腐生食物链（碎食食物链）: 指以死有机物质为基础，从腐生物开始的食物链。森林是以腐生食物链为优势的生态系统。在森林中，有90%的净生产是被腐生生物所分解消耗的。

3) Parasitical food chain寄生性食物链:

由宿主和寄生物构成。它以大型动物为食物链的起点，继之以小型动物、微型动物、细菌和病毒。后者与前者是寄生性关系。

在生态系统中各类食物链具有以下特点：

?在同一个食物链中，常包含有食性和其它生活习性极

?

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不相同的多种生物。

在同一个生态系统中，可能有多条食物链，它们的长短不同，营养级数目不等。由于在一系列取食与被取食的过程中，每一次转化都将有大量化学能变为热能消散。因此，自然生态系统中营养级的数目是有限的。在不同的生态系统中，各类食物链的比重不同.在任一生态系统中，各类食物链总是协同起作用。食物链是生态系统能量流动的途径.

?In communities worldwide, the same

trophic levels exist. The species constituting each level differs

geographically, and in some areas each level may have a greater or fewer number of species constituting that level.

Ecologically equivalent species replace each other geographically, the species structure is variable. The trophic structure, in contrast, is a constant.

3.2 Trophic Web or Food Web 食物网Trophic Web or Food Web:

Ecosystems are complex systems. Most

plants are fed on by a variety of Herbivores and most herbivores feed on a variety of plants. Most herbivores are also fed on by a variety of carnivores.

Thus trophic chains are but components of an intricate network or web of trophic dependencies----

?生物之间的捕食和被食的关系不是简单的一

条链，而是错综复杂的相互依赖的网状结构，即食物网。

?食物网不仅维持着生态系统的相对平衡，并

推动着生物的进化，成为自然界发展演变的动力。

?这种以营养为纽带，把生物与环境、生物与

生物紧密联系起来的结构，称为生态系统的营养结构。

Food webs 食物网

3.3 Trophic Structure 营养级Trophic level is composed of organisms which have same food of Food Chain.

捕食食物鏈

碎屑食物鏈

Detritus Chain----Decomposition

?Detritusand animal matter

: fresh to partly decomposed plant

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?Fungal and microbial decomposition: Very

important, and works mostly off of the results of fragmentation.

?Detritivory: animals feeding off of dead OM

(detritus). Such animals include mites, nematodes, earthworms, sowbugs, several insect species, as well as fungus and bacteria.

3.4 Ecological Pyramid 生态金字塔Ecological or food chain efficiency,

Linderman 1942. (1935 Tansley firstly given a word Ecosystem)

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