scholarly journals Adaptive management plans rooted in quantitative ecological predictions of ecosystem processes: putting monitoring data to practical use

2021 ◽  
pp. 1-6
Author(s):  
Christian Damgaard

Summary The adoption of adaptive management plans has been advocated in order to ensure the most effective management of natural habitats. Here, it is demonstrated how a hierarchical structural equation model that is fitted to temporal ecological monitoring data from a number of sites may be used to generate quantitative local ecological predictions and how these predictions may form the basis of adaptive management plans. Local ecological predictions will be made for the cover of the dwarf shrub cross-leaved heath (Erica tetralix) on Danish wet heathlands, which is an indicator of the conservation status of wet heathlands under different management scenarios. Based on a realistic example, the model predictions conclude that grazing by livestock on wet heathlands with a relatively low cover of cross-leaved heath cannot be recommended as the only management practice. Generally, ecological monitoring data may be used to generate quantitative and credible local adaptive management plans where uncertainty is taken into account.

2020 ◽  
Author(s):  
Christian Damgaard

AbstractIt is demonstrated how a hierarchical structural equation model that is fitted to temporal ecological monitoring data from a number of sites may be used to generate local ecological predictions and how these local ecological predictions may form the basis of adaptive management plans. Local ecological predictions will be made for the cover of cross-leaved heath on Danish wet heathlands, which is one of the indicators that determine the conservation status of wet heathlands under different management scenarios. Based on a realistic example, the model predictions concludes that grazing by domestic herbivores on wet heathlands with a relatively low cover cross-leaved heath cannot be recommended as the only management practice. Generally, it is recommended to use ecological monitoring data to generate quantitative and credible local adaptive management plans where the uncertainty is taken into account.


2021 ◽  
Author(s):  
Jiajia Liu ◽  
Xue-Jun Ge

Abstract Ecological scale has been widely assumed to influence various biodiversity-productivity relationships in ecological communities; however, its robustness has not been extensively studied. In this study, we tested the scale dependency of biodiversity-productivity relationships by evaluating their direct linkages while considering other confounders, and simultaneously incorporating functional traits and interspecific phylogenetic relationships. We surveyed sixty quadrats each with an area of 0.25 m2 in three different meadows located along an elevational gradient in Yulong Mountain, China. We calculated different biodiversity parameters (richness, evenness, functionality, and phylogeny), and evaluated the chemical properties of soil from all quadrats, correlating their relationships with plant productivity at the local and regional scale. The direct and indirect relationships of biodiversity and productivity were evaluated using structural equation modeling. The biodiversity-productivity relationships were weak and inconsistent at the local scale, whereas some biodiversity metrics (richness, functional, and phylogenetic) showed either strong positive or negative relationships with productivity at the regional scale. However, a direct correlation between productivity and variables such as soil pH and community-weighted mean leaf carbon content was observed in the structural equation model reconstructed. Our study indicates that the scale dependency of biodiversity-productivity relationships in natural habitats may not be as strong as it may have been previously perceived, in case of taxonomic, functional, and phylogenetic diversity, respectively. Our study emphasizes the necessity to account for the confounding effects of abiotic factors when evaluating biodiversity-productivity relationship in natural habitats at regional or even worldwide scales.


Author(s):  
Jinjie Li ◽  
Jiayin Qi ◽  
Lianren Wu ◽  
Nan Shi ◽  
Xu Li ◽  
...  

Why does the continued use of social commerce platforms fail to promote consumer wellbeing? This study explores the roles of influencers, informational incentives and fear of missing out (FoMO) in the relationships between social commerce platform use and consumer mental health. Data were obtained through questionnaires, as well as constructing a research model. Statistical analysis and path analysis of the structural equation model were performed by the software IBM SPSS and AMOS, and the following results were obtained. (1) Influencer expertise and interactivity, informational incentives and FoMO have a significant impact on consumers’ continued use of social commerce platforms. (2) Materialism has no significant effect on consumer social commerce platform use. (3) FoMO mediates the relationships between informational incentives and continued use of social commerce platforms. (4) Consumers’ continuous use of social commerce platforms has a strong relationship with mental health. (5) Continued use of social commerce platforms can lead to intense social engagement, as well as more severe outcomes such as psychological anxiety and compulsive buying. The findings of the paper have important implications for the development of social business theory and management practice.


2020 ◽  
Vol 36 (3) ◽  
pp. 500-509
Author(s):  
Hannah G. Bosley ◽  
Devon B. Sandel ◽  
Aaron J. Fisher

Abstract. Generalized anxiety disorder (GAD) is associated with worry and emotion regulation difficulties. The contrast-avoidance model suggests that individuals with GAD use worry to regulate emotion: by worrying, they maintain a constant state of negative affect (NA), avoiding a feared sudden shift into NA. We tested an extension of this model to positive affect (PA). During a week-long ecological momentary assessment (EMA) period, 96 undergraduates with a GAD analog provided four daily measurements of worry, dampening (i.e., PA suppression), and PA. We hypothesized a time-lagged mediation relationship in which higher worry predicts later dampening, and dampening predicts subsequently lower PA. A lag-2 structural equation model was fit to the group-aggregated data and to each individual time-series to test this hypothesis. Although worry and PA were negatively correlated in 87 participants, our model was not supported at the nomothetic level. However, idiographically, our model was well-fit for about a third (38.5%) of participants. We then used automatic search as an idiographic exploratory procedure to detect other time-lagged relationships between these constructs. While 46 individuals exhibited some cross-lagged relationships, no clear pattern emerged across participants. An alternative hypothesis about the speed of the relationship between variables is discussed using contemporaneous correlations of worry, dampening, and PA. Findings suggest heterogeneity in the function of worry as a regulatory strategy, and the importance of temporal scale for detection of time-lagged effects.


2019 ◽  
Vol 35 (6) ◽  
pp. 823-833 ◽  
Author(s):  
Desiree Thielemann ◽  
Felicitas Richter ◽  
Bernd Strauss ◽  
Elmar Braehler ◽  
Uwe Altmann ◽  
...  

Abstract. Most instruments for the assessment of disordered eating were developed and validated in young female samples. However, they are often used in heterogeneous general population samples. Therefore, brief instruments of disordered eating should assess the severity of disordered eating equally well between individuals with different gender, age, body mass index (BMI), and socioeconomic status (SES). Differential item functioning (DIF) of two brief instruments of disordered eating (SCOFF, Eating Attitudes Test [EAT-8]) was modeled in a representative sample of the German population ( N = 2,527) using a multigroup item response theory (IRT) and a multiple-indicator multiple-cause (MIMIC) structural equation model (SEM) approach. No DIF by age was found in both questionnaires. Three items of the EAT-8 showed DIF across gender, indicating that females are more likely to agree than males, given the same severity of disordered eating. One item of the EAT-8 revealed slight DIF by BMI. DIF with respect to the SCOFF seemed to be negligible. Both questionnaires are equally fair across people with different age and SES. The DIF by gender that we found with respect to the EAT-8 as screening instrument may be also reflected in the use of different cutoff values for men and women. In general, both brief instruments assessing disordered eating revealed their strengths and limitations concerning test fairness for different groups.


2010 ◽  
Vol 15 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Remus Ilies ◽  
Timothy A. Judge ◽  
David T. Wagner

This paper focuses on explaining how individuals set goals on multiple performance episodes, in the context of performance feedback comparing their performance on each episode with their respective goal. The proposed model was tested through a longitudinal study of 493 university students’ actual goals and performance on business school exams. Results of a structural equation model supported the proposed conceptual model in which self-efficacy and emotional reactions to feedback mediate the relationship between feedback and subsequent goals. In addition, as expected, participants’ standing on a dispositional measure of behavioral inhibition influenced the strength of their emotional reactions to negative feedback.


Methodology ◽  
2014 ◽  
Vol 10 (4) ◽  
pp. 138-152 ◽  
Author(s):  
Hsien-Yuan Hsu ◽  
Susan Troncoso Skidmore ◽  
Yan Li ◽  
Bruce Thompson

The purpose of the present paper was to evaluate the effect of constraining near-zero parameter cross-loadings to zero in the measurement component of a structural equation model. A Monte Carlo 3 × 5 × 2 simulation design was conducted (i.e., sample sizes of 200, 600, and 1,000; parameter cross-loadings of 0.07, 0.10, 0.13, 0.16, and 0.19 misspecified to be zero; and parameter path coefficients in the structural model of either 0.50 or 0.70). Results indicated that factor pattern coefficients and factor covariances were overestimated in measurement models when near-zero parameter cross-loadings constrained to zero were higher than 0.13 in the population. Moreover, the path coefficients between factors were misestimated when the near-zero parameter cross-loadings constrained to zero were noteworthy. Our results add to the literature detailing the importance of testing individual model specification decisions, and not simply evaluating omnibus model fit statistics.


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