Keyword: North America

Examining post-fire vegetation recovery with Landsat time series analysis in three western North American forest types

Background: Few studies have examined post-fire vegetation recovery in temperate forest ecosystems with Landsat time series analysis. We analyzed time series of Normalized Burn Ratio (NBR) derived from LandTrendr spectral-temporal segmentation fitting to examine post-fire NBR recovery for several wildfires that occurred in three different coniferous forest types in western North America during the years 2000 to 2007.

Barriers to natural regeneration in temperate forests across the USA

For millennia, natural disturbance regimes, including anthropogenic fire and hunting practices, have led to forest regeneration patterns that created a diversity of forest lands across the USA. But dramatic changes in climates, invasive species, and human population, and land use have created novel disturbance regimes that are causing challenges to securing desired natural regeneration.

What drives at-risk species richness? Environmental factors are more influential than anthropogenic factors or biological traits

Species at risk of extinction are not uniformly distributed in space. Concentrations of threatened species may occur where threatening processes are intense, in refuges from those processes, or in areas of high species diversity. However, there have been few attempts to identify the processes that explain the distribution of at-risk species.

Twenty-five years after: Post-introduction association of Mecinus janthinus s.l. with invasive host toadflaxes Linaria vulgaris and Linaria dalmatica in North America

Linaria vulgaris, common or yellow toadflax, and Linaria dalmatica, Dalmatian toadflax (Plantaginaceae), are Eurasian perennial forbs invasive throughout temperate North America. These Linaria species have been the targets of classical biological control programmes in Canada and the USA since the 1960s.

The spatially varying influence of humans on fire probability in North America

Humans affect fire regimes by providing ignition sources in some cases, suppressing wildfires in others, and altering natural vegetation in ways that may either promote or limit fire.

Management of amphibians, reptiles, and small mammals in North America: Proceedings of the symposium

Historically the management of public lands from a multiple use perspective has led to a system that emphasizes those habitat components or faunal elements that primarily resulted in some sort of definable economic value. While this often benefitted other species that were not even considered in the original prescriptions, it also negatively impacted others. We no longer can afford to take this simplistic view of ecosystem management.

Satellite versus ground-based estimates of burned area: A comparison between MODIS based burned area and fire agency reports over North America in 2007

North American wildfire management teams routinely assess burned area on site during firefighting campaigns; meanwhile, satellite observations provide systematic and global burned-area data. Here we compare satellite and ground-based daily burned area for wildfire events for selected large fires across North America in 2007 on daily timescales.

Systematic temporal patterns in the relationship between housing development and forest bird biodiversity

As people encroach increasingly on natural areas, one question is how this affects avian biodiversity. The answer to this is partly scale-dependent. At broad scales, human populations and biodiversity concentrate in the same areas and are positively associated, but at local scales people and biodiversity are negatively associated with biodiversity.

New records and new host plants of powdery mildews (Erysiphales) from Idaho and Oregon (USA)

In the course of routine examinations of powdery mildews collected in Idaho and Oregon, USA, some of the identified species proved to be new to North America, in some cases on new host plants. Leveillula papilionacearum and L. picridis are first records from the USA. Astragalus filipes, Dalea ornata and D. searlsiae are new hosts for Leveillula papilionacearum. Enceliopsis, Heliomeris and Machaeranthera are new host genera for L. picridis.