Global Change and Southern California Ecosystems Rebecca Aicher UCI GK-12 March 7, 2009

What is global change? / Humans alterations of biological diversity, land cover, atmospheric composition, and the climate system.

Global Change Ecology Study of how these alterations influence the complex web of interactions among species, ecosystem processes and the Earth as a whole.

Global Change in Southern California Ecosystems DroughtsInvasive Species Nitrogen fertilizationIncreased fire frequency

How Does Global Change Affect Coastal Sage Scrub Communities? Across the state, only 10% of coastal sage scrub habitat remains Animal species rely on CSS habitat

Coastal Sage Scrub Species Decline as Invasive Species Increase Over Time Talluto and Suding s 2005 Vegetation Cover in Annual Grassland Communities and Coastal Sage Scrub Communities Coastal sage scrub Annual grasses and forbs

Interactive Factors Facilitate Success of Non-native Annual Grasses Increases in fire frequency Air pollution and nitrogen deposition Talluto and Suding 2008

Studying Global Change Ecology in High School Biology Classes How does nitrogen fertilization affect diversity in coastal sage scrub communities? Does nitrogen fertilization increase the invasibility of coastal sage scrub communities?

What Global Change Factors Affect Native Perennial Grasslands? Less than 1% of native grasslands remain and hypothesized due to: –Extreme drought in the late 1800s –Cattle grazing –Introduction of invasive species from regions with similar climates –Nitrogen deposition –Land use change –Interaction of all of these factors leads to non- native annual dominated communities

Southern California Grasslands Dominated by non-native annual grass species with relict native perennial grasses and native annual forbs Non-native Native Site Burned in Fall 2007

Studying Global Change Ecology in the Field to Restore Native Grasslands

How Do Nitrogen Fertilization, Dispersal, and Dominant Species Determine Grassland Composition? Dispersal Nitrogen Plots Dispersal Control Plots No Dispersal Control Plots No Dispersal Nitrogen Plots Lupine Dominant Amsinckia Dominant

Pollination, Flower Morphology, and Abundance Today in the field you will: monitor pollinator visitation use a dichotomous key to identify pollinator syndromes measure abundance and height of two dominant species extract nematodes from the soil seed an experimental grassland