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Keyword: resistance

Lick Creek: Lessons learned after 20+ years of fuel treatments in a ponderosa pine forest

Science Spotlights Posted on: September 08, 2020
Lick Creek is the longest running fuel treatment and restoration study of ponderosa pine forests in the northern U.S. Rocky Mountains. Through repeat photography and numerous published studies, we show how fuels and vegetation have changed over the 25 years since treatment and compare the effects of mechanical harvesting with and without prescribed burning.

Is three a crowd? The effect of stand density reduction on drought response

Science Spotlights Posted on: July 13, 2020
Three drought-tolerant tree species – Scots pine, sessile oak, and ponderosa pine – differ somewhat in their response to drought after stand density reductions. In this study, all species grew more each year on average when stand density was low rather than at maximum levels. Lower stand density reduced the drought susceptibility of Scots pine and sessile oak. Ponderosa pine, however, showed greater resistance and resilience to drought under higher, rather than lower, stand densities. Measures that reduce competition between trees are likely to help Scots pine and sessile oak adapt to a potentially drier and warmer climate, but such measures may have muted results compared to the effects of ponderosa pine’s adaptations to historically severely water-stressed conditions.

Implications of reduced stand density on tree growth and drought susceptibility: A study of three species under varying climate

Publications Posted on: June 20, 2020
A higher frequency of increasingly severe droughts highlights the need for short-term measures to adapt existing forests to climate change. The maintenance of reduced stand densities has been proposed as a promising silvicultural tool for mitigating drought stress. However, the relationship between stand density and tree drought susceptibility remains poorly understood, especially across ecological gradients.

Connecting variation in vegetation and stream flow: the role of geomorphic context in vegetation response to large floods along boreal rivers

Publications Posted on: March 04, 2020
1. Flooding governs riparian plant diversity along boreal rivers but the ecological role of extreme floods is only partly understood. We studied the dynamics of riparian plant composition and richness in the free-flowing Vindel River in northern Sweden, and the importance of reach type in sustaining high species richness. 2. We conducted three surveys of riparian plant species richness over a period of two decades.

Big trees, bark beetles, goshawks, and timber

Science Spotlights Posted on: August 21, 2019
Throughout the Rocky Mountains over the last century, large ponderosa pine trees provided lumber for growing cities and towns, along with fuel and timber for the mining and railroad industries. Most of these forests are now occupied by dense young and mid-aged forests highly susceptible to being killed by bark beetles and burned by wildfires. These conditions have been exacerbated by fire suppression and urban encroachment. As a result, knowledge is needed to inform management actions directed at restoring and conserving ponderosa pine forests. 

Integration and tradeoffs [Chapter 9]

Publications Posted on: August 14, 2019
Managing for sagebrush ecosystems that are resilient to disturbance and resistant to invasive plants often requires managers to make tough decisions in the face of considerable complexity and uncertainty. The decisionmaking environment is often characterized by multiple management objectives, limited management authority and capabilities, dynamic ecosystems and plant communities, and uncertain responses to management actions.

Wild horse and burro considerations [Chapter 8]

Publications Posted on: August 14, 2019
Wild horses (Equus caballus) and wild burros (E. asinus), like domestic livestock, can alter sagebrush ecosystem structure and composition and affect habitat quality for sagebrush dependent species (Beever and Aldridge 2011). The presence of Federally protected wild horses and wild burros can also have substantial effects on the capacity for habitat restoration efforts to achieve conservation and restoration goals.

Livestock grazing management [Chapter 7]

Publications Posted on: August 14, 2019
Part 1 of the Science Framework identifies livestock grazing as the most widespread land use in the sagebrush biome (Chambers et al. 2017a; hereafter, Part 1). In the Conservation Objectives Team Report (USDOI FWS 2013) improper livestock grazing is considered a present and widespread threat to Greater sage-grouse (Centrocercus urophasianus; hereafter, GRSG) for most GRSG populations.

Application of national seed strategy concepts [Chapter 6]

Publications Posted on: August 14, 2019
Native plant species are the foundation of sagebrush ecosystems and provide essential habitat for wildlife species, such as Greater sage-grouse (Centrocercus urophasianus; hereafter, GRSG).

Invasive plant management [Chapter 5]

Publications Posted on: August 14, 2019
One of the most significant stressors to the sagebrush biome is expansion and dominance of nonnative ecosystem-transforming species, particularly invasive annual and perennial plants.