Treesearch

Background. Climate change is expected to increase fire activity across the circumboreal zone, including central Siberia. However, few studies have quantitatively assessed potential changes in fire regime characteristics, or considered possible spatial variation in the magnitude of change. Moreover, while simulations indicate that changes in climate are likely to drive major shifts in Siberian vegetation, knowledge of future forest dynamics under the joint influence of changes in climate and fire regimes remains largely theoretical. We used the forest landscape model, LANDIS-II, with...

Turfgrass lawns in residential yards can have significant water requirements. However, it is difficult to estimate how much water is consumed by lawns in households that vary in landscape type, management, and climate both within and across different cities. We visited 79 residential households in the United States and measured water use, or evapotranspiration (ET), of turfgrass lawns in six cities with different climates and yard management practices. Lawns used 0.6–1.3 mm of water per day in humid cities, and 2.2–3.6 mm per day in hot and dry cities. Lawn water use was more strongly...

Urban trees are an important part of biodiversity in urban areas, from cities to periurban suburbs and exurbs. Trees are often the base or underlying ecological support for other biota since they provide habitat, food, and influence other environmental conditions like temperature and moisture. Urban trees provide diverse ecosystem services for people, too, such as providing shade and cooler temperatures, aesthetic value, increases in senseof- place and social cohesion, reductions in crime, and improvements to physiological and psychological health and well-being.

Since the emergence of White-nose Syndrome, a fungal disease in bats, caused by Pseudogymnoascus destructans, hibernating populations of little brown bats (Myotis lucifugus) have declined by 70–90% within P. destructans positive hibernacula. To reduce the impact of White-nose Syndrome to North American little brown bat populations we evaluated if exposure to volatile organic compounds produced by induced cells from Rhodococcus rhodochrous strain DAP96253 could improve the overwinter survival of bats infected by P. destructans. Two simultaneous field treatment trials were conducted at...

Invasive plants, which cause substantial economic and ecological impacts, acquire both pathogens and beneficial microbes in their introduced ranges. Communities of fungal endophytes are known to mediate impacts of pathogens on plant fitness but few studies have examined the temporal dynamics of fungal communities on invasive plants. The annual grass Microstegium vimineum, an invader of forests and riparian areas throughout the eastern United States, experiences annual epidemics of disease caused by Bipolaris pathogens. Our objective was to characterize the dynamics of foliar fungal...

Invasive plants can significantly impact the diversity of understory ground flora and forest regeneration in eastern North America. However, managing invasive plants has resulted in positive, negative, or neutral effects on key ecosystem components depending on treatment type, duration, and intensity. Management may also result in short-term control, but legacy effects from prior land use or secondary invasions may hamper desired long-term outcomes. We conducted a systematic review of the invasive plant management literature for eastern North American forests to examine treatment outcomes...

Introduction: Timber harvests influence coarse woody debris (CWD) dynamics both initially and long-term—contributing a significant amount of CWD as slash immediately after harvest, but also removing some or all of the mature trees necessary to produce CWD over time. Whereas shelterwood and other similar timber harvest systems retain varying amounts of the overstory, preserving CWD production after harvest, commercial clearcutting essentially eliminates sources of fresh CWD until regenerating trees are large enough to contribute CWD through fallen limbs or trunks, often decades after...

Questions: Fire regime alterations are pushing open ecosystems worldwide past tipping points where alternative steady states characterized by woody dominance prevail. This reduces the frequency and intensity of surface fires, further limiting their effectiveness for controlling cover of woody plants. In addition, grazing pressure (exotic or native grazers) can reinforce woody encroachment by potentially reducing fine-fuel loads. We investigated the effects of different fire energies on the herbaceous plant community, together with mammalian wildlife herbivory (exotic and native combined)...

Aim: Non-native species are part of almost every biological community worldwide, yet numbers of species establishments have an uneven global distribution. Asymmetrical exchanges of species between regions are likely influenced by a range of mechanisms, including propagule pressure, native species pools, environmental conditions and biosecurity. While the importance of different mechanisms is likely to vary among invasion stages, those occurring prior to establishment (transport and introduction) are difficult to account for. We used records of unintentional insect introductions to test (1)...

Leaching of excess nitrogen (N) to groundwater in fertilized landscapes can overwhelm natural biogeochemical processes and cause long-term eutrophication of aquatic systems. We investigated N fate and transport from an intensively managed short-rotation woody crop (Pinus taeda) plantation through the riparian zone of an intermittent, low-gradient blackwater stream. Fertilization of the P. taeda plantation on the uplands resulted in contamination of groundwater with nitrate concentrations between 0.9 and 1.9 mg N L− 1. No corresponding increase in nitrate was observed in stream water or...