Treesearch

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...

The Missouri Botanical Garden’s living collections are critical for supporting its multi-disciplinary strategy of integrated plant conservation. The Garden is increasing ex-situ collections of plants in need of conservation to build species diversity into its displays for visitor education. Current areas of focus include native Missouri species and International Union for Conservation of Nature and Natural Resources (IUCN) Red Listed genera from around the world. Several key projects support this initiative. These include development of a Living Collections Management System (LCMS),...

Red spruce’s (Picea rubens Sarg.) range extends from the southern and central Appalachians north into Vermont and Maine and then to the Canadian Maritime provinces with relic populations as far west as Ontario. Due to heavy logging and resultant severe fires in the 19th and early 20th centuries, and more recent declines related to air pollution and invasive pests, the amount of red spruce is now less than five percent of its former prevalence in the southern and central part of its range and these populations are highly fragmented. As a montane species over much of its range, it also has a...

Short-term studies show that American chestnut (Castanea dentata) grows faster on mesic compared to xeric sites. Long-term impacts of site quality and corresponding moisture and nutrient availability on backcross chestnut establishment success and resistance to the chestnut blight fungus, Cryphonectria parasitica, however, have not been evaluated. We report here the first year results from a study designed to evaluate the effects of three site quality treatments—mesic, xeric, and intermediate—on the establishment success and blight resistance of chestnut seedlings planted on the Allegheny...

Species and populations of forest trees stressed by a rapidly changing climate must adjust or they will not survive. Loss of species and populations could occur if they lack the genetic variability to adapt, the capacity to migrate to suitable habitats, or the ability to adjust to new environments through phenotypic plasticity. Fortunately, many forest tree provenance studies were established in the 20th century across the United States. Most of the studies were initiated or funded by the United States Department of Agriculture (USDA). Many of these plantations are now over a half-century...

Provincial tree improvement programs in Alberta began in 1976. Early gene conservation focused on ex situ measures such as seed and clone banking, and research trials of commercial species with tree improvement programs. The gene conservation program now encompasses representative and unique populations of all native tree species in situ. The ex situ program aims to capture representative samples of each species by natural subregion combination in the provincial seed archive. Species whose seeds do not store well may be represented in clone banks, but resources limit those archives to...