Treesearch

Whitebark pine (Pinus albicaulis) (PIAL) is a proposed threatened species that plays a keystone ecological role in the Greater Yellowstone Ecosystem (GYE). Its population response to climate change is of high interest to managers because climate-induced declines may adversely affect critical ecosystem services that this species provides. While previous studies of reproductive size classes of the species have projected dramatic reductions in area of suitable habitat under climate warming scenarios, it has been suggested that the species can tolerate warmer and drier conditions if seedlings...

The interplay between top-down and bottom-up processes determines ecosystem productivity. Yet, the factors that mediate the balance between these opposing forces remain poorly understood. Furthering this challenge, complex and often cryptic factors like ecosystem engineering and trait-mediated interactions may play major roles in mediating the outcomes of top-down and bottom-up interactions. In semiarid grasslands of northeastern China, we conducted a large-scale, three-year experiment to evaluate how soil engineering by ants and plasticity in plants independently and jointly influenced...

Myrtle rust (MR) caused by Austropuccinia psidii is one of the most important diseases affecting eucalypt (Eucalyptus) plantations in Brazil. Over the years, selection and planting of MR-resistant clones has been the primary strategy for MR management. In May 2013, young trees of the GG100 hybrid (E. grandis × E. urophylla) clone - widely planted in Brazil and previously classified as resistant to MR - were infected by A. psidii in Minas Gerais, Brazil. In this study, artificial inoculations of a eucalypt clone set with differential reactions to A. psidii races were used to discover a new...

Forest growth processes are driven by site productivity and species functional traits, which are ultimately constrained by cumulative resource demand, resulting in competitive dynamics across successional forest communities. Historical efforts to quantify competition used density metrics or neighborhood crowding indices for yield modeling and reforestation surveys. These methods have expanded to include dendroclimatology and restoration applications that commonly assume similar competitive response across species of various functional types. We assessed the competitive indices of two focal...

Pyrolysis is the first step in a series of chemical and physical processes that produce flammable organic gases from wildland fuels that can result in a wildland fire. We report results using a new time-resolved Fourier transform infrared (FTIR) method that correlates the measured FTIR spectrum with an infrared thermal image sequence, enabling the identification and quantification of gases within different phases of the fire process. The flame from burning fuel beds composed of pine needles (Pinus palustris)and mixtures of sparkleberry, fetterbush, and inkberry plants was the natural heat...

Anurans often call in acoustically complex choruses, which can consist of multiple closely related species. Closely related sympatric species often differ in phenology and the acoustic properties of male advertisement calls, which, in some species, are phenotypically plastic. The tetraploid Eastern Gray Treefrog (Hyla versicolor) originates from multiple, separate hybridization events of the diploid Cope’s Gray Treefrog (Hyla chrysoscelis) with now-extinct diploid anurans. The two species are visually indistinguishable, exhibit highly similar ecology and behavior, and co-occur frequently...

As a signatory to the United Nations Framework Convention on Climate Change (UNFCCC), the United States has reported an economy-wide inventory of greenhouse gas (GHG) emissions and removals since the mid-1990s (U.S. EPA 2021). Forest land, harvested wood products (HWP), woodlands, and urban trees within the land sector collectively represent the largest net carbon (C) sink in the United States, offsetting more than 11 percent of total GHG emissions in 2019 (U.S. EPA 2021). Estimates of GHG emissions and removals are compiled by U.S. Department of Agriculture (USDA) Forest Service researcher...

Phosphites have been used to control Sudden Oak Death; however, their precise mode of action is not fully understood. To study the mechanism of action of phosphites, we conducted an inoculation experiment on two open-pollinated tanoak families, previously found to be partially resistant. Stems of treatment group individuals were sprayed with phosphite, and seven days later, distal leaves were inoculated with the Sudden Oak Death pathogen Phytophthora ramorum. Leaves from treated and untreated control plants were harvested before and seven days after inoculation, and transcriptomes of both...

1. Although most lotic ecosystems experience frequent and sometimes large disturbances, opportunities are uncommon to study primary succession in streams. Exceptions include new stream channels arising from events such as glacial retreat, volcanism, and catastrophic landslides. In 1980, the eruption and massive landslide at Mount St. Helens (WA, U.S.A.) created an entire landscape with five new catchments undergoing primary succession. We asked if riparian and lotic assemblages at early successional stages (36 years after the eruption) showed predictable change along longitudinal gradients...

Aim: Mangrove wetlands span broad geographical gradients, resulting in functionally diverse tree communities. We asked whether latitudinal variation, allometric scaling relationships and species composition influence mangrove forest structure and biomass allocation across biogeographical regions and distinct coastal morphologies. Location: Global. Time period: Present. Major taxa studied: Mangrove ecosystems. Methods: We built the largest field‐based dataset on mangrove forest structure and biomass to date (c. 2,800 plots from 67 countries) to address macroecological questions pertaining...