Treesearch

If the climate changes faster than the adaptation or migration capability of plants (Zhu et al. 2012; Gray and Hamann 2013), foresters and other land managers will face an overwhelming challenge. Growing trees that survive may become more important than growing perfectly formed trees (Hebda 2008) and may require selection of adapted plant materials and/or assisting the migration of plant populations (Peters and Darling 1985). Agencies, land managers, and foresters are being advised to acknowledge climate change in their operations, but current client demands, policies, and uncertainty...

The direct effects of climate change on alpine treeline ecotones – the transition zones between subalpine forest and non-forested alpine vegetation – have been studied extensively, but climate-induced changes in disturbance regimes have received less attention. To determine if recent increases in area burned extend to these higher-elevation landscapes, we analysed wildfires from 1984–2012 in eight mountainous ecoregions of the Pacific Northwest and Northern Rocky Mountains. We considered two components of the alpine treeline ecotone: subalpine parkland, which extends upward from subalpine...

Seeds of native plants are needed for rangeland restoration in the Intermountain West. Many of these plants are rarely cultivated and relatively little is known about the cultural practices required for their seed production. Irrigation trials were conducted for five perennial Lomatium species over multiple years. Lomatium species grown at the Oregon State University Malheur Experiment Station, Ontario, OR received 0, 100, or 200mmof irrigation per year. Seed yield responses to irrigation were evaluated by linear and quadratic regression. In general, seed yields from the three species...

This study established that chilling removes primary seed dormancy in 2 rare penstemons of the western US, Gibbens’ beardtongue (Penstemon gibbensii Dorn [Scrophulariaceae]) and blowout penstemon (Penstemon haydenii S. Watson). Wild-harvested seeds were subjected either to moist chilling at 2 to 4 °C (36-39 °F) for 0, 4, 8, 12, and 16 wk or to approximately 2 y of dry storage. Seeds of both species were dormant at harvest and responded positively to chilling. Penstemon gibbensii germination increased linearly with length of chilling, and collections from sites with longer winters required...

Landscape connectivity between protected areas is crucial for the conservation of megafauna. But often, corridor identification relies on expert knowledge that is subjective and not spatially synoptic. Landscape analysis allows generalization of expert knowledge when satellite tracking or genetic data are not available. The Nilgiri Biosphere Reserve in southern India supports the largest wild populations of the endangered Asian elephant Elephas maximus. Current understanding of connectivity in this region is based on corridors identified by experts, which are not empirically validated and...

Wildland fire management has reached a crossroads. Current perspectives are not capable of answering interdisciplinary adaptation and mitigation challenges posed by increases in wildfire risk to human populations and the need to reintegrate fire as a vital landscape process. Fire science has been, and continues to be, performed in isolated "silos," including institutions (e.g., agencies versus universities), organizational structures (e.g., federal agency mandates versus local and state procedures for responding to fire), and research foci (e.g., physical science, natural science, and...

The Fire Severity Mapping System (FIRESEV) project is an effort to provide critical information and tools to fire managers that enhance their ability to assess potential ecological effects of wildland fire. A major component of FIRESEV is the development of a Severe Fire Potential Map (SFPM), a geographic dataset covering the contiguous United States (CONUS) that quantifies the potential for wildland fires to burn with higher severity should they occur (Dillon et al 2011a). We developed this map using empirical observations and statistical models to relate biophysical conditions at the...

The 'Spring Dip' in conifer live foliar moisture content (LFMC) has been well documented but the actual drivers of these variations have not been fully investigated. Here we span this knowledge gap by measuring LFMC, foliar chemistry, foliar density and foliar flammability on new and old foliage for an entire year from both Pinus resinosa (red pine) and Pinus banksiana (jack pine) at a site in Central Wisconsin. We found that needle dry mass increased by up to 70% in just three weeks and these increases were manifested as strong seasonal variations in foliar moisture content and foliar...

Scientists and managers critically need ways to assess how fuel treatments alter fire behavior, yet few tools currently exist for this purpose.We present a spatially-explicit-fuel-modeling system, FuelManager, which models fuels, vegetation growth, fire behavior (using a physics-based model, FIRETEC), and fire effects. FuelManager's flexible approach facilitates modeling fuels across a wide range of detail. Large trees or shrubs with specific coordinates are modeled as individual "Plants", while understory plants are modeled as collections of plants called "LayerSets". Both Plants and...

Wildland fires propagate by liberating energy contained within living and senescent plant biomass. The maximum amount of energy that can be generated by burning a given plant part can be quantified and is generally referred to as its heat content (HC). Many studies have examined heat content of wildland fuels but studies examining the seasonal variation in foliar HC among vegetation types are severely lacking. We collected foliage samples bi-weekly for five months from two common species in the western USA: lodgepole pine (Pinus contorta Douglas ex Loudon) and big sagebrush (Artemisia...