Questão 12 - UEA - SIS 2ª Etapa 2016

Leia o texto para responder à questão.

 

Rare animals vital for ecosystem life support

  Rare animal species are vital to maintaining tropical ecosystems and could cause a chain reaction of disastrous biodiversity loss if they go extinct, a study warns.

  Animals that are considered rare – because they occupy a niche environment or there are few of them – are more likely than common animals to perform specialised and often irreplaceable roles in their environments, the study found. This is especially true for highly biodiverse environments, such as the tropics, the researchers say. “Losing rare species today may mean losing much more complex processes in the long term,” says lead author Rafael Leitão, a biologist at the National Institute of Amazonian Research in Manaus, Brazil.

  The study notes that rare animals perform essential “ecosystem services” such as dispersing seeds, filtering water and controlling other animal populations and invasive species. “There is no way to know exactly how, in future, an ecosystem     11     with the loss of those rare species, but chain effects are common, meaning that the loss of some functions can lead to other losses, making the whole environment crumble,” says Leitão.

(www.scidev.net. Adaptado.)

No trecho do terceiro parágrafo do texto “the loss of some functions can lead to other losses”, o termo em destaque pode ser substituído, sem alteração de sentido, por