Relating stream physical habitat condition and concordance of biotic productivity across multiple taxa

2008 ◽  
Vol 65 (12) ◽  
pp. 2667-2677 ◽  
Author(s):  
S. Mažeika P. Sullivan ◽  
Mary C. Watzin
Keyword(s):  
Pearson Correlation ◽  
Principal Component ◽  
Trophic Levels ◽  
Fish Biomass ◽  
Physical Habitat ◽  
Habitat Condition ◽  
Assessment Scores ◽  
Combined Use ◽  
Ceryle Alcyon ◽  
Condition Assessments

To explore the potential of assessments of stream geomorphic condition and habitat quality in evaluating lotic productivity, we investigated concordance of stream biotic productivity (aquatic macroinvertebrates, crayfish, fish, and belted kingfishers ( Ceryle alcyon )) and their physical habitat correlates in 18 streams in the Champlain Valley, Vermont, USA. Pearson correlation analysis indicated significant concordance between macroinvertebrate density and fish biomass (r = 0.76), between the density of macroinvertebrates in the orders Ephemeroptera, Plecoptera, and Trichoptera and fish biomass (r = 0.81), and between fish biomass and kingfisher brood weight (r = 0.54). We used principal component analysis followed by linear regression to investigate relationships between physical habitat condition and biotic productivity and to identify key components of physical habitat condition assessments. Our analysis supported the combined use of geomorphic and habitat assessments as a comprehensive indicator of stream physical habitat condition. We found relationships between habitat assessment scores and productivity measures of all taxa except crayfish, suggesting similar responses to physical condition across trophic levels. Our results encourage the use of additional taxa, in addition to widely used macroinvertebrate metrics, as indicators of the composite effects of physical habitat impairment in stream ecosystems.

scholarly journals Bioprospecting of Sechium spp. varieties for the selection of characters with pharmacological activity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
María Isabel Iñiguez-Luna ◽  
Jorge Cadena-Iñiguez ◽  
Ramón Marcos Soto-Hernández ◽  
Francisco Javier Morales-Flores ◽  
Moisés Cortes-Cruz ◽  
...  
Keyword(s):  
Cell Lines ◽  
Proliferative Activity ◽  
Meta Analysis ◽  
Pearson Correlation ◽  
Statistical Significance ◽  
Economic Value ◽  
Principal Component ◽  
Malignant Cell ◽  
Length Polymorphisms ◽  
Relevant Variables

AbstractBioprospecting identifies new sources of compounds with actual or potential economic value that come from biodiversity. An analysis was performed regarding bioprospecting purposes in ten genotypes of Sechium spp., through a meta-analysis of 20 information sources considering different variables: five morphological, 19 biochemical, anti-proliferative activity of extracts on five malignant cell lines, and 188 polymorphic bands of amplified fragment length polymorphisms, were used in order to identify the most relevant variables for the design of genetic interbreeding. Significant relationships between morphological and biochemical characters and anti-proliferative activity in cell lines were obtained, with five principal components for principal component analysis (SAS/ETS); variables were identified with a statistical significance (< 0.7 and Pearson values ≥ 0.7), with 80.81% of the accumulation of genetic variation and 110 genetic bands. Thirty-nine (39) variables were recovered using NTSYSpc software where 30 showed a Pearson correlation (> 0.5) and nine variables (< 0.05), Finally, using a cladistics analysis approach highlighted 65 genetic bands, in addition to color of the fruit, presence of thorns, bitter flavor, piriform and oblong shape, and also content of chlorophylls a and b, presence of cucurbitacins, and the IC50 effect of chayote extracts on the four cell lines.

scholarly journals Towards Understanding Variability in Droughts in Response to Extreme Climate Conditions over the Different Agro-Ecological Zones of Pakistan

2021 ◽  
Vol 13 (12) ◽  
pp. 6910
Author(s):  
Adil Dilawar ◽  
Baozhang Chen ◽  
Arfan Arshad ◽  
Lifeng Guo ◽  
Muhammad Irfan Ehsan ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Principal Component ◽  
Mitigation Strategies ◽  
Precipitation Extremes ◽  
Climate Mitigation ◽  
Mean Annual Temperature ◽  
Climate Extreme ◽  
Ecological Zones ◽  
The Mean ◽  
Agro Ecological Zones

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.

scholarly journals Key soil parameters affecting the survival of Panax notoginseng under continuous cropping

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wumei Xu ◽  
Fengyun Wu ◽  
Haoji Wang ◽  
Linyan Zhao ◽  
Xue Liu ◽  
...  
Keyword(s):  
Soil Ph ◽  
Pearson Correlation ◽  
Principal Component ◽  
Panax Notoginseng ◽  
Soil Parameters ◽  
Continuous Cropping ◽  
Poor Growth ◽  
Available N ◽  
The Poor ◽  
Replant Problem

AbstractNegative plant-soil feedbacks lead to the poor growth of Panax notoginseng (Sanqi), a well-known herb in Asia and has been used worldwide, under continuous cropping. However, the key soil parameters causing the replant problem are still unclear. Here we conducted a field experiment after 5-year continuous cropping. Sanqi seedlings were cultivated in 7 plots (1.5 m × 2 m), which were randomly assigned along a survival gradient. In total, 13 important soil parameters were measured to understand their relationship with Sanqi’s survival. Pearson correlation analysis showed that 6 soil parameters, including phosphatase, urease, cellulase, bacteria/fungi ratio, available N, and pH, were all correlated with Sanqi’s survival rate (P < 0.05). Principal component analysis (PCA) indicated that they explained 61% of the variances based on the first component, with soil pH being closely correlated with other parameters affecting Sanqi’s survival. The optimum pH for Sanqi growth is about 6.5, but the mean soil pH in the study area is 5.27 (4.86–5.68), therefore it is possible to ameliorate the poor growth of Sanqi by increasing soil pH. This study may also help to reduce the replant problem of other crops under continuous cropping since it is widespread in agricultural production.

PSXIII-26 Supplementation with a polyphenolic pine bark extract reduces ammonia nitrogen production in a RUSITEC system as determined by principal component analysis

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 435-436
Author(s):  
Nelson Vera ◽  
Constanza Gutierrez ◽  
Pamela Williams ◽  
Cecilia Fuentealba ◽  
Rodrigo Allende ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Repeated Measures ◽  
Pearson Correlation ◽  
Principal Component ◽  
Component Analysis ◽  
Ammonia Nitrogen ◽  
Pine Bark ◽  
Bark Extract ◽  
Ruminal Fermentation ◽  
Fermentation Parameters

Abstract The aim of the study was to correlate the effects of supplementation with a polyphenolic pine bark extract (PBE) in diets with different forage to concentrate (F:C) ratio on methane (CH4), ammonia nitrogen (NH3–N) production and ruminal fermentation parameters using the Rumen Simulation Technique (RUSITEC). The experimental diets were F:C 70:30 (HF) or F:C 30:70 (HC) with or without 2% PBE on a DM basis. The four diets were isoproteic (15% CP), with similar OM (HF 94% and HC 96%), but different NDF (HF 40% and HC 25%). The treatments, in duplicate, were assigned in an 8 fermenter RUSITEC apparatus. Incubations were run twice, with 5 days of sampling after 10 days adaptation. The experimental design was a 2x2 factorial arrangement in a randomized complete block with repeated measures. Pearson correlation and principal component analysis (PCA) were conducted to elucidate relationships among PBE total polyphenols (TP) and the variables evaluated. The TP was highly correlated with NH3–N (r = –0.98; P &lt; 0.001) and butyrate (r = –0.85; P &lt; 0.001), and had a high correlation with propionate (r = 0.75; P &lt; 0.001) and acetate (r = 0.68; P = 0.001). Correlation with total VFA was moderate (r = –0.59; P = 0.006), and CH4 yield and IVDMD there were not correlated (r ≤ –0.07; P ≥ 0.188). The PCA (KMO = 0.655; BTS &lt; 0.001) shows that 75.2% of the total variation is explained by the first two principal components (PC1 = 46.5% and PC2 = 28.7%). In the score plot, PC1 discriminated between diets with and without PBE, while the PC2 separated based on NDF. The loading plot showed that TP and propionate were clustered, and had inverse directions to NH3–N. In conclusion, the PBE supplementation reduces NH3–N production in a RUSITEC system without decreasing CH4 yield or negatively affecting ruminal fermentation parameters.

scholarly journals No-tillage system participatory quality index

2020 ◽  
Vol 24 (2) ◽  
pp. 128-133 ◽  
Author(s):  
Tiago S. Telles ◽  
Ana J. Righetto ◽  
Marco A. P. Lourenço ◽  
Graziela M. C. Barbosa
Keyword(s):  
Principal Component Analysis ◽  
Cluster Analysis ◽  
Crop Rotation ◽  
Quality Index ◽  
Pearson Correlation ◽  
Principal Component ◽  
Component Analysis ◽  
Soil Tillage ◽  
No Tillage ◽  
Tillage System

ABSTRACT The no-tillage system participatory quality index aims to evaluate the quality and efficiency of soil management under no-tillage systems and consists of a weighted sum of eight indicators: intensity of crop rotation, diversity of crop rotation, persistence of crop residues in the soil surface, frequency of soil tillage, use of agricultural terraces, evaluation of soil conservation, balance of soil fertilization and time of adoption of the no-tillage system. The aim of this study was to assess the extent to which these indicators correlate with the no-tillage system participatory quality index and to characterize the farmers who participated in the research. The data used were provided by ITAIPU Binacional for the indicators of the no-tillage system participatory quality index II. Descriptive analyses were performed, and the Pearson correlation coefficient between the index and each indicator was calculated. To assess the relationship between the indicators and the farmers’ behavior toward the indicators, principal component analysis and cluster analysis were performed. Although all correlations are significant at p-value ≤ 0.05, some correlations are weak, indicating a need for improvement of the index. The principal component analysis identified three principal components, which explained 66% of the variability of the data, and the cluster analysis separated the 121 farmers into five groups. It was verified that the no-tillage system participatory quality index II has some limitations and should therefore be reevaluated to increase its efficiency as an indicator of the quality of the no-tillage system.

scholarly journals Arthropod community at different altitudes in Gunung Halimun-Salak National Park, Western Java, Indonesia

2019 ◽  
Vol 20 (6) ◽  
Author(s):  
NOOR FARIKHAH HANEDA ◽  
IWAN HILWAN ◽  
EWI IRFANI
Keyword(s):  
National Park ◽  
Pearson Correlation ◽  
Principal Component ◽  
Environmental Parameters ◽  
Soil Arthropods ◽  
Arthropod Community ◽  
Total N ◽  
Organic C ◽  
Soil Arthropod ◽  
Different Altitudes

Abstract. Haneda NF, Hilwan I, Irfani E. 2019. Arthropod community at different altitudes in Gunung Halimun-Salak National Park, Western Java, Indonesia. Biodiversitas 20: 1735-1742. Gunung Halimun Salak National Park (GHSNP) stores high biodiversity both from its flora and fauna. Parts of the diversity that have not been widely explored are soil arthropods at different altitudes. The aim of this study was to analyze soil arthropod community and the correlation between the attributes of soil arthropods and the environmental factors. The soil arthropods were collected using pitfall traps, placed in several altitudes, i.e., 500 m, 700 m, 900 m, 1100 m, 1300 m, 1500 m, and 1700 m . The attributes of community and environmental parameters were analyzed using Pearson correlation and principal component analysis. The result showed that family Formicidae dominated the soil arthropod community. The diversity of arthropods increased with increasing altitudes. The habitat at the altitudes of 1500 m, 1300 m and 1100 m had a dense canopy, thick litter and high total N and organic C. There was positive correlation between the attributes of soil arthropod community and environment variables.

A Knowledge Framework for Development

2012 ◽  
pp. 244-265
Author(s):  
Ravi S. Sharma ◽  
Ganesh Chandrasekar ◽  
Bharathkumar Vaitheeswaran
Keyword(s):  
Pearson Correlation ◽  
Knowledge Society ◽  
Relevant Literature ◽  
Secondary Data ◽  
Technological Parameters ◽  
Knowledge Framework ◽  
Assessment Scores ◽  
Knowledge Based ◽  
Proxy Indicators ◽  
Political Economic

In this article, the authors investigate the diverse dimensions of a knowledge society. First, the relevant literature on post industrial societies is reviewed to identify the key constituents of successful growth and development. The authors then propose a 10-dimension framework within political, economic, social and technological parameters that describe the state of evolution of a given knowledge society. Knowledge assessment scores, human development indices, technology readiness scores and competitiveness scores are selected as composite indicators of knowledge societies. Proxy indicators are assigned for the dimensions, and secondary data was gathered from reputed international sources. Partial Pearson Correlation Analysis was done between the proxy indicators and the composite scales to determine the direction and strength of relationships. Hygiene factors and competitive factors of a knowledge society are distilled from the empirical results and recommendations are suggested to address some areas of concern when pursuing policies for knowledge based development.

scholarly journals Towards End-2-End modelling in a consistent NPZD-F modelling framework (ECOSMOE2E_vs1.0): Application to the North Sea and Baltic Sea

2018 ◽  
Author(s):  
Ute Daewel ◽  
Corinna Schrum ◽  
Jed Macdonald
Keyword(s):  
Baltic Sea ◽  
North Sea ◽  
Food Chain ◽  
Current System ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Production Model ◽  
Fish Mortality ◽  
Fish Biomass ◽  
Trophic Chain

Abstract. Coupled physical-biological models usually resolve only parts of the trophic food chain and hence, run the risk of neglecting relevant ecosystem processes. Additionally, this imposes a closure term problem at the respective “ends” of the considered trophic levels. Here we propose a consistent NPZD-Fish modelling approach (ECOSMO E2E) to address the above-mentioned problem in lower trophic ecosystem modelling, and to understand how the implementation of higher trophic levels in a NPZD model affects the simulated response of the combined North Sea and Baltic Sea ecosystem. On the basis of the coupled ecosystem model ECOSMO II we implemented one functional group that represents fish and one group representing macrobenthos in the 3d model formulation. Both groups are linked to the lower trophic levels and to each other via predator-prey relationships. The model allows investigating bottom-up impacts on primary and secondary production and cumulative fish biomass dynamics, but also top-down mechanisms on the lower trophic level production. Model results for a ten-year long simulation period (1980–1989) were analysed and discussed with respect to the observed pattern. To address the relevance of the newly implemented trophic levels for the simulated model response, we compare the performance of the ECOSMO E2E to a respective truncated NPZD model (ECOSMO II), which simulated the same time period. Additionally, we performed scenario tests to analyse the new role of the zooplankton mortality closure term in the truncated NPZD and the fish mortality term in the end-to-end model, which summarizes pressure imposed on the system by fisheries and mortality imposed by apex predators. We found that the model-simulated macrobenthos and fish spatial and seasonal pattern agree well with current system understanding. Considering a dynamic fish component in the ecosystem model resulted in slightly improved model performance with respect to representation of spatial and temporal variations in nutrients, changes in modelled plankton seasonality and nutrient profiles. Model sensitivity scenarios showed that changes in the zooplankton mortality parameter are transferred up and down the trophic chain with little attenuation of the signal, while major changes in fish mortality and in fish biomass cascade down the food chain.

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