Treesearch

Mangroves sequester large quantities of carbon (C) that become significant sources of greenhouse gases when disturbed through land‐use change. Thus, they are of great value to incorporate into climate change adaptation and mitigation strategies. In response, a global network of mangrove plots was established to provide policy‐relevant ecological data relating to interactions of mangrove C stocks with climatic, tidal, plant community, and geomorphic factors. Mangroves from 190 sites were sampled across five continents encompassing large biological, physical, and climatic gradients using...

Biological invasions are most practical to manage when invasive species population densities are low. Despite a potentially narrow window of opportunity for efficient management, managers tend to delay intervention because the cost of prompt action is often high and resources are limited. The Barred Owl (Strix varia) invaded and colonized the entire range of the Northern Spotted Owl (S. occidentalis caurina), but insufficient population data contributed to delays in action until the Barred Owl posed an existential threat to the Spotted Owl. The leading edge of the Barred Owl expansion has...

Broadband high-speed absorption spectroscopy using swept-wavelength external cavity quantum cascade lasers (ECQCLs) is applied to measure multiple pyrolysis and combustion gases in biomass burning experiments. Two broadly-tunable swept-ECQCL systems were used, with the first tuned over a range of 2089-2262 cm−1(4.42–4.79 µm) to measure spectra of CO2, H2O, and CO. The second was tuned over a range of 920-1150 cm−1(8.70–10.9 µm) to measure spectra of ammonia (NH3), ethene (C2H4), and methanol (MeOH). Absorption spectra were measured continuously at a 100 Hz rate throughout the burn process,...

Douglas-fir, Pseudotsuga menziesii(Mirb.) Franco, trees and stands can be protected from Douglas-fir beetle, Dendroctonus pseudotsugaeHopkins (DFB)-caused mortality by application of synthetic formulations of the beetle’s antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH). A biodegradable formulation of MCH, SPLAT MCH, was developed and evaluated for protecting individual Douglas-fir trees and small stands from colonization and mortality by DFB. In an individual-tree experiment in Idaho, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of treated trees...

This paper describes our initial evaluation of survival and performance of 14 species of trees being tested in Southern California's Inland and Coastal communities as part of the statewide Climate-Ready Trees study. Overall, 88% of all trees survived the first three years and survival rates for trees in reference sites (95%) were greater than for trees in parks (84%). Survival rates were higher in the Inland parks where growing conditions more closely matched the arid environments from which many of these species originated. Differences in species' survival rates and performance are...

Phytophthora pathogens are damaging native wildland vegetation including plants in restoration areas and botanic gardens. The infestations threaten some plants already designated as endangered and degrade high-value habitats. Pathogens are being introduced primarily via container plant nursery stock and, once established, they can spread to adjacent areas where plant species not previously exposed to pathogens may become infected. We review epidemics in California – caused by the sudden oak death pathogen PhytophthoraramorumWerres, De Cock & Man in ‘t Veld and the first USA detections of...

The walnut twig beetle, Pityophthorus juglandisBlackman (Coleoptera: Scolytidae), vectors the fungus Geosmithia morbida, which has been implicated in thousand cankers disease of walnut. Little is known about the flight behavior of the insect across seasons, or about the variability in its flight patterns with weekly fluctuations in weather. We sampled flying adults weekly over a 142-week period (from 29 August, 2011 to 2 June, 2014) with 12-unit black plastic multiple funnel traps baited with a male-produced aggregation pheromone in California, USA. Up to 5000 beetles were captured per...

This special issue of The Canadian Entomologist is dedicated to the memory of our colleague and friend, Dr. Steven J. Seybold (1959 -2019). Sadly, Dr. Seybold passed away unexpectedly 15 November 2019 while nearing completion of constructing the introduction to this special issue (Seybold and Fettig 2020).

Anthropogenic nitrogen (N) deposition is known to reduce plant diversity in ecosystems worldwide; however, effects on the diversity of Mediterranean‐type ecosystems—global hotspots of biodiversity—are relatively unexplored. In California, elevated N deposition due to air pollution has a multitude of ecological effects including the facilitation of nonnative plant invasion and altered ecosystem functioning, but impacts on plant richness have been inadequately quantified. We addressed this research gap by evaluating patterns of plant richness in coastal sage scrub (CSS), a severely threatened...