Linking woodland key habitat inventory and forest inventory data to prioritize districts needing conservation efforts

Woodland key habitat (WKH) inventories have been conducted in northern European countries, with the aim to create networks of minimally disturbed forest stands for protection. The goal of national forest inventory is to provide information relevant to forest management, such as on forest types, trees species composition, age structure and wood volume. The aim of this study was to link these two inventory databases to identify districts of Latvia most deficient in connectivity and habitat quality, in order to prioritize districts needing conservation effort. As an example, the area of deciduous forest with nemoral tree species (oak, ash, lime, maple and elm) and aspen was chosen. These fores…

Movement of Metals to New Growing Tissue in the MossHylocomium splendens(Hedw.) BSG

To obtainHylocomium splendens(Hedw.) BSG. that varied in metal (K, Mg, Ca and Zn) content, moss samples were collected from six sites around a zinc contaminated area of Latvia; metal contents were artificially lowered by branch excision. The first fully expanded annual segment (mature segments), together with the unexpanded segment (juvenile segment) were grown in the laboratory with watering from below. The contents of K, Mg, Ca and Zn in new growth were correlated with initial contents in the juvenile+mature segments. However, the concentrations of these metals in the new growth were generally not correlated with those in the pre-experimental segments. The excision of branches from the ma…

Changes in climatic signals of English oak tree-ring width and cross-section area of earlywood vessels in Latvia during the period 1900–2009

Abstract We investigated changes in response of wood formation in English oak (Quercus robur L.) to climatic factors since 1900. It was hypothesised that the effect of winter and spring temperatures has weakened, while summer precipitation has become limiting. Increment cores were taken from 40 sites across Latvia. Tree-ring width and cross-section area of earlywood vessels were measured and cross-dated. Regional chronologies were built by pooling time series of trees within two regions of Latvia (western and eastern region), which differed in continentality. Climatic signals differed between the proxies (tree-ring width and earlywood vessel cross-section area) and between regions. Mean cro…

Environmental assessment in Latvia: Overview of past research and future perspectives

Plant functional trait response to environmental drivers across European temperate forest understorey communities

Functional traits respond to environmental drivers, hence evaluating trait-environment relationships across spatial environmental gradients can help to understand how multiple drivers influence plant communities. Global-change drivers such as changes in atmospheric nitrogen deposition occur worldwide, but affect community trait distributions at the local scale, where resources (e.g. light availability) and conditions (e.g. soil pH) also influence plant communities. We investigate how multiple environmental drivers affect community trait responses related to resource acquisition (plant height, specific leaf area (SLA), woodiness, and mycorrhizal status) and regeneration (seed mass, lateral s…

Pointer years in tree-ring width and earlywood-vessel area time series of Quercus robur—Relation with climate factors near its northern distribution limit

Abstract For a long time, radial growth of pedunculate oak (Quercus robur) in relation to environmental factors has been studied in Central Europe. However, there is insufficient information on oak growth in the Baltic region. Climate–growth interactions have been mostly investigated by correlation/response analysis between ring width and climatic factors. Other wood anatomical proxies, and also pointer year analysis, which focuses on weather extremes, can be sources of additional information. Wood samples were taken from 40 sites across Latvia. Tree-ring width (TRW) and mean area of earlywood vessels (EVA) were measured. To assess differences in wood formation among sites, a PCA was perfor…