Project: Consolidated WBP Direct Seeding Trials
Agency/Forest or Park/District: Montana State University
Project coordinator: Dave Roberts
Contact: David W. Roberts, Professor and Head, Department of Ecology, Montana State University, Bozeman, MT 59717-3460, office 406-994-4548, FAX 406-994-3190, email firstname.lastname@example.org
Clay DeMastus, 200 Michael Grove Ave., Bozeman, MT 59718; email@example.com.
Valerie Walker, and John Waverek, Lolo NF; Sidnee Dittman, St. Joe NF; Dan Reinhart, Yellowstone National Park; Bev Yelczyn, Clearwater NF; Nancy Lankford, Mt. Hood National Forest; Richard L. Roberson, Caribou-Targhee NF, Grand Targhee Ski Area; Melissa Jenkins, Flathead National Forest; Jodie Canfield, Mark Novak, Gallatin National Forest; Cda Nursery; Cathy Cripps, Montana State University.
In addition to these direct cooperators, several scientists have been involved in developing this project and will continue to be advisors/consultants for changes or additional treatments. (This includes John Schwandt, Holly Kearns, Diana Tomback, Ward McCaughey, and others.)
Source of funding /amount
Supplemental funding: $15,000 from MSU, FS and Nursery
Dates of restoration efforts
- Investigate what treatments (if any) are most effective at increasing germination of directly sown seeds.
- Investigate what treatments (if any) are most effective at increasing survival of germinants from directly sown seeds.
- Investigate if caging affects germination of directly sown seeds and survival of germinants from directly sown seeds.
- Compare long term survival of directly sown seeds versus long term survival of outplanted nursery grown seedlings.
- Compare germination and survival rate of directly sown seeds in seed caches versus non-cached or individually directly sown seeds.
Acres/ha treated N/A
Six sites throughout the northern Rocky Mountains in the states of Montana and Idaho were chosen to carry out the field experiments described in this chapter. These sites were: Fairy Lake on the Gallatin National Forest near Bozeman, MT, Pioneer Mountain within The Yellowstone Club Ski Area near Big Sky, MT, Toboggan Ridge on the Clearwater National Forest in Idaho, Thompson Peak on the Lolo National Forest near Plains, MT, Ulm Peak on the Idaho-Montana state line west of Thompson Falls, MT, and Gold Pass on Idaho-Montana state line west of St. Regis, MT. These sites were chosen for their whitebark pine habitat and accessibility for ease in set-up and data collection.
In this portion of the experiment, 800 seeds collected from local seed sources were used at each site. The seeds were planted in a complete randomized block design with five replicates of eight treatments with 20 seeds per treatment. Each of the 20 seeds in each treatment was planted 3.25″ apart from one another at a depth of 1.5″ in bare mineral soil. The treatments included; 1) warm stratification (strat), 2) scarification (scar), 3) both the stratification and scarification together (scar + strat), and 4) a control.
These four treatments were installed with and without a 1/2 ″ mesh wire cage in each replicate to make up the eight blocks and treatments. Figure 1 is an example that shows the layout of one site broken down by blocks and treatments. This consisted of eight rows of eight treatments spaced approximately three feet apart for ease in data collection with 20 seeds in each row. Two HOBO® data loggers were also installed at each site to record ground surface temperatures as well as soil temperatures 1.5″ below the surface (depth of sown seed). These were placed in selected caged treatments in various locations throughout the site.
|Single Site||5 Blocks||Single Block|
|(20 Seeds Per Treatment)|
|Scarification + Stratification|
|Scarification + Stratification:Cage|
Figure 1: Schematic layout of a site.
Nursery Seedlings and Seed Caches
Two year old nursery seedlings grown from local seed sources were planted at each site spread throughout the areas encompassing the five blocks. Thirty-four nursery seedlings were planted at the Gold Pass and Thompson Peak sites while 100 were planted at the remaining sites.
At the Fairy Lake, Thompson Peak, Ulm Peak, and Gold Pass sites, caches of three untreated seeds were planted directly next to 32 of the nursery grown seedlings. An untreated seed cache of four was planted next to one of the nursery grown seedlings for a total of 100 seeds in 33 caches. At the Pioneer Mountain and Toboggan Ridge sites, untreated seed caches of three were planted next to 50 of the nursery grown seedlings and warm stratified seed caches of three were planted next to the remaining 50 nursery grown seedlings for a total of 300 seeds in 100 caches.
This study’s initial intent was to analyze the results of direct seeding tests performed in six whitebark pine habitats throughout the northern Rocky Mountains. One of these six sites (Fairy Lake) had very low germination rates and even poorer survival rates. This particular site is unique because it has both limber pine (Pinus flexilus) and whitebark pine growing within the same general area. In Montana, this is a rarity as there are only few sites that posses this same characteristic (Pfister et al. 1977). Limber pine is phenotypically similar to whitebark pine. The best visual discerning feature that separates the two species is the difference in their unique cones. Whitebark and limber pine use mast seeding to improve their fitness. Some years there are bountiful amounts of cones and other years it is difficult to find even one cone on a particular tree. The year the Fairy Lake site was installed (2009) was not a mast year. Because of this, the difference between the two species at this site was very difficult to discern. The site was thought to be installed in whitebark pine habitat because there where known whitebark pine plus trees that where used in past cone and scion collections by local Forest Service crews close by and were marked with identification tags. However, throughout the course of the study, it became apparent in mast years (2010 and 2011) that the site had been installed in a zone transitioning from limber habitat to whitebark habitat. It is thought that this along with the fact that it was a dry, rocky and more harsh site could have been the reason such poor germination and survival occurred here. Because of this, the decision was made to not include the data from the Fairy Lake site in the final analysis.
Germination results are presented below in tables 1 and 2.
Table 1: Excerpt of the summary of the final model of germination.
Estimate Std. Error t value Pr(>|t|)
(Intercept) -9.592e-01 4.308e-01 -2.226 0.027650
sitepioneer -4.254e-01 6.200e-01 -0.686 0.493810
sitethompson 3.483e-01 6.050e-01 0.576 0.565746
sitetoboggan 1.311e+00 5.870e-01 2.233 0.027199
siteulm 2.014e-01 6.043e-01 0.333 0.739397
seedscar -6.190e-01 3.335e-01 -1.856 0.065591
seedscar+strat 4.171e-01 3.203e-01 1.302 0.195087
seedstrat 1.299e+00 3.339e-01 3.891 0.000156
sitepioneer:seedscar 1.526e+00 4.832e-01 3.158 0.001960
sitethompson:seedscar -2.116e-01 4.922e-01 -0.430 0.667936
sitetoboggan:seedscar 4.911e-01 4.612e-01 1.065 0.288851
siteulm:seedscar -7.624e-01 5.488e-01 -1.389 0.167047
sitepioneer:seedscar+strat -1.038e-01 4.768e-01 -0.218 0.827923
sitethompson:seedscar+strat 5.249e-01 4.615e-01 1.137 0.257411
sitetoboggan:seedscar+strat -7.191e-01 4.534e-01 -1.586 0.115078
siteulm:seedscar+strat 1.809e-01 4.625e-01 0.391 0.696288
sitepioneer:seedstrat -2.715e-01 4.831e-01 -0.562 0.575062
sitethompson:seedstrat -5.780e-01 4.700e-01 -1.230 0.220905
sitetoboggan:seedstrat -1.470e+00 4.618e-01 -3.183 0.001807
siteulm:seedstrat -3.002e-01 4.724e-01 -0.636 0.526156
Null deviance: 928.68 on 199 degrees of freedom
Residual deviance: 339.13 on 135 degrees of freedom
Table 2: Estimated germination percent and 80% confidence intervals at each site by treatment.
|Site||Treatment||Estimated Germination (%)||80% CI (%)|
|Gold Pass||Control||27.8||17.4 to 41.0|
|Gold Pass||Scar||17.1||10.0 to 27.7|
|Gold Pass||Scar + Strat||36.8||24.4 to 51.2|
|Gold Pass||Strat||58.4||43.5 to 71.9|
|Pioneer Mountain||Control||20.0||11.9 to 31.7|
|Pioneer Mountain||Scar||38.3||25.5 to 52.9|
|Pioneer Mountain||Scar + Strat||22.5||13.7 to 34.6|
|Pioneer Mountain||Strat||41.5||27.9 to 55.9|
|Thompson Peak||Control||35.2||23.2 to 49.4|
|Thompson Peak||Scar||19.1||11.3 to 30.6|
|Thompson Peak||Scar + Strat||58.2||43.8 to 71.4|
|Thompson Peak||Strat||52.8||38.3 to 66.7|
|Toboggan Ridge||Control||58.7||45.0 to 71.2|
|Toboggan Ridge||Scar||55.6||41.9 to 68.5|
|Toboggan Ridge||Scar + Strat||51.2||37.7 to 64.6|
|Toboggan Ridge||Strat||54.5||40.9 to 67.5|
|Ulm Peak||Control||31.9||20.7 to 45.7|
|Ulm Peak||Scar||10.5||5.8 to 18.5|
|Ulm Peak||Scar + Strat||46.0||32.4 to 60.2|
|Ulm Peak||Strat||56.0||41.7 to 69.3|
As can be seen from table 2, stratification generally results in the best germination results, except at Thompson Peak where scarification+stratification performed best, and at Toboggan Ridge where treatments did not differ.
Survival results are presented in Tables 3 and 4.
Table 3: Excerpt of the summary of the final model of survival.
Estimate Std. Error t value Pr(>|t|)
(Intercept) -0.43262 0.57004 -0.759 0.449178
sitepioneer 1.32350 0.82193 1.610 0.109614
sitethompson 1.68553 0.71830 2.347 0.020360
sitetoboggan 2.37399 0.74875 3.171 0.001872
siteulm -1.48856 0.74456 -1.999 0.047531
seedscar 0.06709 0.45638 0.147 0.883346
seedscar+strat -0.18488 0.39546 -0.467 0.640879
seedstrat -0.57778 0.36279 -1.593 0.113519
sitepioneer:seedscar -0.04934 0.63264 -0.078 0.937942
sitethompson:seedscar -0.72066 0.69032 -1.044 0.298319
sitetoboggan:seedscar -0.61050 0.68719 -0.888 0.375858
siteulm:seedscar -0.30251 0.90995 -0.332 0.740053
sitepioneer:seedscar+strat -1.02198 0.60630 -1.686 0.094114
sitethompson:seedscar+strat -0.19623 0.55727 -0.352 0.725271
sitetoboggan:seedscar+strat 0.20137 0.68780 0.293 0.770133
siteulm:seedscar+strat 1.46592 0.61491 2.384 0.018479
sitepioneer:seedstrat 0.07272 0.55811 0.130 0.896522
sitethompson:seedstrat 0.69073 0.54866 1.259 0.210161
sitetoboggan:seedstrat 0.68328 0.67702 1.009 0.314612
siteulm:seedstrat 2.02245 0.58307 3.469 0.000697
Table 4: Estimated survival percent and 80% confidence intervals at each site by treatment.
|Site||Treatment||Survival (%)||80% CI (%)|
|Gold Pass||Control||39.4||26.0 to 54.5|
|Gold Pass||Scar||41||27.5 to 56.0|
|Gold Pass||Scar + Strat||35||23.1 to 49.2|
|Gold Pass||Strat||26.7||17.5 to 38.5|
|Pioneer Mountain||Control||70.9||56.4 to 82.1|
|Pioneer Mountain||Scar||71.3||57.8 to 81.8|
|Pioneer Mountain||Scar + Strat||42.2||32.5 to 52.5|
|Pioneer Mountain||Strat||59.5||45.5 to 72.2|
|Thompson Peak||Control||77.8||68.7 to 84.8|
|Thompson Peak||Scar||64.6||51.2 to 76.0|
|Thompson Peak||Scar + Strat||70.5||61.0 to 78.5|
|Thompson Peak||Strat||79.7||71.5 to 85.9|
|Toboggan Ridge||Control||87.5||80.6 to 92.1|
|Toboggan Ridge||Scar||80.2||71.1 to 86.9|
|Toboggan Ridge||Scar + Strat||87.6||80.3 to 92.5|
|Toboggan Ridge||Strat||88.6||81.5 to 93.2|
|Ulm Peak||Control||12.8||8.1 to 19.7|
|Ulm Peak||Scar||10.4||4.9 to 20.8|
|Ulm Peak||Scar + Strat||34.5||26.4 to 43.7|
|Ulm Peak||Strat||38.3||30.0 to 47.4|
Survival varied significantly by site but stratification was helpful at all but one site.
Combined Germination and Survival
Previous results detailed germination and survival of germinants separately, but clearly it is the product of both that is significant to future whitebark pine. Combined germination and survival statistics are presented in Tables 5 and 6.
Table 5: Excerpt of the summary of the final model of combined germination and survival.
Estimate Std. Error t value Pr(>|t|)
(Intercept) -2.14591 0.53677 -3.998 0.000103
sitepioneer 0.37338 0.71148 0.525 0.600554
sitethompson 1.43538 0.67178 2.137 0.034351
sitetoboggan 2.28682 0.64660 3.537 0.000549
siteulm -0.96513 0.72999 -1.322 0.188271
seedscar -0.50209 0.35262 -1.424 0.156689
seedscar+strat 0.19741 0.32645 0.605 0.546337
seedstrat 0.44583 0.31686 1.407 0.161621
sitepioneer:seedscar 1.25092 0.49292 2.538 0.012243
sitethompson:seedscar -0.57429 0.54868 -1.047 0.297048
sitetoboggan:seedscar 0.20929 0.46074 0.454 0.650344
siteulm:seedscar -0.73468 0.88739 -0.828 0.409123
sitepioneer:seedscar+strat -0.53308 0.50279 -1.060 0.290853
sitethompson:seedscar+strat 0.19249 0.46788 0.411 0.681407
sitetoboggan:seedscar+strat -0.51369 0.44140 -1.164 0.246482
siteulm:seedscar+strat 1.09962 0.57993 1.896 0.059991 .
sitepioneer:seedstrat 0.13055 0.46984 0.278 0.781528
sitethompson:seedstrat 0.07096 0.45988 0.154 0.877592
sitetoboggan:seedstrat -0.60093 0.43202 -1.391 0.166428
siteulm:seedstrat 1.30631 0.56441 2.314 0.022086
Table 6: Estimated combined germination and survival percent and 80% confidence intervals at each site by treatment
|Combined Germination and Survival Estimates|
|Site||Treatment||Estimated Germ. + Surv. (%)||80% CI (%)|
|Gold Pass||Control||10.5||5.9 to 18.0|
|Gold Pass||Scar||6.6||3.6 to 11.9|
|Gold Pass||Scar + Strat||12.5||7.1 to 21.0|
|Gold Pass||Strat||15.5||9.0 to 25.3|
|Pioneer Mountain||Control||14.5||8.6 to 23.5|
|Pioneer Mountain||Scar||26.4||16.9 to 38.8|
|Pioneer Mountain||Scar + Strat||10.8||6.2 to 18.3|
|Pioneer Mountain||Strat||23.2||14.6 to 34.9|
|Thompson Peak||Control||33.0||22.5 to 45.3|
|Thompson Peak||Scar||14.3||8.5 to 23.2|
|Thompson Peak||Scar + Strat||42.1||32.8 to 51.9|
|Thompson Peak||Strat||45.2||32.9 to 58.0|
|Toboggan Ridge||Control||53.5||41.6 to 65.0|
|Toboggan Ridge||Scar||46.2||34.7 to 58.1|
|Toboggan Ridge||Scar + Strat||45.6||34.2 to 57.6|
|Toboggan Ridge||Strat||49.7||37.9 to 61.4|
|Ulm Peak||Control||4.3||2.7 to 6.5|
|Ulm Peak||Scar||1.3||0.5 to 3.2|
|Ulm Peak||Scar + Strat||14.0||11.0 to 17.8|
|Ulm Peak||Strat||20.4||13.8 to 29.1|
Table 7: Caged versus non-caged estimated germination rates comparison by treatment and site.
|Site||Treatment||Non-Caged Germ. (%)||Caged Germ. (%)|
|Gold Pass||Scar + Strat||36.8||38.9|
|Pioneer Mountain||Scar + Strat||22.5||39.7|
|Thompson Peak||Scar + Strat||58.2||40.0|
|Toboggan Ridge||Scar + Strat||51.2||42.5|
|Ulm Peak||Scar + Strat||46.0||50.1|
|Table 8. Cage and Non-Caged Survival Estimates|
|Site||Treatment||Non-Caged Surv. (%)||Caged Surv.(%)|
|Gold Pass||Scar + Strat||35.0||57.5|
|Pioneer Mountain||Scar + Strat||42.2||62.6|
|Thompson Peak||Scar + Strat||70.5||67.1|
|Toboggan Ridge||Scar + Strat||87.6||94.9|
|Ulm Peak||Scar + Strat||34.5||55.4|
Future monitoring of test sites will depend on the availability of funding; no plans exist at present to undertake such monitoring.
Whitebark pine seed treatments of warm stratification and warm stratification and scarification together were found to have significantly increased germination under natural field settings compared to the scarification treatment at two sites. Warm stratified seed was found to have significantly higher germination rates than scarified seed and untreated control seed at one of the other three sites. As a whole, warm stratified seed had the highest germination rates as estimates did not drop lower than 41% at any of the sites. The other three treatments had germination rates below this mark at multiple sites.
Survival rates of whitebark pine germinants from directly sown seed were similar between treatments with a few exceptions. The control and scarification treatments were found to have significantly higher survival rates than seed undergoing both scarification and warm stratification at one of the five sites. Warm stratified seed and seed undergoing both stratification and scarification were found to have significantly higher survival rates than the untreated control and scarified seed at one of the remaining four sites.
Warm stratified seed and seed undergoing both warm stratification and scarification were found to have significantly higher combined germination and survival rates than scarified seed at one of the five sites and significantly higher combined germination and survival rates than untreated control seed and scarified seed at the one of the remaining four sites. Warm stratified seed had the highest estimated combined germination and survival rates at three of the five sites. This same treatment had the second highest estimated combined germination and survival rates at the remaining two sites and was surpassed by the treatment with the highest estimated rates by only three percent at both of these two sites.
Caging directly sown seed was shown to have a positive effect on germination and survival that is dependent on both site and block. Caging was also shown to have a positive effect on survival that is dependent on seed treatment. It is thought that this caging effect on survival could be due to an unexpected cooling effect brought about by the shade provided by the cage. The shade provided by the cage is minimal but possibly significant enough to decrease temperatures, which results in a decrease in evapotranspiration, ultimately resulting in an increase in survival.
Outplanted nursery grown seedlings had significantly higher survival rates than the combined germination and survival rates of seeds sown in caches after two and three years of observation. Ideally the data concerning this aspect of the experiment will continue to be recorded on a yearly basis in the future to monitor long term survival.
Cache seed germination rates were lower than seeds planted alone (non-cached) at all sites except one, Thompson Peak. Cache seed survival rates and non-cache seed survival rates were very similar at all five sites as no significant difference was found.
Soil surface temperatures had higher volatility than subsurface temperatures and winter temperatures stayed very close to freezing once there was snow cover. The number of extreme temperature events at a site is estimated to increase survival of germinants from directly sown seeds. However, this is probably not the cause of increased survival and results such as this are likely an indicator that one or many other important variables affecting survival are not accounted for in this study.