Treesearch

Persicaria perfoliata (Mile-a-Minute Weed), an invasive vine, forms monocultural patches of various sizes within infested landscapes among patches also containing other plants. We compared the species composition of P. perfoliata-dominated patches and adjacent nondominated patches in 2 topographically homogeneous sites using 20 paired plots, nonmetric multidimensional scaling, multi-response permutation procedure, and indicator species analyses. Richness and diversity were lower in the P. perfoliata-dominated patches but both patch types had uncommon native plants present. The patch types...

We evaluated the productivity and profitability of four highly productive poplars including Populus deltoides× P. deltoides (DD '140' and '356'), P. deltoides× P. maximowiczii (DM '230'), and P. trichocarpa× P. deltoides (TD '185') under two densities (2500 and 5000 trees ha-1), and three fertilization treatments (0, 113, 225 kg nitrogen ha-1) at three sandy coastal sites varying in soil quality. Green stem biomass (GSB) was estimated from the sixth-year stem diameter. Leaf-rust (Melampsora castagne) and beetle damage (by Chrysomela scripta Fabricius), the leaf area index (LAI) and foliar...

The present special issue highlights the chances and addresses the main challenges for short rotation coppices (SRC) with poplars (Populus spp.) as agricultural crops for the sustainable bio-economy. The current public perception of planting more trees on Earth as a climate mitigation action is accompanied by controversial discussions about sustainability and biodiversity of tree plantations. In contrast to many industrial plantations in the tropics, agricultural tree cropping with site-adapted tree species in the temperate zones of the world follows an agroforestry concept towards more...

Hybrid poplars (Populus sp.) are increasingly implemented in agroforestry systems across the U.S., mainly for their biomass production, carbon allocation, and ecosystem services. While agroforestry systems are usually established on marginal land, soil amendments, such as paper mill fibercake residuals, can provide necessary nutrients such as nitrogen (N) to increase poplar yield. To assess the effects of such amendments on poplar early growth and establishment, three clones (Populus deltoides Bartr. ex Marsh × P. maximowiczii A. Henry 'DM114'; P. deltoides× P. nigra L. 'DN170'; P. nigra×...

Tree size-density dynamics can inform key trends in forest productivity along with opportunities to increase ecosystem resiliency. Here, we employ a novel approach to estimate the relative density (RD, range 0-1) of any given forest based on its current size-density relationship compared to a hypothetical maximum using the coterminous US national forest inventory between 1999 and 2020. The analysis suggests a static forest land area in the US with less tree abundance but greatly increased timber volume and tree biomass. Coupled with these resource trends, an increase in RD was identified...

Native pollinator populations across the United States are increasingly threatened by a multitude of ecological stressors. Although the drivers behind pollinator population declines are varied, habitat loss/degradation remains one of the most important threats. Forested landscapes, where the impacts of habitat loss/degradation are minimized, are known to support robust pollinator populations in eastern North America. Within heavily forested landscapes, timber management is already implemented as a means for improving forest health and enhancing wildlife habitat, however, little is known...

The northern Lake Huron shoreline in Michigan's Upper Peninsula has a largely east west orientation, extending from St. Ignace eastward to DeTour Village and then to neighboring Drummond Island (Fig. 1). Given this orientation, this shoreline intercepts large numbers of spring migrating birds after they fly across Lake Huron. These birds need to rest and refuel. For many of the insectivorous passerines or perching birds such as warblers (Fig. 2), vireos, and thrushes, they often arrive before the hardwood trees have fully leafed out and thus there are relatively few terrestrial insects...

We investigated changes in soil chemistry and foliar metabolism of Himalayan cedar [Cedrus deodara (Roxb. Ex Lamb.) G.Don] and Himalayan spruce [Picea smithiana (Wall.) Boiss] trees along a steep elevational gradient in the lower Himalayan Mountains at Kufri, Himachal Pradesh (HP), India. The foliar and soil samples were collected from four locations along a 300 m elevational gradient at ridge, high-, mid-, and low-elevation sites within the forested ShimlaWater CatchmentWildlife Sanctuary that provides water for the city of Shimla, HP,. Observations at the time of sampling revealed that...

Downed woody material (DWM) is a unique part of the forest carbon cycle serving as a pool between living biomass and subsequent atmospheric emission or transference to other forest pools. Thus, DWM is an individually defined pool in national greenhouse gas inventories. The diversity of DWMcarbon drivers (e.g., decay, tree mortality, orwildfire) and associated high spatial variability make this a difficult-to-predict component of forest ecosystems. Using the now fully established nationwide inventory of DWM across the United States (US), we developed models, which substantially improved...

A demographic Allee effect refers to increasing per capita population growth with increasing abundance. It arises from component Allee effects, which exist when some component of individual fitness has a positive relationship with density. Newly arrived populations tend to be small, and their establishment success is influenced by various factors, including demographic Allee effects. Identifying mechanisms driving the Allee effect is of relevance for understanding establishment failure, developing strategies for improving biological control and conservation, and for managing biological...