Treesearch

Establishing efficient functional genomic systems for creating and characterizing genetic variation in forest trees is challenging. Here we describe protocols for creating novel gene-dosage variation in Populus through gamma-irradiation of pollen, followed by genomic analysis to identify chromosomal regions that have been deleted or inserted in each F1 individual. Irradiated pollen is used in a controlled, interspecific cross to create F1 progeny that carry deletions and insertions of chromosomal regions. These insertions and deletions result in novel changes in gene dosage that in turn...

Landscape genetics has advanced the field of evolutionary ecology by providing a direct focus on relationships between landscape patterns and population processes, such as gene flow, selection, and genetic drift. This chapter discusses the current and emerging challenges and opportunities, which focus and facilitate future progress in the field. It presents ten conclusions drawn about the current state-of-the-art in landscape genetics. Landscape genomics is one way to fully grasp the various influences that landscape can have on neutral and adaptive genetic variation. A major challenge in...

Landscape genetic studies have focused on terrestrial animals more than any other taxonomic group. This chapter focuses on applications of landscape genetics for understanding connectivity of terrestrial animal populations. It starts with a general introduction covering unique characteristics and challenges of the terrestrial study system. This is followed by an overview of common research questions addressed in terrestrial animals using neutral markers in landscape genetics. These common research questions include detecting and defining barriers, identifying corridors, examining source-sin...

Elements of the natural world, such as mountains, rivers, and forests, are often seen as sacred in many cultural traditions. Recent conservation movements have even begun to draw on spiritual and religious beliefs to promote issues of environmental sustainability. The straightforward assumption in these cases is that sacred beliefs (compared with secular ones) will hold greater sway in alerting people to various environmental perils. However, environmental risk perception is a complex process, and we find that, in some cases, viewing natural resources as sacred may lead to a diminished...

Pacific Northwest forest managers seek estimates of post-timber-harvest woody residue volumes and biomass that can be related to readily available site- and tree-level attributes. To better predict residue production, researchers investigated variability in residue ratios, growing-stock residue volume per mill-delivered volume, across Idaho, Montana, Oregon, and Washington. This project presented unique sample design challenges, and the authors adopted model-based sampling to calculate the growing-stock logging residue ratio for the four-state region and produced models that relate the...

The woody stems of trees perceive gravity to determine their orientation, and can produce reaction woods to reinforce or change their position. Together, graviperception and reaction woods play fundamental roles in tree architecture, posture control, and reorientation of stems displaced by wind or other environmental forces. Angiosperms and gymnosperms have evolved strikingly different types of reaction wood. Tension wood of angiosperms creates strong tensile force to pull stems upward, while compression wood of gymnosperms creates compressive force to push stems upward. In this review,...

Submerged and emergent wetland plant communities are evaluated for their response to global climate change (GCC), focusing on seagrasses, submerged freshwater plants, tidal marsh plants, freshwater marsh plants and mangroves. Similarities and differences are assessed in plant community responses to temperature increase, CO2increase, greater UV-B exposure, sea level rise and other expected environmental alterations associated with GCC. Responses to most climate change variables are more similar within submerged plant communities, marine or freshwater, than between submerged vs. emergent...

Tree-killing bark beetles are major disturbance agents affecting coniferous forest ecosystems. The role of environmental conditions on driving beetle outbreaks is becoming increasingly important as global climatic change alters environmental factors, such as drought stress, that, in turn, govern tree resistance. Furthermore, dynamics between beetles and trees are highly nonlinear, due to complex aggregation behaviors exhibited by beetles attacking trees. Models have a role to play in helping unravel the effects of variable tree resistance and beetle aggregation on bark beetle outbreaks. In...

MCFire is a computer program that simulates the occurrence and effects of wildfire on natural vegetation, as a submodel within the MC1 dynamic global vegetation model. This report is a technical description of the algorithms and parameter values used in MCFire, intended to encapsulate its design and features a higher level that is more conceptual than the level provided by the computer source code, so that programmers and users can better understand its features and limitations. Two primary sources of the MCFire algorithms are the National Fire-Danger Rating System and CONSUME 3.0. MC1...

We evaluate the outcomes and consequences of a decade-long restoration project in a Hawaiian lowland wet forest as they relate to long-term management actions. Our initial study was designed both to promote native biodiversity and to develop knowledge that would enable land management agencies to restore invaded forests. Our premise of success followed the prevalent perception that short-term management, such as removal of invasive species, ideally translates into long-term and sustainable restoration. We were therefore disappointed and perhaps discouraged in our results—little recovery of...