scholarly journals Understanding the value of plant diversity for ecosystem functioning through niche theory

2016 ◽  
Vol 283 (1844) ◽  
pp. 20160536 ◽  
Author(s):  
Lindsay A. Turnbull ◽  
Forest Isbell ◽  
Drew W. Purves ◽  
Michel Loreau ◽  
Andy Hector
Keyword(s):  
Plant Diversity ◽  
Real World ◽  
Ecosystem Functioning ◽  
Species Coexistence ◽  
Future Research ◽  
Biological Processes ◽  
Niche Theory ◽  
Natural Ecosystems ◽  
Empirical Results ◽  
Simple Mapping

Biodiversity experiments have generated robust empirical results supporting the hypothesis that ecosystems function better when they contain more species. Given that ecosystems provide services that are valued by humans, this inevitably suggests that the loss of species from natural ecosystems could diminish their value. This raises two important questions. First, will experimental results translate into the real world, where species are being lost at an alarming rate? And second, what are the benefits and pitfalls of such valuation exercises? We argue that the empirical results obtained in experiments are entirely consistent with well-established theories of species coexistence. We then examine the current body of work through the lens of niche theory and highlight where closer links with theory could open up opportunities for future research. We argue that niche theory predicts that diversity–functioning relationships are likely to be stronger (and require more species) in the field than in simplified experimental settings. However, we caution that while many of the biological processes that promote coexistence can also generate diversity–function relationships, there is no simple mapping between the two. This implies that valuation exercises need to proceed with care.

scholarly journals Impacts of Land-Use Changes on Vegetation and Ecosystem Functioning: Old-Field Secondary Succession

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 990
Author(s):  
Javier Pérez-Hernández ◽  
Rosario G. Gavilán
Keyword(s):  
Plant Communities ◽  
Ecosystem Functioning ◽  
Secondary Succession ◽  
Species Coexistence ◽  
Human Impacts ◽  
Soil Seed Bank ◽  
Land Use Changes ◽  
Dispersal Limitation ◽  
Point Of View ◽  
Old Field

The study of ecological succession to determine how plant communities re-assemble after a natural or anthropogenic disturbance has always been an important topic in ecology. The understanding of these processes forms part of the new theories of community assembly and species coexistence, and is attracting attention in a context of expanding human impacts. Specifically, new successional studies provide answers to different mechanisms of community assemblage, and aim to define the importance of deterministic or stochastic processes in the succession dynamic. Biotic limits, which depend directly on biodiversity (i.e., species competition), and abiotic filtering, which depends on the environment, become particularly important when they are exceeded, making the succession process more complicated to reach the previous disturbance stage. Plant functional traits (PFTs) are used in secondary succession studies to establish differences between abandonment stages or to compare types of vegetation or flora, and are more closely related to the functioning of plant communities. Dispersal limitation is a PFT considered an important process from a stochastic point of view because it is related to the establishing of plants. Related to it the soil seed bank plays an important role in secondary succession because it is essential for ecosystem functioning. Soil compounds and microbial community are important variables to take into account when studying any succession stage. Chronosequence is the best way to study the whole process at different time scales. Finally, our objective in this review is to show how past studies and new insights are being incorporated into the basis of classic succession. To further explore this subject we have chosen old-field recovery as an example of how a number of different plant communities, including annual and perennial grasslands and shrublands, play an important role in secondary succession.

scholarly journals Revisiting the CompCars Dataset for Hierarchical Car Classification: New Annotations, Experiments, and Results

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 596
Author(s):  
Marco Buzzelli ◽  
Luca Segantin
Keyword(s):  
Real World ◽  
High Performance ◽  
Ad Hoc ◽  
Future Research ◽  
Levels Of Detail ◽  
Excellent Starting Point ◽  
Starting Point ◽  
Hierarchical Nature ◽  
Multiple Levels ◽  
Entire Dataset

We address the task of classifying car images at multiple levels of detail, ranging from the top-level car type, down to the specific car make, model, and year. We analyze existing datasets for car classification, and identify the CompCars as an excellent starting point for our task. We show that convolutional neural networks achieve an accuracy above 90% on the finest-level classification task. This high performance, however, is scarcely representative of real-world situations, as it is evaluated on a biased training/test split. In this work, we revisit the CompCars dataset by first defining a new training/test split, which better represents real-world scenarios by setting a more realistic baseline at 61% accuracy on the new test set. We also propagate the existing (but limited) type-level annotation to the entire dataset, and we finally provide a car-tight bounding box for each image, automatically defined through an ad hoc car detector. To evaluate this revisited dataset, we design and implement three different approaches to car classification, two of which exploit the hierarchical nature of car annotations. Our experiments show that higher-level classification in terms of car type positively impacts classification at a finer grain, now reaching 70% accuracy. The achieved performance constitutes a baseline benchmark for future research, and our enriched set of annotations is made available for public download.

A Critical Review of the Biological Processes in the Chemical Absorption-biological Reduction Integrated System for NO Removal

2021 ◽  
Vol 07 ◽  
Author(s):  
Wei Li
Keyword(s):  
Catalytic Reduction ◽  
Low Cost ◽  
Reduction Process ◽  
Integrated System ◽  
Future Research ◽  
Small Scale ◽  
Biological Processes ◽  
Chemical Absorption ◽  
Biological Reduction ◽  
Biological Reaction

: Exploring low-cost, green and safe technologies to provide an alternative to the conventional selective catalytic reduction process is key to the control of NOx emitted from small-scale boilers and other industrial processes. To meet the demand, the chemical absorption-biological reduction integrated system has been developing recently. chemical absorption-biological reduction integrated system applies Fe(II)EDTA for NO absorption and iron-reducing and denitrifying bacteria for absorbent regeneration. Many studies have focused on the enhancements of mass transfer and biological reaction, among which the biological processes were the rate-limiting steps. This review summarizes the current researches on the biological processes in the CABR system, which focuses on the mechanism and enhancement of biochemical reactions, and provides the possible directions of future research.

scholarly journals Ammonium as a Driving Force of Plant Diversity and Ecosystem Functioning: Observations Based on 5 Years' Manipulation of N Dose and Form in a Mediterranean Ecosystem

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e92517 ◽  
Author(s):  
Teresa Dias ◽  
Adelaide Clemente ◽  
Maria Amélia Martins-Loução ◽  
Lucy Sheppard ◽  
Roland Bobbink ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Ecosystem Functioning ◽  
Driving Force ◽  
Mediterranean Ecosystem ◽  
N Dose

scholarly journals Plant Phenology and Its Anthropogenic and Natural Influencing Factors in Densely Populated Areas During the Economic Transition Period of China

2022 ◽  
Vol 9 ◽  
Author(s):  
Peijun Ju ◽  
Wenchao Yan ◽  
Jianliang Liu ◽  
Xinwei Liu ◽  
Liangfeng Liu ◽  
...  
Keyword(s):  
Climate Change ◽  
Economic Transition ◽  
Transition Period ◽  
Growing Season ◽  
Plant Phenology ◽  
Future Research ◽  
Urban Management ◽  
Climate Factors ◽  
Natural Ecosystems ◽  
The Impact

As a sensitive, observable, and comprehensive indicator of climate change, plant phenology has become a vital topic of global change. Studies about plant phenology and its responses to climate change in natural ecosystems have drawn attention to the effects of human activities on phenology in/around urban regions. The key factors and mechanisms of phenological and human factors in the process of urbanization are still unclear. In this study, we analyzed variations in xylophyta phenology in densely populated cities during the fast urbanization period of China (from 1963 to 1988). We assessed the length of the growing season affected by the temperature and precipitation. Temperature increased the length of the growing season in most regions, while precipitation had the opposite effect. Moreover, the plant-growing season is more sensitive to preseason climate factors than to annual average climate factors. The increased population reduced the length of the growing season, while the growing GDP increased the length of the growing season in most regions (8 out of 13). By analyzing the impact of the industry ratio, we found that the correlation between the urban management of emerging cities (e.g., Chongqing, Zhejiang, and Guizhou) and the growing season is more significant, and the impact is substantial. In contrast, urban management in most areas with vigorously developed heavy industry (e.g., Heilongjiang, Liaoning, and Beijing) has a weak and insignificant effect on plant phenology. These results indicate that different urban development patterns can influence urban plant phenology. Our results provide some support and new thoughts for future research on urban plant phenology.

scholarly journals 19-Hydroxy steroids in the aromatase reaction: Review on expression and potential functions

2021 ◽  
Author(s):  
Tatjana Abaffy ◽  
Hiroaki Matsunami
Keyword(s):  
Adrenal Glands ◽  
Ovarian Function ◽  
Scientific Evidence ◽  
Future Research ◽  
Analytical Sensitivity ◽  
Biological Processes ◽  
Search Terms ◽  
Pathological Conditions ◽  
Pubmed Database ◽  
The Brain

Abstract Scientific evidence related to the aromatase reaction in various biological processes spanning from mid-1960 is abundant, however, as our analytical sensitivity increases, a new look at the old chemical reaction is necessary. Here, we review an irreversible aromatase reaction from the substrate androstenedione. It proceeds in 3 consecutive steps. In the first two steps, 19-hydroxy steroids are produced. They can dissociate from the enzyme complex and either accumulate in tissues or enter the blood.In this review, we want to highlight the potential importance of these 19-hydroxy steroids in various physiological and pathological conditions. We focus primarily on 19-hydroxy steroids, and in particular on the 19-hydroxyandrostenedione produced by the incomplete aromatase reaction. Using a PubMed database and search terms aromatase reaction,19-hydroxylation of androgens and steroid measurements, we detail the chemistry of the aromatase reaction and list previous and current methods used to measure 19-hydroxy steroids. We present the evidence of the existence of 19-hydroxy steroids in the brain tissue, ovaries, testes, adrenal glands, prostate cancer and also during pregnancy and parturition and in Cushing’s disease. Based on the available literature, a potential involvement of 19-hydroxy steroids in the brain differentiation process, sperm motility, ovarian function, and hypertension is suggested and warrant future research.We hope that with the advancement of highly specific and sensitive analytical methods, future research into 19-hydroxy steroids will be encouraged, as much remains to be learned and discovered.

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