Treesearch

Investigating how genetic variation is distributed across the landscape is fundamental to inform forest conservation and restoration. Detecting spatial genetic discontinuities has value for defining management units, germplasm collection, and target sites for reforestation; however, inappropriate sampling schemes can misidentify patterns of genetic structure. Appropriate sampling is more critical in fragmented landscapes where patterns of genetic diversity and structure might not yet reflect the current landscape structure. Landscape genetic simulations are useful for assessing the...

Whitebark pine (Pinus albicaulis) and foxtail pine (P. balfouriana) are conifers native to western North America. Due to several threats, including a non-native pathogen (Cronartium ribicola) and a changing climate, whitebark pine and foxtail pine are classified on the IUCN Red List as ‘endangered’ and ‘near threatened,’ respectively. Whitebark pine has been proposed for listing under the Endangered Species Act (ESA) in the United States and is now listed as endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Ex situ genetic conservation activities are...

We recently established a study to evaluate the effects of several riparian restoration treatments on degraded streambanks located on the Finger Lakes National Forest (FLNF) in western New York. A legacy of cattle grazing has led to soil compaction, invasion by non-native invasive plant species (NNIP), as well as heavy nitrogen loading and increased bacterial levels in riparian corridors on the FLNF. These characteristics slow the conversion of non-native grassland to closed-canopy forest, a FLNF management goal for these sites. We are testing two planting treatments: tree vs. mixed tree...

Accounting for spatial correlation of LiDAR model errors can improve the precision of model-based estimators. To estimate spatial correlation, sample designs that provide close observations are needed, but their implementation might be prohibitively expensive. To quantify the gains obtained by accounting for the spatial correlation of model errors, we examined (i) the spatial correlation patterns of residuals from LiDAR linear models developed to predict volume, total and stem biomass per hectare, quadratic mean diameter (QMD), basal area, mean and dominant height, and stand density and...

Whitebark pine (WBP, Pinus albicaulis) is a keystone species distributed widely at high elevations across western North America. It is in decline due to a combination of threats including infection from white pine blister rust (WPBR, caused by the non-native fungal pathogen Cronartium ribicola), mountain pine beetle (Dendroctonus ponderosae) predation, climate change, and altered fire regimes (Lintz et al. 2016, Smith et al. 2013, Tomback and Achuff 2010) (figs. 1, 2). Whitebark pine has been classified as Endangered on the latest IUCN Red List of Threatened Species (Mahalovich and Stritch...

National seed collection and gene conservation programs have expanded in recent years, especially in response to pressure from non-native pests such as the emerald ash borer (Agrilus planipennis). Since 2008, we have been working with the U.S. Department of Agriculture Agricultural Research Service (USDA ARS) and USDA Forest Service (USDA FS) leading seed collection efforts in the genus Fraxinus chiefly in Minnesota and North Dakota with smaller collections in Wisconsin and Iowa. Through 2015, we collected approximately 7.6 million seeds from a total of 1020 ash trees. The collections came...

Butternut (Juglans cinerea), a native tree species of eastern North America, is under serious threat from an introduced fungal pathogen (Ophiognomonia clavigignenti-juglandacearum), the agent of butternut canker disease. Butternut canker was first reported in North America in Wisconsin in 1967 and finally reached New Brunswick (NB) in 1997. The purpose of this study was to assess the health of NB butternut populations and develop a cryogenic ex situ conservation reserve of NB butternuts using part of the embryo isolated from nuts. We assessed a total of 425 trees in 25 populations for...

It is important to identify and protect at risk and sensitive tree species before irreparable damage occurs to their genetic base. Western cypress (Hesperocyparis spp.) is threatened by habitat loss and fragmentation, competition from nonnative species, and susceptibility to current fire intervals and intensities. In an effort to safeguard the western cypress species through ex situ gene conservation, the U.S. Department of Agriculture Forest Service collaborated with the Bureau of Land Management, U.S. Fish and Wildlife Service, California Department of Fish and Wildlife, California...

Species with small or disjunct populations, and those populations at the southern margin of a species’ range, are likely to be at higher risk from climate change. Two recent U.S. Department of Agriculture Forest Service (USDA FS) documents (Devine et al. 2012, Erickson et al. 2012) have advocated for ex situ genetic conservation of seed and evaluation of current seed inventories (including viability of older stored seedlots) for species and habitats most likely to be negatively impacted by the effects of climate change. Devine et al. (2012) ranked 57 widespread forest canopy species...

Because jack pine (Pinus banksiana Lamb.) is serotinous, it retains multiple years of cones until environmental conditions are favorable for releasing seed. These cones, which contain seed cohorts that developed under a variety of growing seasons, can be accurately aged using bud scale scars on twigs and branches. By calculating the average daily temperature for June through August for the past 15 years in Grand Rapids, Minnesota, and comparing them to the published 30 year average, we identified 3 years that could serve as a warmer (2005), cooler (2008) and control (2013) growing season...