Tree Selection Models

[John S. Weedon]

Species recommendations for farmers planting trees in pastures usually assumes the weather in 25 years will be the same as today. Given climate change, that assumption is likely incorrect.

Is anyone aware of species distribution models (SDM) that farmers might be able to use easily to help decide which trees will survive and thrive for a specific site under various climate scenarios?  Or, if SDM aren't the appropriate tool, what could farmers and agroforesters use to glimpse the future?

[Edmund Brown]

Look south? And more arid? That's what I do when I ruminate on what my CNY farm might look like like 40-50 years from now. There are so many variables that putting any stock in a detailed model seems every bit as fraught as just looking several hundred miles south for a guide to what will thrive. Trying to find a comparison site with similar soils to whatever you're managing would probably be a good idea... Just my two cents.

[Richard Moyer]

John,  We live and farm in the southern Appalachians, and appreciate your questions.  New to this forum, will just throw out a few ways to answer your question, then glad to expand on any of these.  I agree with Edmund that awareness of soil types you are planting in, some trees languish in certain soils, others more widely adapted.

---The southern Appalachians have 300 woody species, more than all of Europe.  We have extremes here of heat, cold, rain, snow, severe freezes, etc.  But if 300 woody species thrive here (some highly specialized), there is a lot to choose from that may work for you.

---Google any tree you are interested in, plus 'range map'.  I prefer the USDA-NRCS plants database, though at the county level it's incomplete:  http://plants.usda.gov/java/  You can enter common or scientific names of trees you want to learn about.

View those maps with range edges that ignore state boundaries and are scalable down to county level, to see which tree species already exist in far WNY, Hudson Valley, or scattered throughout the state, to see what might work so is worth chancing, at least as a % of your overall planting mix.  In my lifetime I've seen tree species I didn't grow up with that are thriving here now, so these maps are often looking back and not forward.  But they do tell us what works where we are now, and also where else these trees thrive. Others on this list please weigh in with preferred range map sites.

---Also, keep in mind that though eastern US forests have the genetic diversity to withstand eons of weather extremes, they don't have immunity to certain insects and disease complexes suddenly introduced from other areas.  Through our increasingly globalized commerce.  So avoiding "all eggs in one basket", plant a diversity of tree species in case some are taken out early by pestilence.

---Maple Examples:   Red maple is happy from S. Florida up into Canada, all up and down the eastern US.  Very well adapted to a range of weather  and soil conditions.  So even if your farm turns into Florida weather in 25 yrs, Red maple will likely still be happy.

---Sugar Maple:  Am currently visiting my family in eastern GA, the southern edge of sugar maple range.  Found a number of these in river flood plains we were exploring yesterday.  This an area that has weeks per summer over 100F, and nights in the 80s, with very high humidity.  Other tree species may gain an advantage with weather changes, but sugar maples can handle weather extremes.  Over decades, cattle in the woods on the farm we bought have selectively grazed other saplings out and left sugar maple, so we tap a healthy maple woods where cattle still graze several times a year.  Red maple blooms early and long, so great food source for spring pollinators who survived the winter.

---Box elder:  http://plants.usda.gov/core/profile?symbol=ACNE2  Again vacationing in GA, we see this one at the southern edge of its range, it does very well in the S. Appalachians on open pasture, creating a spreading,open tree which works well for shade, and also works well in syrup blends.  Also a preferred wood for oyster and other mushroom culture. Note box elder thrives in drainages in the Canadian prairie, testament to its ability to handle weather extremes.  Though this range map shows it only in scattered NY counties, being scattered through the great basin out west, that's a tough tree. 

Other trees:

---Black Locust:  http://plants.usda.gov/core/profile?symbol=ROPS  Though the native range was once much smaller, it has been spread widely throughout N. American and around the world.  Works well in the dry meditteranean climate, as a browse species for goats, during the dry times of the year.  Our cattle seek out leaves they can reach.  This is one that's happy in new places.  And colonizes easily, perhaps, too easily for some pasture situations.   Nitrogen fixer; new sprouts thorny.  Good bee tree for nectar.

---Black walnut:  http://plants.usda.gov/core/profile?symbol=JUNI  Leafs out late and drops leaves early, leaves rot easily.  Certain plants don't do well under walnuts, but bluegrass and orchardgrass do very well there on my farm.  Timber, nuts and syrup are all potential value added products.

---Two other trees which work well in the open on our farm, and have value as nectar for bees, timber, and mushroom logs:  Tulip poplar and black cherry.

Medium sized mast trees:  Pawpaw, persimmon, honey locust (thornless cultivars )  Each of these can reach 40 ft or more under good conditions, and provide valuable food for animals and even people.  Though not widespread throughout NY, they have potential.

On any of the above, there is value in planting seedlings derived from trees in similar conditions, or per the topic here, seedlings from areas that approximate what weather may become.  Good nurseries will know where their seeds were collected, or can find out.

Seedlings from all the trees above can grow in the open, that is they don't need shade to get started.  We have a lot of trees to choose from!