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Global Invasive Species Team listserve digest #014 Fri, 22 Jan 1999 18:00:13 -0800 (PST) --CONTENTS-- 1. Pennsylvania needs help controlling hackberry 2. Lygodium (Old world climbing fern) in Florida 3. Mapping weeds for management --------------------------------------- 1. Pennsylvania needs help controlling hackberry From: Betsy Lyman (blyman(at)tnc.org) We have cleared an acre on a limestone ridge in order to restore the warm-season grass prairie. We are planting grass plugs, but have gotten a thick crop of hackberry seedlings (Celtis occidentalis) coming up (these aren't exotics, just very invasive at this site). We've been mowing them, but all that seems to do is cause them to sprout more profusely, so after 2 years, we have a thick, low carpet of dwarfed hackberry seedlings. We'd like to avoid herbiciding because there are so many other plants here we want to spare, but if continued mowing will just cause this mat of hackberry to get thicker, then we will herbicide them. Anyone have any experience dealing with hackberry (including herbiciding experience), we'd appreciate hearing about it. Many thanks, Betsy Betsy Lyman, Stewardship Operations Coordinator The Nature Conservancy - Pennsylvania Field Office Lee Park, 1100 East Hector St., Suite 470, Conshohocken, PA 19428 610-834-1323; 610-834-6533 (fax); blyman(at)tnc.org (email) --------------------------------------- 2. Lygodium (Old world climbing fern) in Florida From: Jil Swearingen (JIL_SWEARINGEN(at)nps.gov) Jil Swearingen forwarded email from Tony Pernas, Resource Manager at Big Cypress National Preserve in Florida... Lygodium micropyllum has been found in the Preserve and adjacent Fakahatchee Strand S.P. as well as the Seminole Indian Reservation. We treated our bunch and our going to assist Fakahatchee and the Seminoles, however this fern is spread by spores and new populations are appearing everywhere. It looks like no habitat type is immune. In Loxahatchee NWR every tree island now has lygodium. Most of these tree islands have a three foot deep rachis mat,(however it is smothering the Brazilian pepper) but everything else also. When it burns, the high heat generated by the burning rachis material kills all of the native plants. Populations of lygodium have been found just east of EVER also. It looks like this one will make melaleuca control look easy. --------------------------------------- 3. Mapping weeds for management From: Donnelle Keech (dkeech(at)tnc.org) I'm interested in improving our methods for preparing maps of weed infestations on our preserves in Maryland. To date, we've used the "draw what you know on a map" method -- a quick and easy way of recording your observations, but often very general, incomplete, or distorted. As we devote more resources to weed management, I find myself longing for more detailed and reliable maps that include information about the presence, location, extent and density of weed infestations. I would like to develop (or pirate!) an efficient, effective and repeatable methodology for completing weed surveys and creating (and updating) weed maps at the preserve scale (that's 10's to 100's of acres in Maryland). In the back of my mind is the thought that a sufficiently clear methodology would facilitate using interns, students, and/or volunteers to help with surveys/mapping. Has anyone ever encountered a methodology (handbook, guidelines...) for surveying and mapping weeds, or analogous features? Any weed mappers out there who can share some good tricks or gems of wisdom? Can anyone suggest any other resources (written or otherwise) that might contribute to this effort? Many thanks for any input. Donnelle Keech Assistant Director of Stewardship The Nature Conservancy -- Maryland/DC Chapter 2 Wisconsin Circle, #300 Chevy Chase, MD 20815 (301) 656-8673 --------------------------------------------------------------- |
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