Treesearch

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. Resource decisionmakers must be able to determine appropriate objectives based on desired management outcomes and sort through the different management considerations...

Monitoring programs designed to track ecosystem changes in response to both stressors and disturbances use repeated observations of ecosystem attributes. Such programs can increase our understanding of how interactions among resilience to disturbance, resistance to invasive species, and “change agents” including management actions influence resource conditions (or status) and trends and outcomes of conservation and restoration actions. This type of monitoring information provides the basis for adaptive management. The overarching goal of an integrated monitoring and adaptive management...

Management actions that enable adaptation to climate change and promote resilience to disturbance are becoming increasingly important in the sagebrush biome. In recent decades temperatures have increased, growing seasons have lengthened, and in many areas the timing and amount of precipitation has changed (Chambers et al. 2017 [hereafter, Part 1], section 4; Kunkel et al. 2013a,b,c). Global climate change models are used to project future changes in temperature and precipitation based on relative concentration pathways of likely emissions of carbon dioxide (CO2) and other trace gases and...

The Science Framework is part of an unprecedented conservation effort underway across 11 States in the western United States to address threats to sagebrush (Artemisia spp.) ecosystems and the species that depend on them. Sagebrush ecosystems provide a large diversity of habitats and support more than 350 species of vertebrates (Suring et al. 2005). These ecosystems currently make up only about 59 percent of their historical area, and the primary patterns, processes, and components of many sagebrush ecosystems have been significantly altered since Euro-American settlement in the mid-1800s...

Scientists and managers initiated a collaborative process to assist the Rio Grande National Forest (RGNF) with bringing climate change information into its Forest Planning Process. The first objective of the collaborative, 2-day workshop was to present and discuss in a workshop format the salient climate change science for the RGNF landscape, in terms of projections, impacts, and vulnerabilities. The second objective was to facilitate a planning process that would stimulate ideas regarding aspects of current and proposed management that may need modification in light of stressors related...

Altered fire regimes can drive major and enduring compositional shifts or losses of forest ecosystems. In western North America, ponderosa pine and dry mixed-conifer forest types appear increasingly vulnerable to uncharacteristically extensive, high-severity wildfire. However, unburned or only lightly impacted forest stands that persist within burn mosaics - termed fire refugia - may serve as tree seed sources and promote landscape recovery.We sampled tree regeneration along gradients of fire refugia proximity and density at 686 sites within the perimeters of 12 large wildfires that...

Context: Fire regimes in many dry forests of western North America are substantially different from historical conditions, and there is concern about the ability of these forests to recover following severe wildfire. Fire refugia, unburned or low-severity burned patches where trees survived fire, may serve as essential propagule sources that enable forest regeneration. Objectives To quantify the influence of fire refugia spatial pattern and other biophysical factors on the process of post-fire tree regeneration; in particular examining both the proximity and density of surrounding refugia...

Ruil (Nothofagus alessandrii) is an endangered keystone species from the Mediterranean climate zone of Chile. Ruil’s fragile state of conservation urges development of restoration programs, but specific protocols for nursery production and field establishment that ensure plant survival are largely unknown. Therefore, we examined the effect on nitrogen (N) fertilization and container size during nursery production in combination with the use of mesh shelters after outplanting on survival and growth during the first growing season in the field. First year outplanting survival of nursery-grown...

We excavated the root systems of Pinus ponderosa trees growing on a steeply sloped, volcanic ash-influenced soil in the northern Rocky Mountains of the United States to assess their functional coarse-root traits and root system architecture. Trees, outplanted as one-year-old seedlings from a container nursery, were in their 32nd growing season on the site. We found that the trees had deployed more roots, in terms of length and volume, in the downslope and windward quadrants than in their upslope and leeward quadrants, likely a response to mechanical forces toward improving stability....

Wildland fire is an understudied yet highly important disturbance agent on the Indian subcontinent. In particular, there is uncertainty regarding the degree to which annual climate variation influences inter-annual variability in fire activity. In this study, we evaluate wildland fire at two complementary spatial scales in the southern portion of the Western Ghats mountain range (hereafter ‘Western Ghats’) in India. At the larger regional scale, we evaluate temporal and spatial variability in fire activity from 2001 to 2015. At the smaller scale, we evaluate the relationship between annual...