Treesearch

Species distribution models, or SDMs, have become important decision support tools by answering fundamental questions about where species, including invasive species, are likely to survive and thrive based on environmental conditions. For an inexperienced modeller or model reviewer, the terminology and technical aspects of SDMs can be overwhelming, and even well-trained modellers can struggle to understand the implications of various modelling choices. Here, I outline some key considerations with respect to SDMs, focusing on their application to forest insects. Foremost, I assert that a...

1. The removal and exclusion of non-native ungulates for conservation of biodiversity is common globally, including on tropical Pacific Islands. However, the poorly quantified effects of ungulate exclusion on fuels and wildfire may represent an important conservation trade-off. 2. We measured fuels (live and dead fuel loads, type, height and continuity) and modelled potential wildfire behaviour (flame height and rate of spread) inside and outside of 13 ungulate exclosures, three of which received active ecological restoration (e.g. planting of native shrubs and trees), across a 2,740 mm...

Aim Habitat suitability modelling methods for presence-only species data are limited in their ability for making true predictions and are therefore often misused in ecological applications. A use-availability design—also known as a case–control design with contaminated controls—combines presence-only species data with a background sample of covariates where the species presence/absence is unknown. Assuming a log link function for the true probability of presence/absence, the use-availability data then can be analysed as a logistic regression model with a biased estimate of the intercept....

The FOrest Resource Outlook Model (FOROM) is a global recursive dynamic partial equilibrium model of the forest sector that recognizes Resources Planning Act (RPA) Assessment regions as separate producing, consuming, and trading market regions within a complete global market. FOROM is calibrated to a base year and projects future market variables of price, production, consumption, and trade of primary and secondary forest products across various socioeconomic developments. Further captured in the model are predicted changes in forest area and forest stocks (inventory volumes) by management...

Silvics of North America (SNA) is a widely used silvicultural manual. However, the last SNA was published in 1990. Therefore, 2,589 registered foresters were surveyed across four US states to answer two broad questions: (1) Should SNA be updated? And (2) would an updated SNA still be a useful tool for forest management? Most respondents indicated that the type and extent of content contained in the previous version of SNA was still desirable today. Aside from updating all sections with recent research findings, expansion was suggested for ecosystem services provided by species. An update...

The Budyko models provide a transparent framework for analyzing climate-catchment interactions and therefore have been widely used to quantify the role of vegetation influencing the partitioning of precipitation (P) into evapotranspiration (ET) and runoff (R) at watershed to regional scales under a changing environment. This study provides a thorough review of the use of Budyko models for answering modern hydrological questions including the relation between vegetation dynamic and catchment ET (or runoff) and climate change impacts on water balances. Our synthesis suggests that: When...

A critical step in the development of a postfire restoration strategy is the acquisition and analysis of relevant data and other information. This information is essential to answering questions posed in the postfire flowchart that, in turn, informs the restoration portfolio (both addressed in chapter 2). Spatially explicit information helps us to evaluate the ecological condition of a postfire landscape, including the capacity of a particular area to support ecosystems in the future and the ecological processes that may affect ecosystem succession. Acquired and analyzed at a meaningful...

Mixed-conifer forests are widely distributed throughout the mountainous regions of California, occurring just below the upper montane elevation belt and typically ranging from 1,000 to 7,000 ft (300 to 2000 m). Common tree species include ponderosa pine (Pinus ponderosa Lawson & C. Lawson) and Jeffrey pine (P. jeffreyi Balf.), white fir (Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.), sugar pine (P. lambertiana Douglas), incense cedar (Calocedrus decurrens (Torr.) Florin), Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), and black oak (Quercus kelloggii Newberry), and there are...

Chaparral is the dominant vegetation type on dry steep slopes of the national forests in southern California. Chaparral ecosystems are dominated by evergreen fire-adapted shrubs with the ability to recover after fire through fire-stimulated seed germination from a large dormant seed bank or resprouting from unburned root crowns. Despite the resilience of chaparral ecosystems to periodic fire, their integrity is challenged by high frequencies of human-ignited fires, which can occur before resprouting species renew their carbohydrate reserves or regenerating individuals (from seed) reach...

Widespread yet vulnerable, sagebrush (Artemisia spp.) steppe ecosystems provide a variety of biological, hydrological, and recreational ecosystem services throughout the Interior West (Homer et al. 2015). One particular service is the provision of essential habitat for the greater sage-grouse (Centrocercus urophasianus), which was considered for listing under the Endangered Species Act. That listing was avoided in 2015 by an unprecedented conservation partnership across organizations and state boundaries (Chambers et al. 2017). The once widespread sagebrush steppe ecosystem has been...