Spruce Beetle outbreaks guide American Three‐toed Woodpecker Picoides dorsalis occupancy patterns in subalpine forests

American Three‐toed Woodpeckers Picoides dorsalis are considered a sensitive species by the United States Bureau of Land Management and are on the United States Fish and Wildlife Service's Watch List. In Idaho, Oregon and Washington, they are of conservation concern due to low abundance and an apparent reliance on disturbed, old‐growth forests. This species is strongly associated with Spruce Beetle Dendroctonous rufipennis epidemics, yet their occupancy relation with epidemic conditions have not been described. We studied Three‐toed Woodpecker occupancy patterns in spruce–fir forests experiencing varying degrees of beetle infestation between 2013 and 2016. Accounting for detection probability, we found a strong positive relationship between occupancy and the density of currently infested trees. Estimated occupancy was 0.57 (Bayesian credible interval 0.49, 0.64) for 75‐m‐radius survey points with zero infested spruce trees vs. 0.99 (Bayesian credible interval 0.99, 1) for points with 235 recently infested stems per ha. In contrast, we found no relationships with density of trees infested at least 3 years prior to sampling, density of older snags (i.e. > 10 years dead) or quadratic mean diameter of healthy or recently infested trees. These results provide evidence of the importance of active Spruce Beetle infestation for Three‐toed Woodpecker habitat. Conserving Spruce Beetle‐infested trees for at least 3 years following the onset of a beetle epidemic would benefit Three‐toed Woodpecker populations and other species that depend on woodpecker‐excavated cavities. We suggest managers consider these results when planning logging activities aimed at Spruce Beetle mitigation.     

Effects of forest dieback on wood decay,saproxylic communities,and spruce seedling regeneration on coarse woody debris

Picea is one of the most dominant conifer genera in the Northern Hemisphere and includes species which require coarse woody debris (CWD) as a seedbed for regeneration. To understand the future of forest distribution under global climate change, it is important to investigate regeneration mechanisms in Picea forests on the borders of its distribution. In the present study, we evaluated the biotic factors affecting the establishment of Picea jezoensis var. hondoensis seedlings on CWD in one of its southernmost populations in central Japan, where there is dieback of Picea forest. Amplicon sequencing of the fungal ITS1 region of rDNA obtained from wood samples showed that forest dieback increased the frequency of brown rot fungi in CWD. The frequency of brown-rotted wood, in which wood holocellulose is decayed, increased with dieback intensity. The domination of brown-rotted wood in dieback forests was negatively associated with bryophyte cover which was positively associated with Picea seedling density. Forest dieback itself also had other strong negative effects on bryophytes. Thus, linkages between dead wood and spruce seedlings via bryophytes had collapsed after the dieback event, which may partly be a reason that the spruce forest shifted to and is staying as open grassland.     

The effect of femel- and small scale clear-cutting on ground dwelling spider communities in a Norway spruce forest in Southern Germany

The early effects of femel-cutting (removing 20% of the trees) and small scale clear-cutting on ground-living spiders in a Norway spruce (Picea abies (L.) Karst.) forest in Southern Germany were investigated. The study was carried out as BACIP (before and after, control-impact, many paired samplings) study: Spiders were sampled during the pre-treatment year, the year of cutting, and the year after cutting. In total 7101 individuals were sampled, of which 4530 individuals were identified, 4468 were adult and 2633 individuals were juvenile. We identified 107 species, but a single species, Coelotes terrestris, dominated the control (spruce stand) comprising up to 49% of the total identified individuals. Clear-cutting changed the species composition in the traps, while the first step in femel-cutting preserved it. The number of individuals of the families Linyphiidae, Amaurobiidae, Agelenidae and Clubionidae decreased drastically within the 2 years after the clear-cutting, while the Lycosidae became numerically dominant in the clear-cut stands. The number of individuals with the following characterisation decreased significantly after clear-cutting: Small (<3.0 mm) and large spiders (>10.5 mm), web builders, ‘forest habitat species’, species favouring hygrophilic to medium moisture conditions, and preferences to live below ground or in and on the moss layer. On the other hand, middle-sized spiders, free hunters, ‘open habitat species’, spiders favouring dry conditions or that are euryoecious, preferring patterns covered by grasses or uncovered patches, increased in number. Clear-cut habitats with dense spruce regeneration showed a delayed and less pronounced response. With femel-cutting, species composition of ground-living spider communities may be preserved during the first step of regeneration of mature forest stands.     

Climate signal strength in tree-ring width of spruce growing in the Solovetsky Islands (Russia)

In this study we used 14 spruce tree-ring width local chronologies from sites that are located in different landscape conditions. The climatic response function for the entire period (116 years) shows that all local chronologies without exception have a positive relationship with June temperature (from 0.196 to 0.408) despite quite different local environmental conditions. This finding allowed us to combine all tree-ring width local chronologies into a composite spruce chronology covering the period of 1676–2016 CE with EPS exceeding the 0.85 threshold. The composite chronology was scaled against June air temperatures (CRU TS 4.01) in order to reconstruct it. Monthly air temperature records from the Arkhangelsk weather station were used as an additional source to validate tree-ring based June temperature reconstruction. It is quite remarkable that our reconstruction matches the Archangelsk records not only in the 20th-early 21st centuries but also in the 19th century, confirming the reliability of the reconstruction over more than two centuries. We also used daily records from the nearest Kem’-Port station to identify a more precise target-window. Current research shows that the spruce response to daily temperature is not limited by June, but also extends up to almost half of July. The warmest reconstructed year occurred in 1856 as confirmed by the data published in the local chronicle. The cooling recorded in the historical evidences (describing extremely severe ice conditions in the Arctic seas during the Great Northern Expedition (1733–1743)) was not corroborated by our reconstruction. In the study, we discuss the reasons of the discrepancies found between Solovki June temperature reconstructions and other data such as different seasonality of the compared records, real local climate warming in Solovki, the applied standardization technique, and low of chronologies’ replication. The most reliable part of the reconstruction part lasting from the early 19th to the early 21st centuries is also discussed in terms of its properties like wavelength analyses, and the assessment of influence of volcanic eruptions.     

Partial purification from hepatoma cells of an intracellular substance which mediates the effects of insulin on pyruvate dehydrogenase and low Km cyclic AMP phosphodiesterase

A substance capable of stimulating the activities of pyruvate dehydrogenase and low K_m cyclic AMP phosphodiesterase was prepared from H4-II-EC3′ hepatoma cells by acid extraction and partially purified by molecular exclusion chromatography. The material thus prepared by gel chromatography was found to stimulate the activities of these enzymes in a concentration-dependent manner. The amount or activity of the pyruvate dehydrogenase stimulating factor was increased in cells which had been treated with physiological concentrations of insulin (0.2 mU/ml). Increasing the concentration of insulin increased the amount or activity of the factor generated. High concentrations of insulin did not cause a reversal of the effects of insulin. The stimulation of pyruvate dehydrogenase activity by the factor was eliminated when sodium fluoride (75 mm) was present in the enzyme assay, implying that activation was mediated by the pyruvate dehydrogenase phosphatase. The enzyme-stimulating factor isolated from hepatoma cells shares a number of important characteristics with the putative second messenger of insulin prepared from other cell types: (1) it is heat and acid stable, (2) it has a similar apparent molecular weight, (3) it is generated in an insulin-dependent manner, (4) it stimulates the activity of pyruvate dehydrogenase by a fluoride-sensitive mechanism, and (5) it elutes from the anion-exchange resin AG 1-X8 at an ionic strength of 0.4 m. These findings suggest that the stimulator of pyruvate dehydrogenase and of low K_m cyclic AMP phosphodiesterase isolated from hepatoma cells has chemical properties identical with those of the putative second messenger of insulin action isolated from a number of other insulin-sensitive tissues.     

Dendroclimatic signals in the pine and spruce chronologies in the Solovetsky Archipelago

Searching for a robust tree-ring parameter useful for paleoclimatic purposes is one of the most demanding topics in the modern paleoscience. Since Blue Intensity has already expressed itself in different geographical locations all over the world as a possible replacement for maximum density, close attention is paid to investigate features of the inferred signal. The Solovki Islands is a unique location in Northern Russia where two important factors that make this territory attractive for developing a long tree-ring chronology have been met: modern long-living trees and building activities using old trees that were started by monks in the middle of the 16th century. The main goal of the research is to develop pine and spruce chronologies based on tree-ring width (TRW) and delta Blue Intensity (dBI) and to assess the ability of these parameters to be used as climate predictors. As a result, 14 conifer chronologies from 7 sites (4 for pine and 3 for spruce) were developed. The composite pine and spruce chronologies span a period of 474 and 378 years each. Cross-correlation of dBI-based chronologies of both conifers is high (r = up to 0.71 while for TRW-based chronologies it is lower on average (−0.18 to 0.63). Intra-species correlation of TRW chronologies in some cases achieved even negative values (r = −0.18. Discrepancies found between TRW chronologies of pine and spruce could be explained by differences in climatic signals. Response function analysis with monthly temperatures revealed that growth of pine depends on the previous August, while spruce has a temporally stable and strong relation to June temperatures. Compared to TRW, dBI-based chronologies have a high correlation with summer temperatures (r = 0.64 and 0.66 for spruce and pine, respectively). Presented research points out the importance of the response function analysis suggesting that depending on goals of the study several tree-ring parameters could be used, e.g., tree-ring width of spruce responses to June temperatures, while dBI to the whole summer.     

Isolation of myelin basic protein-reactive T-cell lines from normal human blood

T-Cell lines which responded by proliferation to the autoantigen, myelin basic protein (MBP), were isolated from the blood of six of nine normal humans. These T-cell lines could be maintained in in vitro culture for up to 2 months through the use of Interleukin 2 and repeated MBP stimulation. Optimal antigen-induced proliferation required both antigen and antigen-presenting cells found in the adherent cell population of autologous peripheral blood mononuclear cells (PBM). The T-cell lines were predominantly of the helper phenotype (OKT3+, OKT4+, OKT8-) and responded to both human and guinea pig myelin basic protein.