Treesearch

In response to climate warming, subalpine treelines are expected to move up in elevation since treelines are generally controlled by growing season temperature. Where treeline is advancing, dispersal differences and early life stage environmental tolerances are likely to affect how species expand their ranges. Species with an establishment advantage will colonize newly available habitat first, potentially excluding species that have slower establishment rates. Using a network of plots across five mountain ranges, we described patterns of upslope elevational range shift for the two dominant...

We question the growth arrestment hypothesis for bow stave removal used by indigenous people in the western Great Basin. Using modern understanding of tree growth and wound response, we suggest that growth would not be arrested by one or two transverse notches along a juniper stem. Rather these would trigger compartmentalization, which limits cambial death to within 10 cm of the wound, and wound closure. Seasoning on the stem, as suggested by the hypothesis, would not occur as 90% of the cambium between the notches would remain alive. Further, wound closure growth ("wound wood") is...

Over the last century, significant declines in rainfall across the state of Hawai‘i have been observed, and it is unknown whether these declines are due to natural variations in climate, or manifestations of human-induced climate change. Here, a statistical analysis of the observed rainfall variability was applied as first step towards better understanding causes for these long-term trends. Gridded seasonal rainfall from 1920 to 2012 is used to perform an empirical orthogonal function (EOF) analysis. The leading EOF components are correlated with three indices of natural climate variations...

Coast redwood (Sequoia sempervirens (D. Don) Endl.) seedlings were grown from seed in controlled environments with 16 hour photoperiods using three light patterns that mimicked full shade (constant light level), intermittent high light such as long duration sun flecks (low light with 15 minutes of intense light every 2 hours), and large openings (4 hours low light, 8 hours high light, 4 hours low light). Each light pattern contained three light intensity levels (33 percent, 66 percent, and 100 percent) with one intensity level in each pattern that provided 5.1 daily light integral (DLI)....

To better understand the distribution and current structure of coast redwood (Sequoia sempervirens (D.Don) Endl.) forests throughout the range and how it varies by land ownerships, the Save the Redwoods League has conducted a redwood specific analysis of a high resolution forest structure database encompassing the entire natural coast redwood range. Using this analysis, we are able to identify those areas most likely to contain coast redwood and the probable stature of those forests. Previous League databases were built by expert evaluation of aerial photographs, requiring substantial time...

In 2013, redwood (Sequoia sempervirens (D.Don) Endl.) was listed as endangered under the International Union of Conservation of Nature (IUCN) Red List. While this listing has no political or legal consequences for the management of redwood, it could have economic consequences as land and mill owners of the redwood region have sought to link redwood to sustainable practices in the marketplace. This paper argues that the listing of redwood, however, is fundamentally flawed by the metrics of the Red List, and that the listing misses the chief conservation challenges related to redwood, which...

Cannabis (Cannabis sativa or C. indica) agriculture is a multi-billion dollar industry in the United States that is changing rapidly with policy liberalization. Anecdotal observations fuel speculation about associated environmental impacts, and there is an urgent need for systematic empirical research. An example from Humboldt County, California, a principal cannabis-producing region, involved digitizing 4,428 grow sites in 60 watersheds with Google Earth imagery. Grows were clustered, suggesting disproportionate impacts in ecologically important locales. Sixty-eight percent of grows were...

Amenity values, development potential, commodity prices and productive capacity largely determine rural land prices. For rural lands used in timber and agricultural production, capacity and expected future commodity prices play primary roles. For rural lands that are used as second homes or recreational properties, amenities— such as being near lakes or having scenic views—drive pricing. Here, we examine the impact of cannabis production on rural property values in Humboldt County, California, the largest cannabis producing county in the country and also home to both productive and...

California’s cap-and-trade carbon market has included forest offset projects, available to all private landowners across the United States. The redwood region has been at the forefront of the market, creating the earliest forest carbon projects. From carbon registries, we compiled a database of all forest carbon projects in the market, in order to determine where projects were located, what types of landowners (e.g. industrial, non-industrial, tribal, timber investment management organizations [TIMO]) were participating, and how projects were being developed. Notably, non-industrial...