1、生物地理學(xué),氣候 陸生生態(tài)系,風(fēng) 地球循環(huán)系統(tǒng)的重要部份,地理生態(tài)學(xué),To do science is to search for patterns, not simply to accumulate facts, and to do the science of geographical ecology is to search for patterns of plant and animal life that can be put on a map.,氣候,Weather 任何時(shí)間地點(diǎn)的溫度,壓力,溼度,降水,日照,雲(yún)量,風(fēng)向,風(fēng)速等物理特性 Front 兩個(gè)具不同溫度與密度的氣團(tuán)的交界

2、,氣候,Warm Front 暖空氣密度較低,遇冷空氣上升凝結(jié)成雲(yún) ,逐漸厚實(shí)後雲(yún)層降低,釋放其濕氣時(shí)將飄小雨 Cold Front 冷空氣密度較高,於暖空氣下方呈楔形,被推擠向上的暖空氣凝結(jié)成大水滴,常有雷雨形成,氣候,Tornado 龍捲風(fēng) 於陸地上快速形成難以預(yù)測(cè) Tropical cyclone 熱帶暴風(fēng) 於海上長(zhǎng)期形成可追蹤其路徑與風(fēng)速 生成於大西洋稱(chēng)颶風(fēng),於太平洋稱(chēng)颱風(fēng),氣候,Climate 長(zhǎng)期的天氣狀況, 平均溫度與平均雨量為決定氣候的兩個(gè)重要因子,氣候,氣流與氣候 1.地表受熱不均 2.地球軸線(xiàn)(假想線(xiàn))為傾斜 3.地球自轉(zhuǎn) 4.太陽(yáng)能量的偶發(fā)性衝擊地球 5.空氣與水的特性,

3、洋流與氣候,溫室效應(yīng),Rain shadow effect,Sea and Land Breezes,地球的主要生態(tài)系,溫度雨量與生態(tài)系,溫度雨量與生態(tài)系,海拔緯度與生態(tài)系,世界主要沙漠分布,Two major bands: 30o N and 30o S. Occupy about 30% of earths land surface. Water loss exceeds precip. most of the year. Soil usually extremely low in organic matter. Plant cover ranges from sparse to abse

4、nt. Animal abundance low, but biodiversity may be relatively high. Strong behavioral adaptations. Human intrusion increasing.,人類(lèi)對(duì)沙漠的衝擊,世界主要草原分布,Tropical Savanna,Often occur immediately N / S of Rain Forests. Climate alternates between wet / dry seasons. Drought associated with dry season leads to dr

5、y conditions and subsequent lightning-caused wildfires. Soils have low water permeability. Saturated soils keeps trees out. Increasing pressure to produce livestock.,Temperate Grassland,Extremely widespread distribution. Annual rainfall 300 1,000 mm. Experience periodic droughts. Soils tend extremel

6、y nutrient rich and deep. Thoroughly dominated by herbaceous vegetation. Large roaming ungulates. Bison vs. cattle,Tundra,Covers most of lands N of Arctic Circle. Climate typically cool and dry with short summers. 200-600mm precip. Low decomposition rates. Supports substantial numbers of native mamm

7、als. Human intrusion historically low, but increasing as resources become scarce.,人類(lèi)對(duì)草原的衝擊,世界主要森林分布,Tropical Rainforests,Most occur within 10o lat. of equator. Little temp. variation between month. Annual rainfall 2,000 4,000 mm relatively evenly distributed. Heavy rainfall quickly leaches soil nutr

8、ients. Organisms add vertical dimension to ecology. Harbor staple foods and medicines for worlds human populations increasingly exploited.,Latitudinal Gradients in Species Richness,Most groups of organisms are more species-rich in the tropics. Brown grouped hypotheses into six categories: Time Since

9、 Perturbation More species in the tropics because tropics are older and disturbed less frequently. More time for speciation, and less frequent disturbance reduces extinction rate.,Latitudinal Gradients in Species Richness,Productivity High productivity contributes to high species richness. More ener

10、gy to divide among population. Environmental Heterogeneity More heterogeneity thus more potential habitat areas and niches.,Latitudinal Gradients in Species Richness,Favorableness Tropics have more favorable environments. No extremes to limit diversity. Niche Breadth and Interspecific Interactions V

11、arious themes Brown suggests that ultimate causes must by physical differences.,Latitudinal Gradients in Species Richness,Speciation and Extinction Rates Rosenzweig proposed immigration can be largely discounted at broad scales, thus speciation will be primary source of new species. Species removal

12、via extinction. Tropics richness is greater due to higher rates of speciation and/or lower rates of extinction.,Temperate Forest,Majority lie between 40o and 50o. Rainfall averages 650 3,000 mm. Fertile soils Long growing seasons dominated by deciduous plants. Short growing seasons dominated by coni

13、fers. Biomass production can be very high. Many major human population centers.,Boreal Forest (Taiga),Confined to N. hemisphere. Covers 11% of earths land area. Thin, acidic soils low in fertility. Generally dominated by evergreen conifers. Relatively high animal density. Historically, low levels of

14、 human intrusion.,人類(lèi)對(duì)森林的衝擊,Mountain Biomes,Make up almost a fourth of the worlds land surface. Contain the majority of the worlds forest. Regulate the earths climate when their snow- and ice-covered tops reflect solar radiation back into space. Play a critical role in the hydrological cycle.,人類(lèi)對(duì)山地的衝擊,Three Major Lessons,Different cli