Treesearch

Tomorrow’s forests face extreme pressures from contemporary climate change, invasive pests, and anthropogenic demands for other land uses. These pressures, collectively, demand land managers to reassess current and potential forest management practices. We discuss three considerations, functional restoration, assisted migration, and bioengineering, which are currently being debated in the literature and have the potential to be applied independently or concurrently across a variety of scales. The emphasis of functional restoration is to reestablish or maintain functions provided by the...

Strategic fire and fuel management planning benefits from detailed understanding of how wildfire occurrences are distributed spatially under current climate, and from predictive models of future wildfire occurrence given climate change scenarios. In this study, we fitted historical wildfire occurrence data from 1986 to 2009 to a suite of spatial point process (SPP) models with a model averaging approach. We then predicted human- and lightning-caused wildfire occurrence over the 2010-2100 period in the Lake Tahoe Basin, a forested watershed in the western US with an extensive wildland-urban...

In two hemiboreal mixed spruce-hardwood forests in north-east Estonia, we studied (1) which factors affect tree regeneration survival and development during the first post-storm decade and (2) how these effects change in time. Regeneration height and mortality of the tree species black alder (Alnus glutinosa (L.) J. Gaertn.), birch (Betula pendula Roth., Betula pubescens Ehrh.), Norway spruce (Picea abies (L.) Karst.) and European rowan (Sorbus aucuparia L.) were analysed in moderately and heavily damaged stands, in two types of windstorm-created microsites, i.e. root-plate pits and mounds...

Global changes, including climate change, are rapidly creating new environmental conditions and stressors for forests around the world. Climate change may have modest direct effects, at least initially, but indirect effects and interactions with disturbances can produce important changes in forest composition and landscape pattern (Dale et al. 2001; Gustafson et al. 2010), with consequences for ecological function and ecosystem services. Global Circulation Models generate varied predictions of future climate in any given part of the globe, and precipitation projections are usually much...

Background: Histone modifications play an integral role in plant development, but have been poorly studied inwoody plants. Investigating chromatin organization in wood-forming tissue and its role in regulating gene expression allows us to understand the mechanisms underlying cellular differentiation during xylogenesis (wood formation) andidentify novel functional regions in plant genomes. However, woody tissue poses unique challenges for using high-throughput chromatin immunoprecipitation (ChIP) techniques for studying genome-wide histone modifications in vivo. We investigated the role of...

Since Darwin's observation that secondary woodiness is common on islands, the evolution of woody plants from herbaceous ancestors has been documented in numerous angiosperm groups. However, the evolutionary processes that give rise to this phenomenon are poorly understood. To begin addressing this we have used a range of approaches to study the anatomical and genetic changes associated with the evolution and development of secondary woodiness in a tractable group. Begonia is a large, mainly herbaceous, pantropical genus that shows multiple shifts towards secondarily woody species inhabiting...

Northern peatlands represent a long-term net sink for atmospheric CO2, but these ecosystems can shift from net carbon (C) sinks to sources based on changing climate and environmental conditions. In particular, changes in water availability associated with climate control peatland vegetation and carbon uptake processes. We examined the influence of changing hydrology on plant species abundance and ecosystem primary production in an Alaskan fen by manipulating the water table in field treatments to mimic either sustained flooding (raised water table) or drought (lowered water table) condition...

Perennial ryegrass (Lolium perenne L.) is a widely cultivated cool-season grass species because of its high quality for forage and turf. Susceptibility to freezing damage limits its further use in temperate zones. The objective of this study was to identify candidate genes significantly associated with winter survival and spring regrowth in a global collection of 192 perennial ryegrass accessions. Significant differences in winter survival (WS), percentage of canopy green cover (CGC), chlorophyll index (Chl), and normalized difference vegetation index (NDVI) were found among accessions....

Uncertainties in ecophysiological responses to environment, such as the impact of atmospheric and soil moisture conditions on plant water regulation, limit our ability to estimate key inputs for ecosystem models. Advanced statistical frameworks provide coherent methodologies for relating observed data, such as stem sap flux density, to unobserved processes, such as canopy conductance and transpiration. To address this need, we developed a hierarchical Bayesian State-Space Canopy Conductance (StaCC) model linking canopy conductance and transpiration to tree sap flux density from a 4-year...

The aim of this study was to determine the effect of agricultural land afforestation on soil characteristics. Two sites in two regions of the Czech Republic were evaluated, at lower as well as higher submountain elevations: in the regions of the Orlicke hory Mts. and Kostelec nad Cernymi lesy, afforested, arable and pasture lands were compared for basic chemical and physical characteristics. It was determined: pH, CEC, exchangeable nutrients, SOC, bulk density, volume density, porosity (differentiated by pore size), water conductivity and soil aggregate stability. This study demonstrated...