enzh-TWfrderues

Bio­di­ver­sity


A Col­lec­tion of News by Moos


201323Feb14:56

Bio­di­ver­sity helps pro­tect Nature against human impacts

Infor­ma­tion
pub­lished 23 Feb­ru­ary 2013 | mod­i­fied 23 Feb­ru­ary 2013
Archived
Sagebrush-SlopesYou don’t know what you’ve got ‘til it’s col­lapsed.” That’s how Uni­ver­sity of Guelph inte­gra­tive biol­o­gists might recast a line from an iconic folk tune for their new research paper warn­ing about the per­ils of ecosys­tem break­down.

Their research, pub­lished online on Feb­ru­ary 6 in Nature, sug­gests farm­ers and resource man­agers should not rely on seem­ingly sta­ble but vul­ner­a­ble single-​crop mono­cul­tures. Instead they should encour­age more kinds of plants in fields and woods as a buffer against sud­den ecosys­tem disturbance.

Species are more impor­tant than we think. We need to pro­tect biodiversity.
Prof Andrew Mac­Dougall, co-​author, Depart­ment of Inte­gra­tive Biol­ogy, Uni­ver­sity of Guelph »


Based on a 10-​year study, the paper also lends sci­en­tific weight to esthetic and moral argu­ments for main­tain­ing species bio­di­ver­sity. The research con­firms that hav­ing lots of species in an area helps ecosys­tems avoid irre­versible col­lapse after human dis­tur­bances such as cli­mate change or pest inva­sion.

Unlike other sci­en­tists usu­ally rely­ing on short-​term, arti­fi­cial study plots, the researchers stud­ied long-​standing pas­ture grass­lands on south­ern Van­cou­ver Island for 10 years. The 10-​hectare site owned by the Nature Con­ser­vancy of Canada con­sists of oak savan­nah where fires have been sup­pressed for about 150 years.

The team selec­tively burned plots to com­pare areas of mostly grasses with areas of mixed grasses and diverse native plants. They found that seem­ingly sta­ble grass­land plots col­lapsed in one grow­ing sea­son and were sub­se­quently invaded by trees. More diverse sites resisted woody plant inva­sion.
Diver­sity also affected fire itself. More diverse areas had less per­sis­tent ground lit­ter, mak­ing high-​intensity fires less likely to recur than in single-​species grass­lands with more lit­ter serv­ing as fuel.

Mac­Dougall said the study sup­ports resource man­age­ment strate­gies that increase bio­di­ver­sity on land and in aquatic ecosys­tems. A mono­cul­ture stand of trees or crops might appear sta­ble and pro­duc­tive, for exam­ple — but it’s an ecosys­tem that is more vul­ner­a­ble to col­lapse, he said, adding that this study helps explain why species diver­sity mat­ters.

Co-​author Kevin McCann, who stud­ies food webs and ecosys­tem sta­bil­ity, said many ecosys­tems are at a “tip­ping point,” includ­ing grass­lands that may eas­ily become either wood­lands or deserts. “They’re a really pro­duc­tive ecosys­tem that pro­duces year in and year out and seems sta­ble and then sud­denly a major per­tur­ba­tion hap­pens, and all of that bio­di­ver­sity that was lost ear­lier is impor­tant now,” he said.


(Source: Uni­ver­sity of Guelph news release, 06.02.2013)
UN Biodiversity decade

Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

about zoos and their mis­sion regard­ing breed­ing endan­gered species, nature con­ser­va­tion, bio­di­ver­sity and edu­ca­tion, which of course relates to the evo­lu­tion of species.
Fol­low me on: