Treesearch

Riparian zones are areas of transition between aquatic and terrestrial ecosystems, and their vegetation provides many important ecosystem services that are becoming of greater importance due to the changing climate. To understand riparian conditions along headwater tropical streams in terms of species composition and structure, we surveyed riparian tree communities and physical conditions in adjacent streams in the Luquillo Experimental Forest. We determined riparian substrate condition visually by estimating ground and vegetation attributes and measuring slope and elevation in a series of...

Many fire-prone forests are experiencing wildfires that burn outside the historical range of variation in extent and severity. These fires impact pollinators and the ecosystem services they provide, but how the effects of fire are mediated by burn severity in different habitats is not well understood. We used generalized linear mixed models in a Bayesian framework to model the abundance of pollinators as a function of burn severity, habitat, and floral resources in post-fire, mid-elevation, conifer forest, and meadow in the Sierra Nevada, California. Although most species-level effects...

The fisheries and aquatic sciences confront complex challenges in the overexploitation and degradation of aquatic-riparian ecosystems worldwide. Although the field comprises diverse natural resources available to diverse groups, changing the human face of its workforce so that it closely reflects everyone who depends on those resources has been slow. Brooke Penaluna, a research fisheries biologist from the USDA Forest Service Pacific Northwest Research Station, and her collaborators analyzed data on the status of diversity and inclusion and investigated strategies to enhance these values...

Defoliating insects inflict costly damage to forests, sometimes at landscape scales. Outbreaks of the native Douglasf-ir tussock moth (Orgyia pseudotsugata) occur every 5 to 10 years in the western United States and southern British Columbia. The larvae feed on the needles of Douglas-fir, grand fir, or white fir trees. If the defoliation becomes severe enough, they will kill the infested trees. Widespread outbreaks can cause extensive damage, including leaving the forest susceptible to infestation by other insect pests or wildfire. Outbreaks typically end when a naturally occurring,...

Anaxyrus microscaphus (The Arizona Toad) is an at-risk species that is endemic to the southwestern United States. Despite conservation concerns, little is known about the ecological drivers of its distribution and habitat use. We investigated the potential distribution of A. microscaphus at the range-wide scale and local scales (i.e., Zion National Park), using MaxEnt to model habitat suitability under current and future climate scenarios. Our models incorporated 12 environmental variables, including climatic, geomorphological, and remotely sensed data. The results showed good model...

The Earth is changing faster than at any time in recorded history. Globally, we are facing large-scale losses in biodiversity and associated ecosystem function, changes in disturbance regimes, and widespread human migration and cultural loss (e.g., IPCC 2021). In the United States, we face many related challenges, including intensifying wildfire and climatic events, species and habitat loss, increasing demand for environmental and social justice, and rapid social change such as urbanization.

The Pacific Northwest National Scenic Trail (PNT) traverses 1,200 miles from the Continental Divide to the Pacific Ocean. The portion of the trail in Northwest Montana and the Idaho Panhandle is at the nexus of a complex conflict situation involving outdoor recreation, wildlife conservation, and social-cultural values. This evolving conflict has gained national attention due to the diverse stakeholder interests and litigation against the US Forest Service, who administers the trail. The tension among the stakeholder groups and the various ecological and social-cultural dimensions at play...

Consider several of the most devastating fire disasters of the last century. In August 2023, the wildfire-initiated urban conflagration of Lahaina, Hawaii, damaged or destroyed more than 2,200 structures and killed 98 people. In December 2021, the Marshall Fire sparked conflagrations in Superior and Louisville, Colorado, destroying 1,084 structures and killing two. In September 2020, the Almeda Drive Fire in the communities of Talent and Phoenix, Oregon, destroyed 2,600 homes and killed three. In November 2018, the Camp Fire initiated ignitions in Paradise, California, destroyed 18,804...

Oak wilt is an aggressive vascular disease that typically kills infected trees within 3 to 8 months. It is particularly lethal for trees in the red oak group (section Lobatae). Oak wilt is caused by the fungus Bretziella fagacearum and transmitted over land by sap beetles (Coleoptera: Nitidulidea). Although the disease can be transmitted over land by sap beetles, the majority of oak wilt is spread by grafted roots from other nearby oaks with the infection.

Adelges (Cholodkovskya) viridanus (Cholodkovsky 1896) (Hemiptera: Adelgidae) is found throughout Eurasia where it is understood to be anholocyclic, feeding on species of larch (Larix), without host alternation. For the first time, we report this species in North America, outside of its native range, from specimens collected in an arboretum in Ohio, USA. Molecular phylogenetic analysis was inconclusive as to whether it was introduced from Europe or Asia. In addition, specimens collected from Picea jezoensis in Japan were confirmed for the first time as A. (C.) viridanus by matching DNA...