Treesearch

Farmers, particularly small farmers, are on the frontlines of climate change. In Oregon’s Southern Willamette Valley, a needs assessment was conducted of small farmers in 2017, where questions related to climate change risks, attitudes toward adaptation and climate beliefs were assessed. Out of all the respondents (n = 123), the majority (70%) believe that climate change is occurring, and is caused mostly by human activities. The majority (58%) also strongly agree with the statement that they will have to change practices to cope with increasing climate variability in order to ensure the...

There has been an increasing interest in the economic health cost from smoke exposure from wildfires in the past 20 years, particularly in the north-western USA that is reflected in an emergent literature. In this review, we provide an overview and discussion of studies since 2006 on the health impacts of wildfire smoke and of approaches for the estimation of the associated economic cost. We focus on the choice of key variables such as cost estimators for determining the economic impact of mortality and morbidity effects. In addition, we provide an in-depth discussion and guidance on the...

In this study, for five sites around the world, we look at the effects of different model types and variable selection approaches on forest yield modelling performances in an area-based approach (ABA). We compared ordinary least squares regression (OLS), k-nearest neighbours (kNN) and random forest (RF). Our objective was to test if there are systematic differences in accuracy between OLS, kNN and RF in ABA predictions of growing stock volume. The analyses are based on a 5-fold cross-validation at five study sites: an eucalyptus plantation, a temperate forest and three different boreal...

The flame length of a plume in incompressible cross-flow is analyzed and the results are compared with those obtained in a chemically reacting water tunnel experiment. It is argued that the axial vortex pair in the flow arises from the plume momentum normal to the free stream, the momentum flux being equivalent to the impulse from the buoyant force.

Knowledge of the recruitment of dominant forest species is a key aspect for forest conservation and the ecosystem services they provide. In this paper, we address how the simultaneous action of climate change and the intensity of land use in the past influence the recruitment of a forest species that depends on the provision of nurse plants to recruit. We compared the number of saplings (up to 15 years old) and juveniles (16 to 50 years old) of Quercus ilex in 17, 5.3 ha plots in the Iberian System (eastern Spain). We used a gradient of past deforestation intensity crossed with two levels...

Anthropogenic disturbances in tropical forests cause shortand long-term alterations in forest structure, species composition, and successional processes. However, improved understanding of the impacts of disturbance on forest functioning is needed to support forest management and conservation. In this study, we investigated the phenological responses of two sites in the Brazilian Amazon to forest degradation (selective logging and forest fires). We used MODIS-derived time-series to assess pre- and post-disturbance trajectories of two vegetation indices: Normalized Burn Ratio (NBR) and...

Mortality of trees is an important ecological process altering forest structure and function as well as influencing forest management decisions. Recent observations suggest that the overall rate of tree mortality is increasing at local to global scales. While more data on mortality is needed to document these changes, key concepts are also needed to guide the collection, interpretation, and use of this information. Mortality can be considered as a general process that includes all forms of tree-related death ranging from parts of trees to large-scale disturbances. Viewing mortality as a...

The U.S. Fish and Wildlife Service (USFWS) developed an invasive species risk assessment procedure, presented in Marcot et al. (2019), consisting of an existing rapid assessment process for plants and animals (Ecological Risk Screening Summary; ERSS) and a new probability-based Bayesian network model (Freshwater Fish Injurious Species Risk Assessment Model; FISRAM), that may be used to help prioritize invasive freshwater fish species for Federal injurious wildlife listing evaluation by USFWS under the Lacey Act. Hill et al. (2020) provided a rebuttal letter of Marcot et al. (2019) but did...

Mule deer (Odocoileus hemionus) are widely hunted throughout western North America and are experiencing population declines across much of their range. Consequently, understanding the direct and indirect effects of hunting is important for management of mule deer populations. Managers can influence deer mortality rates through changes in hunting season length or authorized tag numbers. Little is known, however, about how hunting can affect site fidelity patterns and subsequent habitat use and movement patterns of mule deer. Understanding these patterns is especially important for adult...

Disturbance refugia – locations that experience less severe or frequent disturbances than the surrounding landscape – provide a framework to highlight not only where and why these biological legacies persist as adjacent areas change but also the value of those legacies in sustaining biodiversity. Recent studies of disturbance refugia in forest ecosystems have focused primarily on fire, with a growing recognition of important applications to land management. Given the wide range of disturbance processes in forests, developing a broader understanding of disturbance refugia is important for...