科科學人

Long-term relationships between ecological stability and biodiversity in Phanerozoic reefs

Wolfgang Kiessling

http://www.nature.com/nature/journal/v433/n7024/full/nature03152.html

Although the oceans cover 70% of the Earth's surface, our knowledge of biodiversity patterns in marine phytoplankton and zooplankton is very limited compared to that of the biodiversity of plants and herbivores in the terrestrial world. Here, we present biodiversity data for marine plankton assemblages from different areas of the world ocean. Similar to terrestrial vegetation, marine phytoplankton diversity is a unimodal function of phytoplankton biomass, with maximum diversity at intermediate levels of phytoplankton biomass and minimum diversity during massive blooms. Contrary to expectation, we did not find a relation between phytoplankton diversity and zooplankton diversity. Zooplankton diversity is a unimodal function of zooplankton biomass. Most strikingly, these marine biodiversity patterns show a worldwide consistency, despite obvious differences in environmental conditions of the various oceanographic regions. These findings may serve as a new benchmark in the search for global biodiversity patterns of plants and herbivores.

(http://www.cnr.cn/tupian/200809/W020080912356989005871.jpg)

不同物種為什麼能共存

（Time-share aids biodiversity）

瞭解遺傳多樣性在自然界是怎樣維持的是一個根本性的問題。現有理論所假設的種群動態過於簡單，儘管這些動態很少得到證據支援。例如，在海洋浮游生物生態學的核心就有一個矛盾：這麼多不同的物種是怎樣靠基本上是相同的一個資源庫共存的，而又沒有一種或另一種物種居於支配地位？用水蚤及其藻類獵物所做的精巧的實驗表明，答案在於競爭物種的生命階段的時間選擇上。每個物種都包括處於不同生命階段的個體群，它們在一年不同時間有不同需求和不同豐度。由於豐度的高峰和低谷很少趕在同一時間，所以生態系統中有足夠空間供所有物種共存。
（Letters, p. 410）
http://www.nature.com/nature/journal/v433/n7024/full/nature03152.html

(http://pic.big5.dbw.cn/0/01/04/97/1049784_384301.jpg)

底下三篇也很好玩

Global biodiversity patterns of marine phytoplankton and zooplankton
Xabier Irigoien, Jef Huisman & Roger P. Harris
http://www.nature.com/nature/journal/v429/n6994/full/nature02593.html

Marine ecology:  Different measures of biodiversity
John R. Dolan
http://www.nature.com/nature/journal/v433/n7024/full/nature03320.html

Marine ecology:  Different measures of biodiversity (Reply)
Xabier Irigoien, Jef Huisman & Roger P. Harris
http://www.nature.com/nature/journal/v433/n7024/full/nature03321.html