Sedgwick Reserve

22 Mar, 03 AM - 23 Mar, 11 AM

Plant invasion have impacted nearly every ecosystem on Earth. One of the most dramatic and well documented invasions has been in California grassland communities. California grasslands have experienced a widespread conversion from perennial grass and annual forb-dominated lands to lands dominated by Mediterranean annual grasses and forbs. Currently it has been reported that this conversion has lead to impacts on nutrient cycles (water and nitrogen), but there has been no attempt to quantify how this conversion affects the diversity of plants or higher trophic levels. Sedgwick Reserve provides a unique opportunity to study the compositional differences between grassland still dominated by perennial bunchgrasses (Nassella pulchra) and those dominated by exotic annual grasses. Currently we have identified multiple sites on the reserve that are dominated by each grass type and would like to measure how diversity and abundance of plants and invertebrates differ between these sites. Understanding these compositional differences are important to determining the functionality of the grassland and the potential ease for restoring these invaded communities. Ten paired transects have been selected across the reserve. One of the transects is in a Nassella pulchra dominated grassland, while the other is dominated by exotic annual grasses (namely Bromus diandrus). The transects are 30m in length and will be sampled using a 1m x 0.5m quadrat at ten points along the trasnects. Plant species cover, disturbance, bare-ground and thatch will be recorded for each quadrat. Plant composition will be measured in spring and summer, while invertebrate composition will be measured seasonally. Invertebrate composition will be measured at two quadrats along each transect via three methods: 1) Pitfall traps will be employed to catch ground dwelling invertebrates. Pitfall traps will be made using a plastic cup with a small amount of ethylene glycol in the bottom. A inverted funnel will be placed on top of the cup to excluded larger organisms and to keep insects from being able to crawl out once they have fallen in the cup. The pit fall trap will be sunk into the ground so that the top is flush with the soil surface. 2) Sticky traps will be used to collect aerial invertebrates. Sticky traps will be made using a 2L soda bottle covered with tanglefoot. The stick traps will be placed on sticks on sit 0.5m above the soil surface. 3) de-vac. Each plot will be vacuumed. Pitfall and sticky traps will be left out for 2 weeks and organisms will be removed every other day. Plots will be de-vaced once per season.

Visit #14870 @Sedgwick Reserve

Approved

Under Project # 9692 | Research

The effects of invasion on plant and invertebrate diversity

faculty - University of California, Santa Barbara

Reservation Members(s)

Group of 2 Graduate Student Mar 22 - 23, 2008 (2 days)

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Studio Apartment 2 Mar 22 - 23, 2008