Invasives from altered gene pools atlantic smooth

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: than native cordgrass • Reduces tidal flow over saltmarsh Invasives from North America! Invasives from Altered gene pools Atlantic smooth cordgrass (Spartina alterniflora) hybridizes with native Pacific saltmarsh cordgrass (Spartina foliosa ) – Local populations eliminated as distinct species •n Spartina foliosa •n Spartina alterniflora •n Spartina hybrid Community Succession • Succession: The gradual change in community structure, composition and distribution over time, generally following a significant disturbance to the environment. • A disturbance is an event that changes a community – Removes organisms from a community – Alters resource availability North American pines invading grassland and riparian habitat in southern Brazil Heyer 15 Community Ecology Primary succession on moraines behind retreating glaciers • 1° succession is a change from a prebiotic to a biotic habitat following a catastrophic disturbance. 1899 1879 1879 1935 1949 1879 Johns Hopkins Gl. 1948 0 (a) Pioneer stage, with fireweed dominant 5 1 0 Miles 1941 1931 1911 1948 Gl. 1907 au te Pla Grand Canada Pacific Gl.Alaska 1940 1912 Gl. uir M • 2° succession is the gradual replacement of opportunistic species by more specialized competitors. • Stability is the end-product of succession when it is not interrupted by significant disturbances. • Pioneer commu...
View Full Document

This note was uploaded on 09/02/2011 for the course BIOL 6C taught by Professor Sundram during the Spring '09 term at DeAnza College.

Ask a homework question - tutors are online