暨大本科生態(tài)學(xué)課件General Ecology 10-3

1、段舜山 2009-12-8,1,主講教師: 段舜山 暨南大學(xué)生命科學(xué)技術(shù)學(xué)院生態(tài)學(xué)系 tssduan,生態(tài)學(xué)專業(yè)必修課 普通生態(tài)學(xué) GENERAL ECOLOGY,段舜山 2009-12-8,2,第10章,生態(tài)系統(tǒng) Ecosystems,段舜山 2009-12-8,3,第3節(jié) 水循環(huán)(復(fù)習(xí)),Concepts: Process of hydrologic cycle 水循環(huán)的過程 Characters of hydrologic cycle 水循環(huán)特征 Water is vital for ecosystems 水的生態(tài)作用 Seepage and runoff of water 滲流和徑流

2、An experiment of mineral loss 礦質(zhì)流失實驗 An experiment of calcium loss 鈣流失實驗,段舜山 2009-12-8,4,第4節(jié) 碳循環(huán)(復(fù)習(xí)),Concepts: Definition of carbon cycle 碳循環(huán)的定義 Process of carbon cycle 碳循環(huán)的過程 Characteristics of carbon cycle 碳循環(huán)的特征 Decomposition and accumulation 分解與積累 Earths carbon balance 地球碳平衡 Human impact on carb

3、on cycle 人類影響 Increase of carbon dioxide 二氧化碳增加 Effects of global warming 全球變暖效應(yīng),段舜山 2009-12-8,5,主要內(nèi)容,10.5 Nitrogen cycle 氮循環(huán) 10.6 Phosphorus cycle 磷循環(huán),段舜山 2009-12-8,6,第5節(jié) 氮循環(huán),Concepts: Definition of nitrogen cycle 氮循環(huán)的定義 Characteristics of N-cycle 氮循環(huán)的特征 N-fixation by microorganisms 生物固氮 Assimilati

4、on of nitrogen 氮素的同化作用 Ammonification and nitrification 氨化和硝化 Denitrification 反硝化作用 Fertilizers of nitrogen 氮素化肥的作用,段舜山 2009-12-8,7,Since the time of lifes origin, the atmosphere and oceans have contained nitrogen. This component of all proteins and nucleic acids moves in an atmospheric cycle called

5、 the nitrogen cycle. 指N在大氣中的循環(huán)運動,1. Definition of nitrogen cycle 氮循環(huán)的定義,段舜山 2009-12-8,8,2. Characteristics of N-cycle 氮循環(huán)的特征,Gaseous nitrogen (N2) makes up about 80 percent of the atmosphere, the largest nitrogen reservoir. But triple covalent bonds (NN) hold the two atoms in gaseous nitrogen togeth

6、er, and few organisms can break them.,段舜山 2009-12-8,9,Only certain bacteria, lightning, and volcanic action can convert N2 into forms that enter food webs. 某些細(xì)菌、閃電和火山作用可轉(zhuǎn)化氮氣為進(jìn)入食物網(wǎng) For this reason, nitrogen is often a limiting factor in ecosystems.,2. Characteristics of N-cycle 氮循環(huán)的特征,段舜山 2009-12-8,1

7、0,3. N-fixation by microorganisms 生物固氮,The conversion of gaseous nitrogen to forms that are useful to plants ammonia氨(NH3) and ammonium銨(NH4+) is carried out primarily by microorganisms (Figure 1). 從氣態(tài)氮到植物可利用的氨態(tài)氮的轉(zhuǎn)化過程主要是由微生物來完成的。,段舜山 2009-12-8,11,藍(lán)藻,豆科植物(感染根瘤菌)根瘤橫切面,Figure 1 固氮藍(lán)藻和根瘤菌,段舜山 2009-12-8,1

8、2,Plants assimilate and use this nitrogen in the biosynthesis of amino acids, proteins, and nucleic acids.植物吸收利用氮用于生物合成氨基酸、蛋白質(zhì)和核酸。 Plants tissues serve as the only nitrogen source for animals, which feed directly or indirectly on plants. 植物組織作為動物的唯一氮源，動物都是直接或間接取食植物獲得氮。See Figure 2.,4. Assimilation o

9、f nitrogen 氮素的同化作用,段舜山 2009-12-8,13,Figure 2 動物通過攝食植物或其它動物獲得氮源,段舜山 2009-12-8,14,Decomposition and ammonification 分解和氨化,Through decomposition and ammonification, decomposers break down nitrogencontaining wastes and remains of organisms. See Figure 3.,段舜山 2009-12-8,15,Figure 3 分解者對含氮動植物殘體和排泄物的分解作用,段舜山

10、 2009-12-8,16,5. Ammonification and nitrification 氨化和硝化,Ammonifying bacteria(氨化細(xì)菌)convert nitrogenous wastes and the nitrogenous residues released by the decomposers (把分解者釋放出來的含氮有機物轉(zhuǎn)化成)into ammonia or ammonium,which plants can take up. Nitrifying bacteria (硝化細(xì)菌) also act on ammonia or ammonium. 硝化細(xì)菌

11、同樣也作用于氨或銨鹽。 In nitrification, they strip these compounds of electrons, producing nitrite.在硝化作用中,它們脫去這些化合物(氨和銨鹽)的電子, 形成亞硝酸鹽,段舜山 2009-12-8,17,Other bacteria use the nitrite(亞硝酸鹽)in metabolism and produce nitrate(硝酸鹽), which plants take up. Also, some nitrogen is lost to the air by denitrification. Her

12、e, bacteria convert nitrate or nitrite to gaseous nitrogen and a bit of nitrous oxide(氮氧化物). The entire nitrogen cycle is shown in Figure 4.,6. Denitrification 反硝化作用,段舜山 2009-12-8,18,Figure 4 The nitrogen cycle 氮循環(huán)的過程,段舜山 2009-12-8,19,Why is nitrogen so often a limiting factor for land plants? The a

13、mmonium, nitrite, and nitrate that form during the cycle are highly vulnerable to leaching and runoff.氨態(tài)硝態(tài)亞硝態(tài)氮均極容易被淋溶和流失 Some nitrogen is lost to the air by denitrification. Nitrogen fixation comes at high metabolic cost to plants that are mutualists with nitrogen fixers.,7. Nitrogen shortage 氮素短缺問題

14、,段舜山 2009-12-8,20,Humans are altering the cycling of nitrogen in natural ecosystems with nitrogen fertilizers. But we cannot get something for nothing. Fertilizer production requires huge amounts of energy from fossil fuels - not from free, unending sunlight.當(dāng)前的化肥合成需要消耗巨大的能量即化石燃料, 并不是來自免費的取自不盡的太陽能。,

15、8. Fertilizers of nitrogen 氮素化肥的作用,段舜山 2009-12-8,21,氮循環(huán)討論與小結(jié),Definition of nitrogen cycle 氮循環(huán)的定義 Characteristics of N-cycle 氮循環(huán)的特征 N-fixation by microorganisms 微生物固氮 Assimilation of nitrogen 氮素的同化作用 Ammonification and nitrification 氨化硝化作用 Denitrification 反硝化作用 Fertilizers of nitrogen 氮素化肥的作用,段舜山 200

16、9-12-8,22,第6節(jié) 磷循環(huán),Concepts: Definition of P-cycle 磷循環(huán)的定義 Characters of P-cycle 磷循環(huán)的特征 Process of P-cycle 磷循環(huán)的過程 Geochemical phase 地球化學(xué)循環(huán)階段 Ecosystem phase 生態(tài)系統(tǒng)循環(huán)階段 Phosphorus of organisms 生物有機體磷 Humans intervening 人類干預(yù) Harmful algal blooms (HABs) 有害藻華,JINAN UNIVERSITY,段舜山 2009-12-8,23,Phosphorus cyc

17、le: Movement of phosphorus from rock or soil through organism, then back to soil. 磷從巖石或土壤開始，通過生物體，再返回到土壤中的運動過程。,1. Definition of P-cycle 磷循環(huán)的定義,段舜山 2009-12-8,24,2. Characters of P-cycle 磷循環(huán)的特征,The phosphorus cycle is an example of a sedimentary cycle. 沉積性循環(huán) The earths curst is the main storehouse fo

18、r this mineral and for others, including calcium and potassium. 磷、鈣、鉀等是地殼為主要儲庫 In the phosphorus cycle, phosphorus moves from land to sediments in the seas and the back to the land. 陸地海底沉積物陸地,段舜山 2009-12-8,25,3. Process of phosphorus cycle 磷循環(huán)過程,Phosphorus is typically present in rock formations on

19、land, in the form of phosphates. Through the natural processes of weathering and erosion(風(fēng)化和侵蝕), phosphates enter rivers and streams, which eventually transport them to the ocean. (Figure 1),段舜山 2009-12-8,26,Figure 1. Movement of phosphates with water,段舜山 2009-12-8,27,4. Geochemical phase of P-cycle

20、 地化循環(huán)階段,There phosphorus accumulates with other minerals as insoluable deposits(不溶性沉積物). These insoluable deposits may lie in the ocean for millions of years. Where crustal plates collide(地殼板塊碰撞), part of the seafloor may be uplifted and drained.,段舜山 2009-12-8,28,The seafloor, with its mineral depos

21、its, thereby becomes exposed as new land surfaces. Over geologic time, weathering releases phosphates from the rocks, and the geochemical phase of the phosphorus cycle begins again (Figure 2).,4. Geochemical phase of P-cycle 地化循環(huán)階段,段舜山 2009-12-8,29,Figure 2,圖2. 磷素的地球化學(xué)循環(huán)階段,JINAN UNIVERSITY,段舜山 2009-

22、12-8,30,5.Ecosystem phase of P-cycle 生態(tài)系統(tǒng)階段,The ecosystem phase of the cycle is far more rapid. All living organisms require small amounts of phosphorus. It is a key component of ATP, NADPH(輔酶II), nucleic acids, and other compounds.,段舜山 2009-12-8,31,Plants have the metabolic means to take up dissolv

23、ed, ionized forms of phosphorus. Actually, plants do this so rapidly and efficiently that they often reduce soil concentrations of phosphorus to extremely low levels.,6. Phosphorus of organisms 生物磷,段舜山 2009-12-8,32,Redfield 比例: 106C16N1P A. C. Redfield (1958) 通過研究海洋浮游植物發(fā)現(xiàn), CNP = 106161。,磷往往是水生態(tài)系統(tǒng)的限制

24、因子,段舜山 2009-12-8,33,Phosphorus of organisms 動物磷,Herbivores obtain phosphorus by eating plants; carnivores get it by eating herbivores. Animals excrete waste products that contain phosphorus.,段舜山 2009-12-8,34,Decomposition of organic phosphorus,Phosphorus is also released to the soil by the decomposi

25、tion of organic matter. The plants then take up phosphorus and so recycle it rapidly within the ecosystem. (figure 3),段舜山 2009-12-8,35,圖3. 磷循環(huán)的生物地球化學(xué)全過程,JINAN UNIVERSITY,段舜山 2009-12-8,36,Humans intervene in the phosphorus cycle in two ways： First, we mine large quantities of phosphate rock for use i

26、n fertilizers and detergents(清潔劑). Second, we add excess phosphate to aquatic ecosystems through our use of fertilizers, phosphate-containing detergents, and discharges from municipal sewers(市政污水).,7. Humans intervening 人類干涉,段舜山 2009-12-8,37,8. Harmful algal blooms(HABs)有害藻華,An overabundance of phos

27、phate in an aquatic ecosystem can cause explosive growth of cyanobacteria, algae, or aquatic plants.引起藍(lán)藻或水生植物的爆發(fā)性生長。 When the plants or algae die, they decay and deplete the water of dissolved oxygen, killing any fish present. See Figure 4-9.,段舜山 2009-12-8,38,Figure 4,實驗: 添加碳氮磷的湖區(qū)發(fā)生了藻類水華(HABs),段舜山 2

28、009-12-8,39,圖5. 云南滇池持續(xù)發(fā)生藍(lán)藻藻華污染,段舜山 2009-12-8,40,2007年5月10日，江蘇無錫黿頭渚風(fēng)景區(qū)工作人員正在觀察藍(lán)藻情況。由于太湖水體富營養(yǎng)化加劇，加上當(dāng)時天氣持續(xù)高溫，降雨不多，太湖水體的自凈能力減弱，導(dǎo)致藍(lán)藻藻華大面積暴發(fā)。,圖6. 太湖水環(huán)境惡化 暴發(fā)大規(guī)模藍(lán)藻水華,段舜山 2009-12-8,41,圖7.太湖水源污染、藍(lán)藻暴發(fā)、居民飲水告急,Figure 7,段舜山 2009-12-8,42,2007年太湖爆發(fā)藍(lán)藻水華,藍(lán)藻是一類原始古老的單細(xì)胞浮游植物。在地球上出現(xiàn)于距今35億至33億年前，現(xiàn)在已知1500多種,分布十分廣泛，遍及世界各地,但

29、主要為淡水種。有少數(shù)可生活在60-85的溫泉中，,圖8. 太湖沿岸風(fēng)力堆積成的藍(lán)藻藻泥,在富營養(yǎng)化水體中，藍(lán)藻常于夏季大量繁殖，并在水面形成一層藍(lán)綠色具腥臭味的浮沫，稱為水華，加劇了水質(zhì)惡化，對魚類等水生動物，以及人畜均有較大危害，嚴(yán)重時會造成魚類及其它水生生物的窒息死亡。,段舜山 2009-12-8,43,圖9. 氮磷污染為水體富營養(yǎng)化的主要原因,段舜山 2009-12-8,44,磷循環(huán)討論與小結(jié),Definition of P-cycle 磷循環(huán)的定義 Characters of P-cycle 磷循環(huán)的特征 Process of P-cycle 磷循環(huán)的過程 Geochemical phase 地球化學(xué)循環(huán)階段 Ecosystem phase 生態(tài)系統(tǒng)循環(huán)階段 P