Treesearch

Aquatic invasive species (AIS) threaten ecosystem health, serving as a major challenge for conservation efforts worldwide. Invasive species easily move across jurisdictional boundaries that may each have diverse management approaches, leading to management mosaics in which each manager’s actions impact those of neighboring jurisdictions. Here, we investigate the potential impact of collaborations between counties in Minnesota in managing four aquatic invasive species (Eurasian watermilfoil, spiny waterflea, starry stonewort, and zebra mussels), with a focus on evaluating the efficiency of...

The 285 million ha of forestland in the U.S. (Butler et al., 2021) exist within a complex socio-political-economic environment that has fundamentally shaped the current state of the forests and has major implications for the future of the forests. A key element of this social context is ownership; the owners of the land – working within biophysical, social, political, and economic constraints – make decisions about land disposition. They decide whether the land remains forested, how it will be managed, and who will have access to the land and many of the benefits it provides.

Preserving the abundance and stocking of oaks (Quercus spp.) has become increasingly challenging in temperate hardwood forests of the eastern US in recent decades due to a remarkable shift in dominance to mesophytic species (e.g., red maple Acer rubrum). Studies have shown that efforts to sustain oaks while restraining maples yield limited success. Given that a significant portion of forestlands in the eastern U.S. are privately owned, it is critical to assess whether current forest management on cross-ownership forests can achieve those objectives. However, such assessments are rare. In...

The geographical exchange of non-native species can be highly asymmetrical, with some world regions donating or receiving more species than others. Several hypotheses have been proposed to explain such asymmetries, including differences in propagule pressure, source species (invader) pools, environmental features in recipient regions, or biological traits of invaders. We quantified spatiotemporal patterns in the exchange of non-native insects between Europe, North America, and Australasia, and then tested possible explanations for these patterns based on regional trade (import values) and...

Throughout eastern North America, chronic white-tailed deer overbrowsing and widespread exotic plant invasions degrade native plant diversity and abundance. However, because deer densities are high across entire regions, it is challenging to find large areas where deer have been at low density for long periods. We predicted native plant diversity and abundance would be significantly higher during gap-phase regeneration where deer have been maintained at low densities (~ 7 deer/km2) compared to where deer have been chronically overabundant. Simultaneously, we predicted that exotic plant...

1. Defoliators cause extensive damage in boreal and temperate forests of the world. Considerable effort has been invested to understand their individual population dynamics, and despite ample theorising, there is little empirical evidence on factors causing spatial synchrony of pest eruptions at landscape scales. 2. We report on the landscape-level effect of forest configuration and composition on the intensity of outbreaks of spruce budworm and forest tent caterpillar in a mixedwood boreal forest in northern Minnesota (USA) and adjacent Ontario (Canada), and how this is related to the...

Anticipating and preparing for the future are among the challenges land managers face when making decisions about how to balance the public's desire for outdoor recreation with ecological concerns. A recent General Technical Report by Lynne Westphal, emerit research social scientist with the U.S. Department of Agriculture Forest Service Northern Research Station, aims to assist managers by analyzing potential changes in recreation on public lands 30 years into the future.

The integration of native prairie vegetative strips into row crop agriculture is a promising conservation strategy that has gained momentum in adoption rates throughout the US Midwest. Previous studies have shown that prairie strip establishment can lead to several positive soil and water quality outcomes, such as reductions in surface runoff and nutrient and sediment exports. However, the impacts of prairie strips on soil infiltration are not well known. In this study, the Cornell Sprinkle Infiltrometer system was used to measure differences in field-saturated infiltration rate between...

Planting low-pollen trees could reduce aeroallergen exposure in cities, but the effects of historical tree planting on contemporary airborne pollen exposure remains largely unexplored. Whether tree selection decisions can effectively reduce airborne pollen will depend in part on which taxa are the most important sources of allergenic pollen and the extent to which they are intentionally planted vs. unplanted (i.e., recruiting naturally). Here, we use airborne pollen measurements to examine which taxa are of allergenic importance in New York City (NYC), and then combine two tree surveys...

This summary report provides an overview of findings from the fourth full annualized inventory of Indiana forests based on data collected from 2012 to 2018. Indiana has nearly 4.9 million acres of forest land with an average of 442 trees (at least 1.0-inch in diameter) per acre. Hardwoods are the dominant tree species in Indiana. Forest land is dominated by the oak/hickory forest-type group, which occupies 72 percent of the total forest land area (3.5 million acres). Live tree volume averages 2,240 cubic feet per acre. Growing-stock net growth exceeds removals resulting in a growth-to-remov...