Vegetation of the Forest River Biology Area in Relation to Environmental Gradients and Some Patterns and Processes of Nutrient Cycling

Vegetation-environment relationships were studied in 40 plots located on the slopes and the floodplain within the University of North Dakota Forest River Biology Area in northeastern North Dakota. Three of these plots, each dominated by a different major tree species, were selected for a detailed study (May to October, 1971) of nutrient input by litterfall, throughfall, and stemflow. Coverage values for 109 species of vascular plants and basal area, frequency, density, and mensuration data were determined for seven tree species. A total of 10 species of mosses and 15 of lichens are reported for the 40 plots. Dominant (based on importance value) overstory species are Quercus macrocarpa. Tilia americana, and Fraxinus pennsylvanica var. subintegerrima. Subordinate overstory species include Ulmus americana . Acer nequndo. Populus tremuloides . and Betula papyrifera. Tree-ring analysis indicates the present forest is less than 100 years old. Correlation analysis reveals that the basal area of trees and the number and coverage values of herbaceous species is higher on lower elevations and south exposures. Slope inclination, aspect, and elevation more strongly influence the distribution of the herbaceous element than they do trees and shrubs . Principal component analysis and Swan-Dix-Wehrhahn ordination were used to group objectively the 40 stands into five abstract community types . Principal component analysis produced similar but more distinguishable groupings than the Swan-Dix-Wehrhahn method. Environmental soil parameters measured for each horizon within the rooting zone include available water capacity; pH; specific conductivity; cation exchange capacity; percentage organic matter; water soluble calcium, magnesium, sodium, and potassium; replaceable calcium, magnesium, sodium, potassium, strontium, and manganese; available phosphorus; and EDTA-extractable copper, strontium, manganese, zinc, nickel, iron, lead, aluminum, and silicon. Topographic and soil parameters were used for stepwise- elimination multiple regressions to develop predictive equations for the distribution of plant species. Based on results from multiple regression analysis, gradients for potential solar beam irradiation, available water capacity, elevation, linear aspect, slope, and replaceable potassium were established. Using coverage values, ecological modalities of selected species are demonstrated along the quantified gradients. Generally, trees show a bimodal, shrubs and herbs a unimodal distribution. The distribution of community types along these gradients are also shown. Relationships of stands in several bivariate combinations show patterns of community type distribution resembling those obtained by stand ordination. Whereas pronounced vegetation differences occur between slopes and floodplain, the vegetation pattern on the slopes is continuous and overlapping. Interception of incident rainfall by the Tilia americana canopy (24.3%) was higher than by the Fraxinus pennsylvanica (12.3%) and Quercus macrocarpa (11.4%) canopies . Input of calcium, magnesium, potassium, and phosphorus in net rainfall (throughfall plus stemflow) was greatest under the Tilia canopy. and the input of sodium and sulfate was greatest under the Fraxinus canopy. Although seasonally variable, total litter production, ranging 2 from 247 to 265 g/m for the collecting period, was nearly the same in the three sites studied. Calcium levels were noticeably higher in woody litter, and magnesium, potassium, and phosphorus were higher in non- woody litter. The largest input of mineral elements occurred as follows: calcium, sodium, potassium, phosphorus, strontium, zinc, and copper in the site dominated by Tilia: manganese, iron, and aluminum in the Quercus site; and manganese in the Fraxinus site. The combined total input by net rainfall and litterfall of calcium, potassium, magnesium, phosphorus, and sodium in kilograms per hectare in the three sites ranged from 39.8 to 68.4 , 22.5 to 37.6 , 8.8 to 9.9 , 5.6 to 10.6, and 17.5 to 20.8, respectively. It is suggested that functional aspects on productivity and cycling in ecosystems be preceeded by well documented vegetation- environment relationships

Growth parameters of Sri Lankan children during infancy: A comparison with world health organization multicentre growth reference study

Objectives: growth monitoring (GM) is an important intervention ensuring wellbeing of children. If GM to be meaningful it is essential to have reference standards appropriate for that population. In Sri Lanka growth charts based on WHO multi centre growth reference study (MGRS) are used for GM. This study was carried out to ascertain the appropriateness of MGRS charts for GM in Sri Lankan children. Methods: out of a birth cohort of 2215 children, 250 from each sex were invited fora followed up. Children were examined at 2, 4, 6, 9 and 12 months, to measure weight and length. Statistical characteristics of weight and length for each sex were calculated and compared with MGR data. Results: out of babies invited to participate in the study 244 boys and 241 girls responded initially. Out of this 85% of boys and 86% of girls completed the follow up. Weight and length of both sexes deviated significantly at all ages from MGRS data. Conclusion: MGRS data seems to be inappropriate for monitoring growth of Sri Lankan childre

Identifying Personalized Metabolic Signatures in Breast Cancer.

Cancer cells are adept at reprogramming energy metabolism, and the precise manifestation of this metabolic reprogramming exhibits heterogeneity across individuals (and from cell to cell). In this study, we analyzed the metabolic differences between interpersonal heterogeneous cancer phenotypes. We used divergence analysis on gene expression data of 1156 breast normal and tumor samples from The Cancer Genome Atlas (TCGA) and integrated this information with a genome-scale reconstruction of human metabolism to generate personalized, context-specific metabolic networks. Using this approach, we classified the samples into four distinct groups based on their metabolic profiles. Enrichment analysis of the subsystems indicated that amino acid metabolism, fatty acid oxidation, citric acid cycle, androgen and estrogen metabolism, and reactive oxygen species (ROS) detoxification distinguished these four groups. Additionally, we developed a workflow to identify potential drugs that can selectively target genes associated with the reactions of interest. MG-132 (a proteasome inhibitor) and OSU-03012 (a celecoxib derivative) were the top-ranking drugs identified from our analysis and known to have anti-tumor activity. Our approach has the potential to provide mechanistic insights into cancer-specific metabolic dependencies, ultimately enabling the identification of potential drug targets for each patient independently, contributing to a rational personalized medicine approach

Mulch and groundcover effects on soil temperature and moisture, surface reflectance, grapevine water potential, and vineyard weed management

The objectives of this research were to identify alternatives to glyphosate for intra- row (under-trellis) vineyard floor management and to evaluate the potential for intra- row and inter-row (alleyway) groundcovers to reduce vegetative vigor of `Marquette\u27 grapevines (Vitis spp.) in a southeast Nebraska vineyard. The experiment was a randomized factorial design with five intra-row treatments (crushed glass mulch [CG], distillers\u27 grain mulch [DG], creeping red fescue [CRF], non-sprayed control [NSC], and glyphosate [GLY]) and three inter-row treatments (creeping red fescue [CRF], Kentucky bluegrass [KB], and resident vegetation [RV]). Treatments were established in 2010-2011 and measurements were conducted during 2012 and 2013 on 5- and 6-year- old vines. Soil temperatures were mostly higher under mulches and lower under intra- row groundcovers, compared to GLY. Weed cover in CG, DG, and CRF treatments was the same or less than GLY. At most sampling dates, inter-row soil moisture was lowest under KB. Intra-row soil moisture was highest under DG mulch and lowest under CRF and NSC; CG had the same or lower soil moisture than GLY. Surprisingly, we did not detect differences in mid-day photosynthetically active radiation (PAR) reflectance, despite visual differences among the intra-row treatments. Mid-day vine water potential did not differ among treatments. We concluded it is not necessary to maintain a bare soil strip under established vines in this region, where soil fertility and moisture are non-limiting

Abundance and species composition of non-geniculate coralline red algae epiphytic on the South African populations of the rocky shore seagrass Thalassodendron leptocaule M.C. Duarte, Bandeira & Romeiras

Seagrasses support a great diversity of epiphytic organisms and new research has shown that non-geniculate coralline red algae are important occupiers of space on the fronds of seagrasses. Except for a few scant records, there are no detailed published accounts of non-geniculate coralline algae epiphytic on seagrasses in South Africa. The seagrass Thalassodendron leptocaule (previously known as Thalassodendron ciliatum) is unique among southern African seagrasses in that it occurs on exposed rocky outcrops along the Mozambique and north eastern South African coast; most other seagrasses are restricted to sheltered bays and estuaries. Here we present descriptions of three species of non-geniculate coralline red algae which we have identified growing epiphytically on this seagrass in northern KwaZulu-Natal: Hydrolithon farinosum, Pneophyllum amplexifrons and Synarthrophyton patena. Two of the corallines (P. amplexifrons and S. patena) were restricted to the seagrass' stems while the third (H. farinosum) occurred only on the leaves. Of the three coralline epiphytes, P. amplexifrons contributed most to the biomass (average wet weight per plant 0.6±1.18 g); its wet weight, however, varied between habitats. Hydrolithon farinosum and other smaller turf algae amounted to no more than 0.1 g (wet weight) per leaf. Synarthrophyton patena was far more sparsely evident and contributed to less than 0.1 g (wet weight) per stem. Pneophyllum amplexifrons and H. farinosum appear to be pioneer epiphytes and form additional surfaces onto which other seaweed epiphytes attach and grow. Distribution of these epiphytes is explained by the longevity of the stems and leaves of the seagrass.Web of Scienc

How robust are community-based plant bioindicators? Empirical testing of the relationship between Ellenberg values and direct environmental measures in woodland communities

There are several community-based bioindicator systems that use species presence or abundance data as proxies for environmental variables. One example is the Ellenberg system, whereby vegetation data are used to estimate environmental soil conditions. Despite widespread use of Ellenberg values in ecological research, the correlation between bioindicated values and actual values is often an implicit assumption rather than based on empirical evidence. Here, we correlate unadjusted and UK-adjusted Ellenberg values for soil moisture, pH, and nitrate in relation to direct environmental measures for 50 woodland sites in the UK, which were subject to repeat sampling. Our results show the accuracy of Ellenberg values is parameter specific; pH values were a good proxy for direct environmental measures but this was not true for soil moisture, when relationships were weak and non-significant. For nitrates, there were important seasonal differences, with a strong positive logarithmic relationship in the spring but a non-significant (and negative) correlation in summer. The UK-adjusted values were better than, or equivalent to, Ellenberg’s original ones, which had been quantified originally for Central Europe, in all cases. Somewhat surprisingly, unweighted values correlated with direct environmental measures better than did abundance-weighted ones. This suggests that the presence of rare plants can be highly important in accurate quantification of soil parameters and we recommend using an unweighted approach. However, site profiles created only using rare plants were inferior to profiles based on the whole plant community and thus cannot be used in isolation. We conclude that, for pH and nitrates, the Ellenberg system provides a useful estimate of actual conditions, but recalibration of moisture values should be considered along with the effect of seasonality on the efficacy of the system