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Filling the weed-shaped hole: Determining an effective planting palette for Strawberry Creek Lauren Hallett, Nathan Bickart, Lawrence Fernandez and Katharine Suding Department of Environmental Science, Policy & Management, UC Berkeley Every year over 500 undergraduates care for Strawberry Creek by pulling the invasive ivy that blankets its banks. Without planting new species, this may create a “weed-shaped” hole that ivy can refill. Our goal was to select and plant species that limit ivy re-invasion. What we did: Species with similar traits to ivy – such as similar growth rates and shade tolerance – should be more competitive. We measured the traits of 40 species to identify plants that can compete with ivy. Shoots

Specific leaf area: Thick leaves last longer and are more drought tolerant

Specific root length & Proportion of fine roots : Thin roots have more surface area but are more fragile

Chlorophyll: Higher leaf chlorophyll content increases photosynthesis rates and growth


Rooting depth: Deep tap roots increase drought avoidance

Conductance: Low conductance means less water is lost during respiration

Root:shoot ratio: Higher root to shoot ratios decrease susceptibility to drought

Height: Greater height is associated with faster growth

Species that clustered near ivy in multivariate trait-space are functionally similar to ivy.

We grew these functionallysimilar species in the Strawberry Creek nursery.

Ivy Ivy

And then planted them along Strawberry Creek.

800 plants

With the help of 250 volunteers

We will keep an eye on these plants over the next year to assess how successfully they compete with ivy. Thanks to: Jesse Fried and Martin Alexander for long hours measuring traits, Tim Pine and the Strawberry Creek Restoration Program for guidance and planting support and Katherine Walsh for logistical help.

2013 Strawberry Creek Filling the Weed Shaped Hole Poster  

A 2012 TGIF Funded Project