Treesearch

Interspecific hybridization plays a key role in the evolution of novel fungal pathogens, and when it occurs between native and invasive species, can lead to potentially serious consequences. In this study, we examined the temporal and spatial distribution of a recently detected hybrid (Cronartium x flexili) of two tree pathogens, invasive to North America Cronartium ribicola and native Cronartium comandrae. In total, 726 and 1452 aecia from 178 Pinus contorta ssp. latifolia and 357 Pinus flexilis trees were collected from 26 sites in four national forests in 2019–2021. Using morphological...

The High-5 comprise a subset of a unique group of related white pine species in the subgenus Strobus that grow across the high mountains of western North America. They include whitebark pine (Pinus albicaulis), limber pine (P. flexilis), southwestern white pine (P. strobiformis), Rocky Mountain bristlecone pine (P. aristata), Great Basin bristlecone pine (P. longaeva), and foxtail pine (P. balfouriana) (Fig. 1). These species grow in small groups on ridges as well as components of extensive forest communities. They have a disproportionally large effect on ecosystem functioning and biodivers...

Since the development of contemporary stocking techniques a century ago, the combination of climatic, atmospheric, financial, and social factors that determine forest management strategies have changed, altering aspen stand dynamics in the western Great Lakes, USA. Despite this, aspen management is still informed by 1970s management guides that are based on 1920s inventories; hence, a century exists between the data that underlie current management guidelines and current stand conditions. We hypothesized that current aspen stands may support higher stocking and height growth than nearly a...

Researchers have debated the relative importance of environmental versus Indigenous effects on past fire regimes in eastern North America. Tree-ring fire-scar records (FSRs) provide local-resolution physical evidence of past fire, but few studies have spatially correlated fire frequency from FSRs with environmental and anthropogenic variables. No study has compared FSR locations to Native American settlement features in the eastern United States. We assess whether FSRs in the eastern US are located near regions of past Native American settlement. We also assess relationships between...

Round timber and wood products are measured, sorted, and graded at different stages in the wood-value chain starting already at the stem level in the forest. This chapter gives an overview of grading methodologies and techhniques for the measurement and grading of round timber, sawn timber, veneer, and wood-panel products. The section concerning round timber focuses on the grading and sorting of logs for sawmill and veneer production. For sawn timber, visual and strength grading are discussed, for both the European and the North American markets. Techniques for measurement and process...

Planted forests are an integral part of life for rural and urban communities throughout the United States of America. Beyond wood and wood products, these forests provide essential ecosystem services such as healthy soils, clean and abundant water, and carbon sequestration, while also enhancing livelihoods for producers and consumers (Caputo and Butler, 2017; Domke et al., 2020; Liu et al., 2022).

Climate projections predict higher temperatures and more frequent hurricanes in the tropics. Tropical plants subjected to these stresses may respond by acclimating their physiology. We investigated tropical forest root respiration in response to in situ experimental warming and hurricane disturbance in eastern Puerto Rico. We measured mass-normalized root specific respiration, root biomass, and root traits at the Tropical Responses to Altered Climate Experiment (TRACE), where understory vegetation is warmed + 4 °C above ambient. Our measurements span 5 years, including before and after two...

Freshwaters require targeted policy considerations to achieve biodiversity conservation goals and to support ecosystem services that communities around the globe depend upon. Effective conservation requires creative solutions that build and expand upon conventional protected areas, contextualized for these diverse ecosystems. Global recognition of the need for protection targeting inland waters has lagged behind protections for marine and terrestrial ecosystems, likely contributing to the greatest biodiversity losses occurring among freshwater species1. In December 2022, at the Convention...

Recent stream restoration approaches, such as Stage 0 restoration, aim to restore natural processes to regain lost ecosystem functions, but project implementation can also represent a reach-scale disturbance. Assumed outcomes of these restoration actions, like greater biological productivity, are rarely evaluated. In this study, we examined the short-term effects of Stage 0 floodplain restoration on the secondary production of aquatic macroinvertebrate communities in the South Fork McKenzie River, Oregon, 1–2 years following project implementation. We seasonally sampled macroinvertebrates...