Treesearch

Many forests in dry mountain regions are characterized by a lower elevational treeline. Understanding the controls on the position of lower treeline is important for predicting future forest distributional shifts in response to global environmental change. Lower treelines currently at their climate limit are expected to be more sensitive to changing climate, whereas lower treelines constrained by non-climatic factors are less likely to respond directly to climate change but may be sensitive to other global change agents. In this study, we used existing vegetation classifications to map...

The wildland–urban interface (WUI) occurs at the intersection of houses and undeveloped wildlands, where fire is a safety concern for communities, motivating investment in planning, protection, and risk mitigation. Because there is no operational definition of WUI based on where fires in fact have occurred, I used fire occurrences to objectively establish a definition of WUI, while examining spatiotemporal changes, for the conterminous United States. I applied four classifiers, but focused on C5.0, which produced equivalent sensitivity (0.87 to 0.91 at prevalence = 0.67) and generated a...

Pre-Euro-American settlement vegetation provides information about historical ecology. I evaluated baseline conditions and novel status of current forests in Michigan using historical (1836 to 1858) and current (2010–2015) surveys and assessed quantitative and qualitative measures of novel status. Aspen (increased from 2% to 11% of all trees) and red maple (<2% to 12.5%) replaced eastern hemlock (15% to 2%) and American beech (8% to <1%) as most abundant species. Density was similar between surveys but mean diameter (trees ≥12.7 cm) decreased from 39 to 22 cm. The emerging forest type is a...

The Fire Continuum Conference, co-sponsored by the Association for Fire Ecology and the International Association of Wildland Fire, was designed to cover both the biophysical and human dimensions aspects of fire along the fire continuum. This proceedings includes many of topics covered during the conference - including pre-fire planning and management, strategies during an incident, and post-fire effects and management options. It contains extended abstracts and full papers based on some of the presentations as well as field trips.

Looking into the past can help biologists and managers determine what is possible in the future. New research is helping understand the past and more accurately estimate future salmon recovery potential. Central Idaho’s Middle Fork Salmon River (MFSR) offers a glimpse of historical Chinook salmon (Oncorhynchus tshawytscha) spawning and rearing habitat. The MFSR flows through the Frank Church River of No Return Wilderness, where natural processes remain intact and human influences are minimal. “It’s a very unique system that supports critical habitat for many native species,” says Russ...

The role of genetics in ecosystem restoration has largely revolved around the policy of using local genotypes (i.e., those sourced from areas near the restoration site), based on the logic that local plants are best adapted to local conditions (Johnson et al. 2004; Meffe and Carroll 1977). In a relatively stable environment, this is a sound practice; however, global environmental change impacts on the landscape are increasingly rendering this policy as inadequate at best and damaging at worst (Whitham et al. 2010). Here we define “global change” as ongoing changes in temperature, moisture,...

Terrestrial fluvial-riparian ecosystems (FREs) are riverine landscapes that integrate aquatic, riparian, and upland domains within watersheds, linking physical, biological, and cultural-economic processes (Tockner et al. 2002). FRE characteristics and processes intergrade through the entire watershed, from the river’s headwaters to its terminus into an endorheic basin or the sea, and can extend far out into the submarine environment (e.g., Canals et al. 2009; Vannote et al. 1980; Ward et al. 2018; fig. 10). FREs include all sources of water that contribute to the basin’s riverine ecosystem,...

An abundance of information, some of which is included in other chapters in these volumes, documents and laments the historic loss of or changes to riparian ecosystems. Historic impacts to most riparian organisms, ranging in size from cottonwood trees to microbes, are fairly well documented. Causes of these changes are also well documented or speculated upon based on the best available information. It is clear that the world, and specifically the riparian world, has changed because of human activities. It appears likely that changes will continue to occur as human activities continue, and...

The evolution of our modern-day understanding of riparian ecology and the development of the field of riparian ecosystem/habitat restoration underwent significant advances from 1970 to 2000. The four parts of this chapter include: (1) a chronological overview of the major activities, events and publications that documented, and punctuated, the progress of our understanding of riparian ecology and riparian ecosystem restoration in California; (2) a discussion of the various types of riparian restoration projects with the projects categorized by the primary reason they were undertaken; (3)...

The Great Central Valley of California occupies 22,500 square miles (58,000 square kilometers) in the interior of northern and central California. At the time of the Gold Rush in 1849, nearly 1 million acres (1,600 square miles, 4,000 square kilometers) of riparian vegetation covered the Central Valley floor along with approximately an equal area of wetlands. The riparian area flourished in the large river basins and along river channels (Katibah 1984; Thompson 1961). The Central Valley is partly defined by the Sacramento River in the north, the San Joaquin River in the south, and the...