Winter is time for forest health

Winter may seem like a time when there’s not a lot going on in the forest, so you may be inclined to kick back by the fireside and watch the rain fall outside. However, wintertime is actually one of the best times to take actions for improving your forest’s health.

The cold wet weather reduces wildfire risk, which means the use of machinery, such as chain saws and brush trimmers, is less likely to ignite a fire. Work done during the winter also avoids disturbing bird nests, which are typically active from April through August. So now’s the time to cut down invasive plant infestations, reduce brushy wildfire ladder fuels within 30 feet of your home, and prune up lower tree branches on younger Douglas fir trees. Weeds such as blackberry or Scotch broom growing along edges and gaps of the forest and ivy and clematis growing up trees are examples of ladder fuels since they provide a way for fire to move from the forest floor up into the canopy where it will cause much greater damage. Cutting alone won’t remove these weeds permanently, so be prepared to also dig up the roots or plan for later follow-up treatments. Conveniently enough, the moist soil makes removal of weed roots much easier too!

worker with chainsaw in thick stand of very small alder trees

A forest worker thins small, overly dense red alder trees. Thinning will allow the remaining trees to grow more vigorously and be healthier.

Winter is also a great time to find English ivy in your forest since the evergreen leaves of English ivy stand out more once our broadleaf trees have dropped their leaves and our diverse native wildflowers have also gone dormant. When you find small patches, go ahead and pull it from the ground and cut it off of the trees up to about 6 feet above ground. No need to pull vines down out of the tree; the cut vines will die on the tree. While you’re scouting for ivy, also keep an eye out for and pull seedlings of English holly and laurel.

One thing that’s at the height of activity in the forest during winter is the flow of streams. Culverts allow streams to pass under forest roads and driveways, however during winter storms, they are especially vulnerable to damage or failure as they can become clogged with soil, wood, and other debris. Poor culvert performance also leads to increased sediment entering our streams which can harm fish and other aquatic life. Culverts need annual maintenance, and we encourage you to inspect them a few times during winter to make sure they’re draining properly. If you stay on top of it, you’ll often be able to clear debris with a shovel or other hand tools.

Finally, winter and spring are opportune times to start planning for future forest health projects. If, for example, you are surprised to find an overwhelming amount of ivy that has been growing unnoticed, or you want to thin an overcrowded young forest stand and aren’t quite sure how to go about it, contact us and we may be able to help you craft a plan.

logs on a forest floor among ferns

Cutting fallen logs into smaller lengths allows them to lay flush with the ground which is important for reducing wildfire fuels and for helping the logs decompose faster.

Former holly orchard will nourish a new forest

Guest post by Laura O. Foster

In a blue-sky week in early November, a Rayco track mulcher began chewing up mature holly trees in a 13-acre orchard on McNamee Road. With the last commercial harvest from the orchard almost 10 years prior, the property owner, Dr. Ivan Law, had decided to repurpose his land. “I had been thinking of clearing it out for a while,” Law said.

He found a partner for the job in the West Multnomah Soil and Water Conservation District (WMSWCD). Michael Ahr, Forest Conservationist at WMSWCD, explains how the process worked for Dr. Law, and how other landowners can work with the District on projects to improve their land’s value and wildlife habitat, and to improve regional water quality.

14 months in the planning

When Law contacted the District in September 2018, Ahr and his team jumped into action. Holly is an invasive species, and not the highest economic use for Oregon forestlands. The first step was to survey the property and create a management/conservation plan, based on the owner’s priorities. In this case, the plan recommended holly removal (along with 4 acres of blackberry) and replanting with either timber or pollinator species, in accordance with Law’s goals for his land.

Once a conservation plan is in place for a property, federal funds can be accessed. In this case, Law applied for a Natural Resources Conservation Service (NRCS) grant. Ahr, who is certified to write NRCS conservation plans, helped with technical details.

Requests for proposals went out in late winter 2019. Ahr didn’t specify in the RFP how the holly should be removed, but did require it either be hauled offsite or chipped. After reviewing six bids, Ahr awarded the contract to Hillsboro-based V & K Construction, owned by father-son team Vernon and Kerry Nussbaumer. They also did recent grading work at the Skyline Grange.

Instead of cutting and hauling, Kerry Nussbaumer chose a track mulcher, which chews up a tree from the top down and spits out material fine enough to replant in. The finer material leaves nutrients in place and decomposes faster, resulting in less debris that could fuel a forest fire. The mulcher also eliminates the carbon impact of scores of truckloads of debris being hauled offsite.

As the mulcher began chewing through the orchard, one happy surprise was revealed: many thriving alder, Douglas fir and cedar that had volunteered and grown hidden for decades. Nussbaumer deftly maneuvered the mulcher around the trees, saving them, and giving Law an unexpected head start on reforesting his land. “These guys are very professional,” Law said, as the tree-clearing work proceeded into mid November.

“Weed pressure” as Ahr calls it, is always a problem after invasive species are removed and before new plantings mature. Carefully targeted use of herbicides is often the most effective treatment for certain invasive species. In some cases one spraying is not enough. For Law’s site, emerging weeds (and any holly that resprouts from stumps and the seed bank) will be sprayed only as needed over the next five years. Replanting in February 2021 will likely be in a Douglas fir mix, because fir grows fast and gets above the weeds, shading them out.

WMSWCD has funds to help landowners complete projects

Dr. Law’s land is some of the 14,000 acres held as nonindustrial private forests, or what Ahr calls family forests, in western Multnomah County. Of these, only 10 percent, or 1,400 acres, have a conservation or management plan in place. (Another 600 acres are currently in process of formulating a plan.) Along with giving landowners fascinating insights and details about their land from an experienced forester, the plans are the beginning point for accessing funds for forest, field or watershed improvement projects.

Property owners have worked with WMSWCD to remove blackberry, holly, and ivy, and to plant pollinator and timber species. Other projects have been to repurpose Christmas tree farms. Projects are often multi-year, with stages for removal, spraying if required, replanting, and respraying as needed. The District provides expertise, buys plant material at costs below what a landowner would pay, hires contractors, and is a conduit for federal and state funds. Landowners contribute via their own labor on parts of the project, and sometimes with a cash outlay that represents a small part of the total financial costs. Most forest improvement projects, Ahr says, are in the $5,000 to $10,000 range.

Much of the acreage in Skyline family forests was last commercially logged in the 1980s or 1990s, before timber companies sold the land to be developed. “Our wheelhouse is to work with landowners whose trees were planted in the 1990s,” Ahr says. “You might have 200 to 300 quality trees per acre, but they’re not thriving because of competition from shrubs and less desirable trees like bitter cherry or maple.” Many of those acres need thinning. The District can help with costs and logistics to make a forest more productive, if harvest is the goal.

Most WMSWCD projects are much smaller than Dr. Law’s orchard replanting.  For example, Ahr says that for many properties, the transition zone between forest and residential areas is filled with non-native Himalayan blackberry. Removing it and replanting with pollinator species such as snowberry and currant is a small, easy-to-implement improvement that enhances property aesthetics and value, and creates good habitat for wildlife.

Start with a plan!

If you have a project for your land, and want to access WMSWCD’s expertise and funding, contact them right away. Developing a plan and applying for available funds takes time. Ahr says, “Now is a great time to contact us.”

Laura O. Foster is the author of eight Oregon guidebooks and has worked with WMSWCD on conservation projects on her own property.  

Understory Seeding Project Update

Two of our conservation staff – Michael Ahr, Forest Conservationist, and Laura Taylor, Conservationist and Education Coordinator – are in the second year of a forest understory seeding pilot project that kicked off in September of 2017. We are working on trial sites with eight landowners in the Tualatin Watershed to look at the effectiveness of establishing native understory plants from seed. We hope to learn which species perform best, which species are suited to certain growing conditions, and if so, what are those conditions.

Biodiversity is important for wildlife habitat and ecosystem health, and native plants are under constant pressure from invasive plant species like ivy (Hedera species), garlic mustard (Alliaria petiolata), and invasive geraniums. And in cases where we have helped remove invasive plants from forest understory, we want to be sure to replace them with native plants. Planting from seed offers a number of benefits over planting seedlings. It would be less labor intensive, seeds more quickly replace the herbaceous layer of the forest compared to seedlings or shrub plantings that would grow into a much different forest layer, and finally with seeding, we have a better chance of not introducing new pests that might come along with soil from a nursery.

Seedlings on forest floor

So far, establishing native understory plants from seed appears to be working, especially on test plots where the ground was cleared of dead leaves and sticks. Of course, raking the forest is not a realistic activity nor recommended on a large scale as it disturbs soil structure and wildlife — salamanders, newts, insects, and other macro invertebrates in particular. However raking small patches would be helpful for germinating seeds. Landowners looking to establish native seed plots can cast seed into areas where bare soil is already exposed, or consider raking 3-foot by 3-foot areas here and there to create pockets of native understory that would hopefully spread.

The pilot will continue through September 2020 and beyond. We hope to learn which seeds are the most successful, so we can incorporate use of those seeds into future forest restoration projects, and eventually also find a source for seeds. Many of the seeds used in the pilot are very difficult to find commercially, so another long term goal will be to encourage nurseries to cultivate more of the desired native species for seed collection.

This project is funded by a Conservation Innovation Grant of the USDA Natural Resources Conservation Service. Learn more about the project in this presentation.

Hoo, who do you want in your tree?

 Barn owl
 Barred owl
 Great horned owl
 Northern pygmy owl,
courtesy of Greg Gilson
 Western screech owl

Helpful tips for supporting owls via artifical nesting habitat:

1. Owls eat rodents for the most part.  Every habitat seems to be rodent habitat to some extent so there’s not much you can do to increase the food resource.  If you have some edge habitat with trees growing next to open grass, that can be a good place to see owls hunt.  They’ll rest in the forest, and then move to the edges to hunt the open ground at dusk.   They will eat small birds sometimes, but typically birds are inactive at night when the owls are hunting.

2. Common owls in our region: great horned, barred, barn, and western screech.  Barred, barn, and screech owls nest in cavities often.  Owl boxes can be good for these species, but if the box has a big hole, that may be good for barred owls but not screech owls.  A small hole could be good for the screech but not the barred, so some variety  in hole size may help your chances of getting owls.  The owls would likely have been using these boxes over the last couple of months and could still be using them to raise young right now.  Great horned owls will use next boxes some, but they also frequently nest in abandoned hawk and squirrel nests – so they don’t always focus on the cavities.  Barn owls really like the nest boxes, but if there are numerous barns in the area, they truly do use the rafters as habitat too and may not be looking for natural or artificial cavities in the forest.  Even a small hole in a barn can allow the barn owl to enter and exit the barn.

3. If you have lots of large dead trees or snags, the owls may find cavities in those and use them instead of artificial boxes.

4. You can monitor the boxes to make sure raccoons are not using them instead of the owls.

5. Try changing the orientation on boxes.  Example, if they face north now, try facing them south to see if that changes anything.  Not sure about owls, but bats are more likely to use SE facing boxes because they warm up more quickly in the morning.  Facing boxes towards clearings and away from prevailing winds can help.

6. Plant some conifers if you don’t have many.  Douglas-fir and western redcedar can be good trees for owls because they can find cover and hide out a bit in the winter when the deciduous trees have no leaves.

7. Attracting songbirds or owls to nest boxes can be difficult and sometimes just requires a bit of luck.  They are territorial, so if a neighbor mentions having owls, you may not have any on your property just because they are giving another breeding pair some space to avoid altercations.

For more information on Oregon owls, please visit Oregon Department of Fish & Wildlife: