Treesearch

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...

Facing a Challenge Non-native diseases and insects as well as a changing climate pose serious threats to native trees in North America. Genetic variation in a species is key to its enduring persistence in the face of these abiotic and biotic threats. Efforts to conserve genetic diversity of North American tree at-risk species will ensure the genetic resources of a species are available to help foster management activities to preserve tree species in native and urban forests, retain their invaluable roles in providing ecosystem services, and commercial and cultural uses. One species facing...

Challenge Port-Orford-cedar (POC) (Chamaecyparis lawsoniana) is a long-lived conifer native to southwest Oregon and northwest California, occurring from sea level to above 1500 m (5085 ft). It is a foundational species in its native ecosystems and is used world-wide horticulturally. A non-native pathogen, Phytophthora lateralis, cause of Port-Orford-cedar root disease, has caused high mortality in native forest ecosystems and ornamental plantings (Betlejewski et al. 2011). The presence of P. lateralis has limited the use of POC in managed plantations and urban forests. There is concern...

Kentucky coffeetree, Gymnocladus dioicus, is a picturesque shade tree adaptable to urban conditions and drought, with no serious insect or disease problems. These traits make G. dioicus a promising candidate among diverse tree genera to replace ash (Fraxinus) trees affected by the emerald ash borer (Agrilus planipennis) or oaks (Quercus) being affected by oak wilt (caused by the fungus Ceratocystis fagacearum) within our cities. In nature, Kentucky coffeetree comprises only a small percentage of forested systems across the Midwest, warranting the assembly of an ex situ germplasm collection....

Quercus oglethorpensis (Oglethorpe oak) is an endangered species native to the southeastern United States. It is threatened by land use changes, competition, and chestnut blight disease caused by Cryphonectria parasitica. The species is distributed sparsely over a linear distance of ca. 950 km. Its range includes several disjunct populations potentially harboring unique genetic diversity or adaptive variation. Protected populations in the Bienville National Forest (Mississippi), Oconee National Forest (Georgia), and Sumter National Forest (South Carolina) are regularly monitored and...

Changing climate and declining forest populations imperil the future of certain forest tree species. To complement forest management and genetic conservation plans, we propose a new paradigm for seedling seed orchards: foster genetic mixing among a variety of seed sources to increase genetic diversity and adaptive potential of seed supplies used for forest restoration. This new type of seed orchard, a restoration seed reserve (RSR) targeting imperiled species, would incorporate into seed production the seed transfer concepts of assisted gene flow and composite provenancing (Aitken and...