Treesearch

In this final chapter we briefly look back over what we have attempted in this book, and then look toward the future to discuss the outlook for overcoming the challenges we face within our fields of ecological science and in the greater application of this knowledge to enhance the prospect for a sustainable future for the biosphere. Looking back, we have tried to present a view of ecological science at the cusp of major change. The change is all around us, driven by vast improvements in computational power, analytical tools, spatial databases, economy and related governance structures...

The non-native fungus Cronartium ribicola, that causes white pine blister rust (WPBR), is impacting or threatening limber pine, Pinus flexilis, and Rocky Mountain bristlecone pine, Pinus aristata. In the Southern Rockies, where the rust invasion is still expanding, we have the opportunity to be proactive and prepare the landscape for invasion. Genetic resistance to WPBR is essential to the future of pine populations given the lethality of the disease and its continued spread. Options for increasing the frequency of resistance in a stand includes (1) supplementing resistance by outplanting...

This paper offers a preliminary investigation into the conditions under which it might be optimal to engage in proactive management of a non-timber forest resource in the presence of an invasive species whose spread is unaffected by management action. Proactive management is defined as treating an uninfected area in order to encourage healthy ecosystem function, given that the arrival of the invasive is inevitable. Inspired by the problem of white pine blister rust in the Rocky Mountain west, the model was solved under varying assumptions concerning the scale of management action, benefit...

White pine blister rust is an exotic, invasive disease of white, stone, and foxtail pines (also referred to as white pines or five-needle pines) in the genus Pinus and subgenus Strobus (Price and others 1998). Cronartium ribicola, the fungus that causes WPBR, requires an alternate host - currants and gooseberries in the genus Ribes and species of Pedicularis and Castilleja (McDonald and others 2006, Zambino and others 2007) - to complete its life cycle. White pine blister rust was discovered in western North America in 1921. It is thought that the disease was accidentally introduced on...

Limber Pine (Pinus flexilis) populations in the southern Rock Mountains are severely threatened by the combined impacts of mountain pine beetles and white pine blister rust. Limber pine’s critical role these high elevation ecosystems heightens the importance of mitigating impacts. To develop forest-scale planting methods six seedling planting trial sites were installed extending from the Medicine Bow Nation Forest in southern Wyoming to the Great Sand Dunes National Park and Preserve in southern Colorado

Limber pines are widely distributed across the Rocky Mountains and are especially important because of their unique cultural and ecological characteristics. Recent surveys have suggested that significant ecological impacts are occurring as a result of white pine blister rust (WPBR) and other damaging agents. Additionally, several new WPBR infestations have been discovered in Colorado and the disease front in northern Colorado is within 6 miles of Rocky Mountain National Park. Past studies have provided critical information on the distribution and intensity of the disease, but we have...

Straw mulch application after high severity wildfire has gained favor in recent years due to its efficacy in reducing soil erosion hazards. However, possible collateral effects of mulching on post-fire vegetation recovery have received relatively little study. We assessed mulching effects on plant cover and species richness, tree seedling establishment, and exotic species densities in the second year following the 2006 Tripod Wildfire in north-central Washington State, USA, by observing vegetation responses to spatial variability in mulch cover and depth. Mulch cover averaged about 35%,...

Canada lynx are listed as a threatened species in the contiguous US. Understanding the reproductive characteristics (i.e., mating system, behavior, physiology) of a species is useful for ensuring effective in situ and ex situ management plans. The goal of this study was to describe patterns of androgen expression in both captive and wild male Canada lynx using fecal hormone metabolite analysis. Among captive lynx, juvenile and castrated males had lower concentrations of fecal androgens (fA) than intact males, thereby demonstrating that the assay detects biologically meaningful differences...

Canada lynx face some unique breeding restrictions, which may have implications for population viability and captive management. The goal of this study was to improve our understanding of basic reproductive physiology in Canada lynx. Using fecal hormone metabolite analysis, we established normative patterns of fecal estrogen (fE) and progestagen (fP) expression in captive and wild female Canada lynx. Our results indicate that Canada lynx have persistent corpora lutea, which underlie their uncharacteristic fP profiles compared to other felids. Thus, fP are not useful for diagnosing pregnancy...

We investigated seasonal patterns in resource selection of Canada lynx (Lynx canadensis) in the northern Rockies (western MT, USA) from 1998 to 2002 based on backtracking in winter (577 km; 10 M, 7 F) and radiotelemetry (630 locations; 16 M, 11 F) in summer. During winter, lynx preferentially foraged in mature, multilayer forests with Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) in the overstory and midstory. Forests used during winter were composed of larger diameter trees with higher horizontal cover, more abundant snowshoe hares (Lepus americanus), and...