Buckthorn seems partially shade tolerant here. It's seedling survive under it's own shade, causing a dense impassable massive expanse of tangled buckthorn. It will thrive under bur oaks in savannas and floodplain forests, as well as under oak and hickory on dry glacial moraines, but seems to struggle only under mature forests with completely closed canopies. Thinned, managed forests often allow enough sunlight to reach the ground for them to grow. If grasses can grow there even if only in small patches, it seems that buckthorn will grow there, too, eventually shading out and replacing the grass.
Paul Jost ---- Joseph Zorzin <[EMAIL PROTECTED]> wrote: ============= Re: [ENTS] Re: European buckthorn (Rhamnus cathartica) infestation in the Allegheny National ForestAllowing native trees to grow over and shade buckthorn will help control it. It doesn't seem to do well in heavy shade. Joe ----- Original Message ----- From: Kirk Johnson To: [email protected] Sent: Wednesday, October 01, 2008 4:08 PM Subject: [ENTS] Re: European buckthorn (Rhamnus cathartica) infestation in the Allegheny National Forest No plan in place right now. Probably some combination of herbicides and mechanical treatments. There might be a strategy of simply try to contain the core infested area, and stamp out satellite populations where and when they crop up. From: Elisa Campbell <[EMAIL PROTECTED]> Reply-To: [email protected] Date: Wed, 01 Oct 2008 13:50:05 -0400 To: [email protected] Subject: [ENTS] Re: European buckthorn (Rhamnus cathartica) infestation in the Allegheny National Forest Kirk, is there a plan for control? (I realize eradication is probably impossible at this point) Elisa Kirk Johnson wrote: European buckthorn (Rhamnus cathartica) infestation in the Allegheny National Forest Anyone following Allegheny National Forest (ANF) issues will be hearing a great deal about European buckthorn (Rhamnus cathartica) trees for the foreseeable future. European Buckthorn is a troublesome invasive exotic species, it is not native to the ANF, Pennsylvania, or even North America. European buckthorn was first noted in the Allegheny National Forest (ANF) around 1994 as a small 3-6 acre component of the understory in three to four stands in the Pole Road Run and Davidson Run watersheds in Elk County. Pole Road Run and Davidson Run are tributaries of Bear Creek, which flows south through the proposed Clarion River Wilderness Area and empties into the Clarion River. Buckthorn are small trees reaching 20-25 feet in height and 10 inches in diameter. Most often they grow in a large shrub form, having a few to several stems from the base, with spreading, loosely-branched crowns. Their bark is gray to brown with prominent, often elongate, lighter-colored lenticels. Cutting a branch exposes a yellow sapwood and a pinkish to orange heartwood. The leaves are 1" - 2 1/2" in size, broadly elliptical, finely wavy-toothed, and may be arranged both alternately and oppositely on the same branch. In the fall, leaves remain green and attached after most other species have lost theirs. The fruits are about 5/16" in diameter, similar in structure to a cherry (but containing more than one seed), are very dark colored, and numerous. The seeds can remain viable on the forest floor for several years. The fruits are eagerly eaten by songbirds, and so the seeds are spread widely. It's not necessarily that songbirds prefer buckthorn berries to those of native trees and shrubs, it's often the only option available on severely infested sites. And since the fruit of buckthorn causes a severe laxative effect (hence the species name cathartica), the birds quickly pass the seeds in their droppings. When the trees reach maturity they produce abundant fruit and within a few years there are commonly thousands of seedlings around the base of each mature tree. Also, cut stumps will sprout vigorously. A woodland area severely infested with buckthorn develops into a very poor ecosystem. There is a terrible lack of flora and fauna species diversity, which is critical for a healthy ecosystem. There is a paucity of food and suitable habitat for many wildlife species. In 2001, casual observations made by employees of the ANF noted that buckthorn was reaching significant portions of the Pole Run Road/Davidson Run region. In 2007, the ANF was given additional funds to inventory these infestations and found buckthorn on nearly 3,500 acres -- occupying an area 1,000 times larger than in 1994: 20% (650 acres) -- heavy infestation 35% (1,150 acres) -- moderate 30% (975 acres) -- light 15% (500 acres) -- trace Only 50 out of 3,500 acres surveyed failed to find buckthorn. European buckthorn grows in extremely dense thickets that all but eliminates any chance for native vegetation to reproduce on the forest floor. The Forest Service has found buckthorn growing in forest conditions they never thought possible. Today it can be described literally as a 'plague' on the landscape. Its distribution and rate of spread is truly unprecedented and unequaled. Only the very hardest, most compact rock/clay soils on roads and oil well pads were found to be unsuitable growing sites. Regardless of the width of the road and/or well pad, center of the road and road edges are found to be totally infested. This means that old lease roads, pipelines, skid trails, and well openings are all avenues for the spread and establishment of buckthorn. If any part of these facilities create a break in the forest canopy, buckthorn can invade. Even in these 'waste' areas, buckthorn growth is rapid and unchecked. Only the most saturated wetlands, such as beaver ponds and open seeps have been found to be unsuitable -- while their edges can be totally infested. Although soils that are saturated much of the year are unsuitable, any small 'hummock,' as little as six inches high, found in these areas that drain just a little better were found to support buckthorn. Please keep your eyes peeled for this aggressive invasive plant when out and about in the ANF. If you notice European buckthorn thickets in portions of the ANF not mentioned in this email, please report it to the Forest Service, they will be grateful for your observation. Let them know what drainage you found it growing in, along which Forest Road you observed it growing, etc. Bradford Ranger District: (814) 362-4613 Marienville Ranger District: (814) 927-6628 Young buckthorn trees that are in the three- to five-foot range and smaller can be pulled out of the ground roots & all relatively easily. But cutting them down will only encourage accelerated growth from the cut stump. Additional information on European buckthorn: http://www.uwgb.edu/biodiversity/herbarium/invasive_species/rhacat01.htm http://plants.usda.gov/java/profile?symbol=RHCA3 http://www.nps.gov/plants/ALIEN/fact/rhca1.htm The attached photos of European buckthorn were taken during a September 30, 2008 field trip in the ANF along Forest Road 161A near Pole Road Run, in the heart of the infested area. -- Friends of Allegheny Wilderness 220 Center Street Warren, PA 16365 814-723-0620 [EMAIL PROTECTED] http://www.pawild.org A Citizens' Wilderness Proposal for Pennsylvania's Allegheny National Forest: http://www.pawild.org/exec_summary.html -------------------------------------------------------------------------- -------------------------------------------------------------------------- -------------------------------------------------------------------------- -------------------------------------------------------------------------- -- Elisa K Campbell, Ph.D. Software Support OIT, UMass Amherst (413) 545-1853 fax: (413) 545-3203 ************************************* "I got a simple rule about everybody. If you don't treat me right, shame on you." Louis Armstrong --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org You are subscribed to the Google Groups "ENTSTrees" group. To post to this group, send email to [email protected] To unsubscribe send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/entstrees?hl=en -~----------~----~----~----~------~----~------~--~---
