Envirothon Provincials

Invasive Species Characteristics

• Few natural enemies

• high reproductive rates

• high survival

• good dispersal

• aggressive competitors

The 4 pathways of introduction and spread

1. Transport

   1. Human activities

2. Introduction

   1. arival at new destination

3. Establishment

   1. production of a viable, self-sustaining population

4. Spread

   1. Dispersal and movement in a new region or range

Examples of Unintentional Introductions

Plant products

ballast

Tourism and recreation

Examples of intentional introductions

Biological control

agriculture

pet trades

Lag time

the time between a plants introduction and its discovery as an invasive specie

what are the 3 potential causes of a lag phase for plants

1. Low initial numbers

2. evolution

3. change in local environment

what can plant invaders alter

• ecological processes

  • fire regime, nutrient cycling, hydrology, and energy

• outcome native species

• soil degredation and erosion

What can invasive predators alter

cause changes through consuming prey species that drive ecosystems

hybridization

occurs when two different species mate with each other and produce viable offspring.

eg. eurasian watermilfoil (invasive) and northern watermilfoil hydridized