生态学课件_生态学

that remove nutrients from the system. Release may
be direct to the atmosphere or via bacterial action (as in the case of methane). For many elements, the most
Habitat
Multidimensional niche space
基础生态位
在没竞争和捕食条件下，有机体的生态位空间叫做基 础生态位（fundamental niche）。
实际生态位
当有竞争和捕食出现时，有机体所占有的生态位空间 是实际生态位（realized niche），实际生态位始终是基 础生态位的一个子集。
Realized niche
Related topics
The nature of competition (11) partitioning(13)
Resource
Intraspecific competition (12)
G1 资源与循环
要 点
群落以形形色色的方式获得和损失营养物。机械风化、 化学腐蚀，特别是碳酸化作用，都是重要的过程。矿
Nutrient sources
AND CYCLES
Nutrients are gained and lost by communities in a variety of ways. Mechanical weathering, chemical weathering, particularly carbonation, are important processes. Simple dissolution of minerals in water also makes nutrients available from rock and soil. Water may carry nutrients in watercourses providing an important source in downstream areas. Atmospheric gases provide nutrient sources too, particularly carbon dioxide and nitrogen. Other nutrients from the atmosphere become available to communities as wetfall (rain, snow and fog) and dryfall (settling of particles during dry periods).
生 态 位
栖 息 地
多维生态位空间
B3 THE NICHE
Key Notes
Niche The ecological niche of an organism is the position it fills in its environment, comprising the conditions under which it is found, the resources it utilizes and the time it occurs there. The habitat of an organism is the physical environment it is found in, for example, a temperate broad-leaved woodland. Each habitat provides. Each condition or resource which defines the niche of an organism contributes one dimension to the space in which the organism’s niche, and is the multidimensional niche space, or’n-dimensional hypervolume’.
学。
Geochemistry
The pools of chemical elements on earth exist in
various compartments: in rocks (the lithosphere),
and soil water, streams, lakes or oceans (whish, combined, constitute the hydrosphere). In all these cases, the chemical elements exist in the inorganic form. In contrast, living organisms and dead and decaying organic matter are compartments which contain elements in the organic form. Studies of the chemical processes occurring within these compartments and the flux of elements between them (which are fundamentally altered and affected by biotic processes) is termed
contain warm suface waters, where most plant life is
found and cold deep waters (which make up 90% of the total water volume). Nutrients in the suraface waters come from two sources: (i) upwelling from deep water (which comprise over 95% of the nutrient budget),and (ii) river input.
water is a major factor. Commonly, phases of fast
inorganic nutrient displacement alternate with periods when the nutrient is locked in biomass. In lakes, plankton play a key role in nutrient cycling. Oceans
B3 生 态 位Байду номын сангаас
要 点
有机体的生态位（niche）是它在它的环境中所处的位 置，包括它发现的各种条件、所利用的资源和在那里 的时间。 有机体的栖息地（habitat，或译生境）是它所处的物理 环境，例如，温带阔叶林。每一个栖息地提供许多生 态位。 定义有机体生态位的每一个条件和资源，对于有机体 能出现的空间提供一个维度。一起考虑所有维度，全 面确定的有机体的生态位，是多维生态位空间，或“n维超体积”。
biogeochemistry.
全球生物地化 循环
陆地植物利用空气中CO2作为光合作用的碳源，而水生 植物使用溶解的碳酸化合物（水圈的碳）。呼吸作用 把固定在光合产物中的碳，再释放到气圈和水圈的碳
圈层中。在全球氮循环中，气相是占优势的，其中，
氮的固定和微生物的脱氮作用特别重要。磷主要储存 在土壤水、河流、湖泊、岩石和海洋沉淀物中，而硫 储存在大气和岩石的组分中。
相关主题
竞争的性质（见I1） 种内竞争（见I2）
资源分配（见I3）
Fundamental niche
The niche space an organism can fill in the absence of
competition or predation is known as the fundamental niche. The niche space occupied by an organism when competition and predation occur is the realized niche, which is always a subset of the fundamental niche.
陆地群落营 养物预算
有机体吸收的特定营养物微粒可连续地循环，直到营 养物最终损失，这是通过许多过程中的任一个过程把 营养物从系统中除去。营养物释放可直接到达空气或 通过细菌作用（如甲烷）。对于许多元素来说，最重 要的是丢失途径是在水流中。营养物损失的其他途径 包括火灾、庄稼的收获和森林砍伐。
Nutrient budgets in terrestrial communities
Nutrient budgets in aquatic communities
Aquatic systems obtain the bulk of their supply of nutrients from streamflow. In streams, rivers and lakes with a stream outflow, export in outgoing stream
地球化学
地球上的化学元素库存在于各种圈层（compartments） 中：在岩石（岩圈）和土壤水、溪流、湖泊或海洋 （可组合构成水圈）中。在上述情况下，化学元素以 无机形式存在。同时，生命有机体和已死亡及腐烂的 有机物质是在含有有机元素的圈层里。研究在这些区 域内发生的化学过程和圈层间元素的流动（通过生物 过程产生了功能性的改变和影响），称为生物地球化
A particular nutrient atom taken up by an organism may cycle continuously until eventually the nutrient will be lost through any one of a number of processes