Digital record of specimens, including voucher material, from the study of a pollinator habitat restoration site under a commercial solar array in Jackson County, Oregon, 2019

Photovoltaic solar energy installation is booming, frequently near agricultural lands. Traditionally, the land underneath ground-mounted photovoltaic panels is unused, though some are repurposing it as habitat for pollinating insects. However, the impact of the solar panel canopy on the pollinator-plant community understory is unknown. In this study (Graham et al., 2020), we investigated the effects of solar arrays on plant composition, bloom timing and foraging behavior of pollinators in open fields (control), and in full shade and partial shade areas under solar panels in a predominant agricultural region of southern Oregon. Pollinating insect specimens were collected using hand nets, and identified to the lowest taxonomic group possible by M. Graham, A.R. Moldenke, and L.R. Best. A total of 85 voucher specimens were deposited into the Oregon State Arthropod Collection; accession record: OSAC_AC_2021_03_11_001-01

Taxonomic voucher specimens for study of post-wildfire forest habitat in Douglas County, Oregon

this publication provides data about voucher specimens deposited in the museum in conjunction with a research project on pollinators

Taxonomic voucher specimens for study of bee communities in intensively managed Douglas-fir forests in the Oregon Coast Range

Understanding how pollinators respond to anthropogenic land use is key to conservation of biodiversity and ecosystem services, but few studies have addressed this topic in coniferous forests, particularly those managed intensively for wood production. This study reports on voucher material generated as part of Zitomer et al. (2023), that assessed changes in wild bee communities with time since harvest in 60 intensively managed Douglas-fir (Pseudotsuga menziesii) stands in the Oregon Coast Range across a gradient in stand age spanning a typical harvest rotation (0-37 years post-harvest). We additionally assessed relationships of bee diversity and community composition to relevant habitat features, including availability of floral resources and nest sites, understory vegetation characteristics, and composition of the surrounding landscape. Specimens were collected using a combination of passive sampling methods-blue vane traps and white, blue, and yellow bowl traps- and hand-netting and were identified to the lowest possible taxonomic level by A.R. Moldenke and L.R. Best. Four hundred and ten taxonomic voucher specimens were deposited into the Oregon State Arthropod Collection (Accession# OSAC_AC_2023_01_09-001-01) to serve as a reference for future research

Wild bee diversity is enhanced by experimental removal of timber harvest residue within intensively managed conifer forest

The use of timber harvest residue as an energy source is thought to have environmental benefits relative to food-based crops, yet the ecological impact of this practice remains largely unknown. We assessed whether the abundance and diversity of wild bees (Apoidea) were influenced by the removal of harvest residue and associated soil compaction within managed conifer forest in western Oregon, USA. We sampled bees over two years (2014-2015) on study plots that were subjected to five treatments representing gradients in removal of harvest residue and soil compaction. We collected >7,500 bee specimens from 92 distinct species/morphospecies that represented five of the seven bee families. We trapped 3x more individuals in the second year of the study despite identical sampling effort in both years, with most trapped bees classified as ground-nesting species. Members of the sweat bee family (Halictidae) comprised more than half of all specimens, and the most abundant genus was composed of metallic green bees (Agapostemon, 33.6%), followed by long-horned bees (Melissodes, 16.5%), sweat bees (Halictus, 15.9%), and bumble bees (Bombus, 13.6%). In both years, abundance and observed species richness were greatest in the most intensive harvest residue treatment, with other treatments having similar values for both measures. Our study indicates that early successional managed conifer forest that has experienced removal of harvest residue can harbor a surprising diversity of wild bees, which are likely to have important contributions to the broader ecological community through the pollination services they provide

Pollination ecology within the Sierra Nevada

Volume: 42Start Page: 223End Page: 28

Habitat Structure and Prey Availability as Predictors of the Abundance and Community Organization of Spiders in Western Oregon Forest Canopies

Volume: 26Start Page: 203End Page: 22

13C and 15N in microarthropods reveal little response of Douglas‐fir ecosystems to climate change

Understanding ecosystem carbon (C) and nitrogen (N) cycling under global change requires experiments maintaining natural interactions among soil structure, soil communities, nutrient availability, and plant growth. In model Douglas‐fir ecosystems maintained for five growing seasons, elevated temperature and carbon dioxide (CO2) increased photosynthesis and increased C storage belowground but not aboveground. We hypothesized that interactions between N cycling and C fluxes through two main groups of microbes, mycorrhizal fungi (symbiotic with plants) and saprotrophic fungi (free‐living), mediated ecosystem C storage. To quantify proportions of mycorrhizal and saprotrophic fungi, we measured stable isotopes in fungivorous microarthropods that efficiently censused the fungal community. Fungivorous microarthropods consumed on average 35% mycorrhizal fungi and 65% saprotrophic fungi. Elevated temperature decreased C flux through mycorrhizal fungi by 7%, whereas elevated CO2 increased it by 4%. The dietary proportion of mycorrhizal fungi correlated across treatments with total plant biomass (n= 4, r2= 0.96, P= 0.021), but not with root biomass. This suggests that belowground allocation increased with increasing plant biomass, but that mycorrhizal fungi were stronger sinks for recent photosynthate than roots. Low N content of needles (0.8–1.1%) and A horizon soil (0.11%) coupled with high C : N ratios of A horizon soil (25–26) and litter (36–48) indicated severe N limitation. Elevated temperature treatments increased the saprotrophic decomposition of litter and lowered litter C : N ratios. Because of low N availability of this litter, its decomposition presumably increased N immobilization belowground, thereby restricting soil N availability for both mycorrhizal fungi and plant growth. Although increased photosynthesis with elevated CO2 increased allocation of C to ectomycorrhizal fungi, it did not benefit plant N status. Most N for plants and soil storage was derived from litter decomposition. N sequestration by mycorrhizal fungi and limited N release during litter decomposition by saprotrophic fungi restricted N supply to plants, thereby constraining plant growth response to the different treatments