Exclosures Island Wide

Amy Catalano, Fence Technician, June 24, 2013.

Exclosures in approximate chronological order: Total number: 73 Exclosures

Goat Harbor(Fire in 1999, built in 2000 - 2002) - 10 ironwood, 3 Island Scrub Oak, plastic with metal component.

Study completed. Paper published.

Fences should remain up. They are protecting ironwood groves and other endemic vegetation.

Wild Boar Gully(1999) - 1 metal fence; approximately 100 acres

Construction paid for partially by US Fish and Wildlife for protection of federally endangered Cercocarpus traskiae. Since built, discovered federally endangered Sibara filifoliaand one Dissanthelium californicainside fence as well, only known populations on Catalina. Fence is at high priority to maintain, takes much less input than plastic fences. Occasional breaches due to stream flooding, but easy to fix. Maintained a few days a year, along with other work in area.

Last checked Aug 25, 2017 by L.Roll and R.Rudy

Euphorbia Haven(2000) - 1 exclosure, plastic

Fence was protecting half of an outplanting of the rare CNPS listed plant with only one natural population on the island, and farthest north extent of this plant in the world. The outplanting was designed to test damage by herbivores on this species, herbivory was found to be occurring on plants planted outside fence.

Fence is no longer intact.

REMOVE

Outplanting trial exclosure inside Middle Ranch gates(2001) 1 plastic

Protects outplanted plants. Fence should remain up to protect plants. Small and easy to maintain, needs a few minutes of fixing a year, close to office.

Last checked March 4, 2013.

REMAIN UP

Grass Production Field(2001) 1 plastic with metal. Removed in 2009.

Harding Grass Trial(2002) - 1 plastic fence with metal bottom Removed in 2012.

Airport Burn(2003) - 3 exclosures, plastic

These fences were part of an experimental design, but weren’t able to be maintained frequently enough. Very steep area. The data was not as helpful as it could have been due to breaches, but still showed significant effects of browse on plant height.

Fences currently broken. Not maintained since 2006.

REMOVE

Oak Limitation Trials(2004) - 15 exclosures, plastic fences Some removed in 2013.

Built as part of study for establishment of oaks. Last data taken 2009. Fences not really maintained, but were checked in 2009 and fixed. One burned in Echo Lake fire in 2010.

REMOVE

Empire Burn(Fire in 2006, built in 2007) - 19 exclosures, plastic

Built as part of experimental design of monitoring project, as well as to serve as sources of mature, seed producing plants quicker than browsed surroundings. Most fences still functional, but hard to find time to fix them. Have taken five years of data. Recommend leaving exclosures for several more years. Need to find time/expertise to write up study.

REMAIN UP.

Junction Burn(Fire in 2006, built in 2007) 1 exclosure, plastic. Removed in 2009

Island Fire(Fire in 2007, built in 2008) 5 large exclosures, 6 small, plastic

Most large exclosures reworked to make functional, had to reduce area protected significantly, from approximately 400 acres to 60. Plastic fences have to be less than 30 acres and the perimeter able to be checked entirely during a single outing to ensure effectiveness. Also very beneficial if entire exclosure can be observed at one time. Fences that are functional should remain in place until at least 2015, though longer may be warranted as some plant species will only begin setting seed after ten years or more of growth. Even tall plants are subject to girdling by rubbing of antlers (this killed the majority of plants in the portion of the Goat Harbor exclosure that was removed as a demonstration). If the seed banks of these rare plants do not get restocked, species shifts can occur on a large scale. See table at end of document.

KBRT/Women’s club grove(2010) 1 acre exclosure, plastic

Built from reused fence by the KBRT radio station to protect Cercocarpus traskiaeoutplanting and plants from the Women’s Club Grove. The exclosure and outplanting satisfy a portion of a grant from NRCS to plant Cercocarpus traskiae. This grant gave CHIRP significant funding for years. Project will need to be completed by end of 2011 and certified by NRCS.

Checked weekly.

REMAIN UP

Not strictly exclosures, but fences needing repairs.

FAR fences- Occasional volunteer work done, many repairs needed.

Bison Vegetation Plots-12 small plots fenced as part of experimental design for research on the bison by Rick Sweitzer, Juanita Constible, and Dirk Van Vuren at UNorth Dakota and UCDavis. They recommended strongly that we should continue collecting this data, but haven’t had staff time to do so. Would be hard to refind sub-plots, last monitored in 2006.

REMOVE

Mapped through a combination of GPS points taken at fence corners and aerial photo interpretation.