Treesearch

This field guide - designed for use by people with minimal botanical training - is an identification aid for nearly 200 plant species having ecological indicator value in northern Idaho forest habitat types. It contains line drawings, simplified taxonomic descriptions, characteristics, tables, conspectuses, and keys. It emphasizes characteristics useful for field identification of many common and special interest plants. This is not a comprehensive taxonomy of northern Idaho flora.Previous Versions:RMRS-GTR-118-CD (2004): https://research.fs.usda.gov/treesearch/65151INT-GTR-180: https://res...

The spruce beetle has been observed attacking spruce aphid-defoliated trees, although whether spruce beetle attacks are facilitated by spruce aphid defoliation is uncertain. The potential for spruce aphid to incite spruce beetle outbreaks is of great concern for managers as spruce populations are already declining across the West and spruce aphid outbreaks may increase with warmer winters. No previous studies have investigated impacts of spruce aphid defoliation on spruce beetle performance or defenses of Engelmann spruce. This project addressed impacts of spruce aphid defoliation on...

Recent increases in woody plant density in dryland ecosystems - or “woody encroachment”- around the world are often attributed to land-use changes such as increased livestock grazing and wildfire suppression or to global environmental trends (e.g., increasing atmospheric carbon dioxide). While such changes have undoubtedly impacted ecosystem structure and function, the evidence linking them to woody encroachment is mixed, and the underlying processes are not fully understood. To clarify the role of demographic processes in changing woody plant abundance, we conducted a meta-analysis of...

Korean oak wilt disease associated with Dryadomyces quercus-mongolicae recently emerged as a major tree disease in South Korea. A comprehensive transcriptome analysis is presented for D. quercus-mongolicae grown in vitro on three different culture media, identifying nearly 7,000 expressed transcripts. Most transcripts are associated with proteins essential for fungal survival and growth. The 40S ribosomal protein S25, ceramide very long chain fatty acid hydroxylase, Epl1 protein, and ADP/ATP translocase are particularly important due to their critical roles in the metabolism and environment...

Fuels treatments intended to reduce fuel loads and improve forest health on public lands offer one way to reduce wildfire hazards in the wildland-urban interface (WUI), where the natural and built environments meet. However, for fuels treatment implementation to be successful, it must comply with regulatory and scientific standards and be supported by local communities, as lack of acceptance can lead to alterations, delays, or abandonment. To foster support, public land managers can engage directly with residents in communities near treatment areas through various communication channels or...

Myrtle rust caused by Austropuccinia psidii is one of the most important diseases affecting eucalypts (Eucalyptus spp. and Corymbia spp.) in Brazil. Asexual spores of the myrtle pathogen, urediniospores, give rise to infection of young tissues (e.g., leaf, stem, flower and fruit) of the myrtaceous hosts. Symptoms of myrtle rust disease are necrosis and leaf deformation, and death of the apical shoots, whereas the primary diagnostic signs of myrtle rust disease are yellow urediniospores, which are formed by the myrtle rust pathogen on the infected organs. Occasionally, teliospores are...

Survival of perennial grasses between wet seasons depends on the maintenance of belowground buds and root systems. Belowground bud and root traits were evaluated in three perennial grasses (Pennisetum mezianum (Leeke), Digitaria macroblephara (Hack. ex Schinz) Paoli, and Themeda triandra (Forssk.) in semi-arid Kenyan rangelands during the short dry season. Bud number remained stablae while bud size declined for all three grass species during the study period. Non-structural carbohydrates in roots and percent root dry matter had increased in all three species by the end of the dry season....

-- The mechanistic links between fire-caused injuries and post-fire tree mortality are poorly understood. Current hypotheses differentiate effects of fire on tree carbon balance and hydraulic function, yet critical uncertainties remain about the relative importance of each and how they interact. -- We utilize two prescribed burns with Douglas-fir and ponderosa pine to examine: the relative evidence for fire-caused changes in hydraulic function and carbon dynamics, and how such impacts relate to fire injuries; which impacts most likely lead to post-fire mortality; and how these impacts vary...

1. Human activities have significantly altered terrestrial ecosystems, leading to biodiversity loss and habitat fragmentation. Traditional methods for measuring human impacts often lack the precision required for localized assessments, fail to capture temporal dynamics or are scale-limited. Human mobility data (HMD) from GPS-enabled smartphone applications offers a valuable approach to understanding human movement patterns, overcoming many of these limitations. 2. We present case studies demonstrating the use of HMD in assessing human activity within ecologically sensitive habitats (e.g....

Fire-caused tree mortality has major impacts on forest ecosystems. One primary cause of post-fire tree mortality in non-resprouting species is crown scorch, the percentage of foliage in a crown that is killed by heat. Despite its importance, the heat required to kill foliage is not well-understood. We used the “lag” model to describe time- and temperature-dependent leaf cell necrosis as a method of predicting leaf scorch. The lag model includes two rate parameters that describe 1) the process of cells accumulating non-lethal damage, and 2) damage becoming lethal to the cell. To parameterize...