scholarly journals The Significance of Aggregation Methods in Functional Group Modeling

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1560
Author(s):  
Huan Zhang ◽  
Herman H. Shugart ◽  
Bin Wang ◽  
Manuel Lerdau
Keyword(s):  
Functional Groups ◽  
Computational Models ◽  
Functional Group ◽  
Environmental Changes ◽  
Deciduous Forest ◽  
Global Climate ◽  
Carbon Dynamics ◽  
Global Scale ◽  
Plant Ecology ◽  
Basic Plant

The growth of forests and the feedbacks between forests and environmental changes are central issues in the planetary carbon cycle, global climate change, and basic plant ecology. A challenge to understanding both growth and feedbacks from local to global scales is that many critical metabolic processes vary among species. An innovation in solving this challenge is the recognition that species can be lumped into “functional groups” based on metabolic similarity, and these functional groups can then be studied in computational models that simulate ecosystem function. Despite the vast resources devoted to functional group studies and the progress made by them, an important logical and biological question has not been formally addressed, “How do the groupings alter the results of modeling studies?” To what extent do modeling results depend on the choices made in aggregating taxa into functional groups. Here, we consider the effects of using different aggregation strategies in simulating the carbon dynamics of a deciduous forest. Understanding the impacts that aggregation strategy has on efforts to simulate regional-to-global-scale forest dynamics offers insights into both ecosystem regulation and model function and addresses this central problem in the study of carbon dynamics.

scholarly journals Diversity of dominant soil bacteria increases with warming velocity at the global scale

2020 ◽  
Author(s):  
Yoshiaki Kanzaki ◽  
Kazuhiro Takemoto
Keyword(s):  
Bacterial Diversity ◽  
Soil Bacteria ◽  
Environmental Changes ◽  
Global Climate ◽  
Aridity Index ◽  
Global Scale ◽  
Soil Bacterial Diversity ◽  
Dominant Soil ◽  
Global Soil ◽  
Soil Bacterial

AbstractUnderstanding global soil bacterial diversity is important because of the key roles soil bacteria play in the global ecosystem. Given the effects of environmental changes (e.g., climate change and human effect) on the diversity of animals and plants, effects on soil bacterial diversity are expected; however, they have been poorly evaluated to date. Thus, in this study, we focused on the soil dominant bacteria because of their global importance and investigated the effects of warming velocity and human activities on their diversity. Using a global dataset of bacteria, we performed spatial analysis to evaluate the effects, while statistically controlling for the potential confounding effects of current climate and geographic parameters with global climate and geographic data. It was demonstrated that the diversity of the dominant soil bacteria was influenced globally by warming velocity (showing significant increases) in addition to aridity index (dryness) and pH. The effects of warming velocity were particularly significant in forests and grasslands. An effect from human activity was also observed, but it was secondary to warming velocity. These findings provide robust evidence, and advance our understanding of the effects of environmental changes (particularly global warming) on soil bacterial diversity at the global scale.

scholarly journals Can bryophyte groups increase functional resolution in tundra ecosystems?

2021 ◽  
Author(s):  
Signe Lett ◽  
Ingibjörg Svala Jónsdóttir ◽  
Antoine Becker-Scarpitta ◽  
Casper T. Christiansen ◽  
Heinjo During ◽  
...  
Keyword(s):  
Functional Groups ◽  
Functional Group ◽  
Environmental Changes ◽  
Intraspecific Variability ◽  
Water Holding Capacity ◽  
Plant Functional Groups ◽  
Relative Contribution ◽  
Grouping Systems ◽  
Water Holding ◽  
Tundra Ecosystems

The relative contribution of bryophytes to plant diversity, primary productivity, and ecosystem functioning increases towards colder climates. Bryophytes respond to environmental changes at the species level, but because bryophyte species are relatively difficult to identify, they are often lumped into one functional group. Consequently, bryophyte function remains poorly resolved. Here, we explore how higher resolution of bryophyte functional diversity can be encouraged and implemented in tundra ecological studies. We briefly review previous bryophyte functional classifications and the roles of bryophytes in tundra ecosystems and their susceptibility to environmental change. Based on shoot morphology and colony organization, we then propose twelve easily distinguishable bryophyte functional groups. To illustrate how bryophyte functional groups can help elucidate variation in bryophyte effects and responses, we compiled existing data on water holding capacity, a key bryophyte trait. Although plant functional groups, can mask potentially high inter- and intraspecific variability, we found better separation of bryophyte functional group means compared to previous grouping systems regarding water holding capacity. This suggests that our bryophyte functional groups truly represent variation in the functional roles of bryophytes in tundra ecosystems. Lastly, we provide recommendations to improve monitoring of bryophyte community changes in tundra study sites.

scholarly journals Diversity of Dominant Soil Bacteria Increases with Warming Velocity at The Global Scale

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 120
Author(s):  
Yoshiaki Kanzaki ◽  
Kazuhiro Takemoto
Keyword(s):  
Bacterial Diversity ◽  
Human Activities ◽  
Soil Bacteria ◽  
Environmental Changes ◽  
Global Climate ◽  
Aridity Index ◽  
Global Scale ◽  
Soil Bacterial Diversity ◽  
Dominant Soil ◽  
Soil Bacterial

Understanding global soil bacterial diversity is important because of its role in maintaining a healthy global ecosystem. Given the effects of environmental changes (e.g., warming and human impact) on the diversity of animals and plants, effects on soil bacterial diversity are expected; however, they have been poorly evaluated at the global scale to date. Thus, in this study, we focused on the dominant soil bacteria, which are likely critical drivers of key soil processes worldwide, and investigated the effects of warming velocity and human activities on their diversity. Using a global dataset of bacteria, we performed spatial analysis to evaluate the effects of warming velocity and human activities, while statistically controlling for the potentially confounding effects of current climate and geographic parameters with global climate and geographic data. We demonstrated that the diversity of the dominant soil bacteria was influenced globally, not only by the aridity index (dryness) and pH but also by warming velocity from the Last Glacial Maximum (21,000 years ago) to the present, showing significant increases. The increase in bacterial diversity with warming velocity was particularly significant in forests and grasslands. An effect of human activity was also observed, but it was secondary to warming velocity. These findings provide robust evidence and advance our understanding of the effects of environmental changes (particularly global warming) on soil bacterial diversity at the global scale.

scholarly journals Phytoplankton functional groups as environmental indicators at a high neotropical mountain reservoir in Colombia

2021 ◽  
Author(s):  
Cristian Hakspiel-Segura ◽  
Betsy Paola Barrios-Galván ◽  
Gabriel Pinilla-Agudelo
Keyword(s):  
Functional Groups ◽  
Suspended Solids ◽  
Functional Group ◽  
Environmental Changes ◽  
Environmental Variability ◽  
Environmental Indicators ◽  
Mixing Conditions ◽  
Chlorella Sp ◽  
Phytoplankton Functional Groups ◽  
Selection Of

Phytoplankton is a fundamental productive component of lentic ecosystems, which also directly reflects environmental variability. This study evaluated the dynamics of phytoplankton in response to the monthly variability of physicochemical properties of a neotropical high Andes reservoir, El Neusa, from July to October 2004. Samples were collected and analyzed for taxonomic identification to species or the lowest possible level and categorized in functional groups (FGs). A total of 111 species of phytoplankton belonging to nine classes and 20 FGs were recorded. Among these phytoplankton classes, Chlorophyceae (36 species), Euglenophyceae (13 species), Bacillariophyceae, (14 species), and Conjugatophyceae (25 species) were the most species-rich and highest in abundance. The overall phytoplankton abundance was largest in August (8.5×104 ±2.7 ×104 ind.L-1) and September (8.9×104 ±4.6×104 ind.L-1); however, the distribution of phytoplankton classes was not statistically different among sampling sites (Friedman-ANOVA; p>0.01)  Chlorella sp. (2.4×104 ±2.0×104 ind.L-1), and Chloromonas grovei (2.5×104 ±4.4×103 ind.L-1), belonging to functional group X1, were dominant, representing together between 54% and 78% of the average monthly abundance. Simple correlations and multivariate analysis between physicochemical variables and phytoplankton revealed that conductivity, pH, and total suspended solids had a key influence on the distribution of both dominant species and FGs. These analyses indicated that hydrological (precipitation and runoff) and water stability (stratification and mixing) conditions determined environmental changes and the selection of phytoplankton functional groups. The main features of the dominant FGs and the trophic state of El Neusa were also discussed. 

scholarly journals Aspectos ecofisiológicos para la conservación de ecosistemas tropicales contrastantes

2017 ◽  
pp. 89
Author(s):  
Aura Azócar ◽  
Fermín Rada ◽  
Carlos García-Nuñez
Keyword(s):  
Water Stress ◽  
Functional Groups ◽  
Functional Group ◽  
Environmental Changes ◽  
Life Forms ◽  
Plant Functional Groups ◽  
Deciduous Tree ◽  
Plant Responses ◽  
Water Factor ◽  
Temperature Water

<p>The identification of plant functional groups allows to evaluate plant properties as: recovering capacity, regeneration and resistence to environmental changes. It is possible to define plant functional groups in the seasonal savana and the high barren plateau taking in to account the ecophysiological plant responses to water stress and daily temperature-water rythmn, respectively. In the savana, although the wooden component is constituted by evergreen and deciduous tree species, they make only a functional group taking in to account their responses to water stress, this is similar in the herbaceous component. Results suggest that a change in environmental factors may generate a floristic replace without major changes in the system function.<br />However, in the high barren plateau, the different life forms also constitute different functional groups according to plant responses to temperature-water factor, suggesting that the substitution of any group will put in danger the preservation of this ecosystem.</p>

scholarly journals Resilience of Epiphytic Lichens to Combined Effects of Increasing Nitrogen and Solar Radiation

2021 ◽  
Vol 7 (5) ◽  
pp. 333
Author(s):  
Lourdes Morillas ◽  
Javier Roales ◽  
Cristina Cruz ◽  
Silvana Munzi
Keyword(s):  
Global Change ◽  
Solar Radiation ◽  
Functional Groups ◽  
Physiological Response ◽  
Functional Group ◽  
Environmental Drivers ◽  
Combined Effects ◽  
Environmental Stressor ◽  
Comprehensive Understanding ◽  
Direct Sunlight

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.

scholarly journals Reduced resilience of terrestrial ecosystems locally is not reflected on a global scale

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Yuhao Feng ◽  
Haojie Su ◽  
Zhiyao Tang ◽  
Shaopeng Wang ◽  
Xia Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Vegetation Index ◽  
Global Climate ◽  
Terrestrial Ecosystem ◽  
Terrestrial Ecosystems ◽  
Global Scale ◽  
Ecological Resilience ◽  
Terrestrial Vegetation ◽  
Ecosystem Resilience

AbstractGlobal climate change likely alters the structure and function of vegetation and the stability of terrestrial ecosystems. It is therefore important to assess the factors controlling ecosystem resilience from local to global scales. Here we assess terrestrial vegetation resilience over the past 35 years using early warning indicators calculated from normalized difference vegetation index data. On a local scale we find that climate change reduced the resilience of ecosystems in 64.5% of the global terrestrial vegetated area. Temperature had a greater influence on vegetation resilience than precipitation, while climate mean state had a greater influence than climate variability. However, there is no evidence for decreased ecological resilience on larger scales. Instead, climate warming increased spatial asynchrony of vegetation which buffered the global-scale impacts on resilience. We suggest that the response of terrestrial ecosystem resilience to global climate change is scale-dependent and influenced by spatial asynchrony on the global scale.

scholarly journals Global phosphorus dynamics in terms of phosphine

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Wanyi Fu ◽  
Xihui Zhang
Keyword(s):  
Wastewater Treatment ◽  
Human Activities ◽  
Wastewater Treatment Plants ◽  
Global Climate ◽  
Global Scale ◽  
Phosphorus Cycle ◽  
Natural Ecosystems ◽  
Driving Cycles ◽  
Global Cycles ◽  
Urban Wastewater Treatment

AbstractSince the detection of phosphine in the wastewater treatment plants in 1988, more and more investigations revealed that phosphine is closely related to ecological activities on a global scale. Here, we present perspectives on the whole dynamic cycles of phosphorus, particularly in terms of phosphine and its interactions with natural ecosystems, as well as the impacts from human activities. It may conclude that the phosphine-driving cycles of phosphorus depend on the coordination of human activities with natural ecosystems. Most importantly, the extensive recovery of phosphorus in numerous urban wastewater treatment plants may seriously obstruct its global cycles to catch up with the ecological needs in natural ecosystems. Phosphine gas plays an important role in the biogeochemical phosphorus cycle. Phosphorus might be one of the important elements participating in the global climate change together with carbon and nitrogen.

Diatoms in Saline Lakes Paleoclimate and Paleoecology Interpretations

2007 ◽  
Vol 13 ◽  
pp. 149-168 ◽  
Author(s):  
Erik J. Ekdahl
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Global Climate Change ◽  
Water Conservation ◽  
Environmental Changes ◽  
Global Climate ◽  
Light Availability ◽  
Ionic Concentration ◽  
Mitigation Strategies ◽  
Environmental Response

Average global temperatures are predicted to rise over the next century and changes in precipitation, humidity, and drought frequency will likely accompany this global warming. Understanding associated changes in continental precipitation and temperature patterns in response to global change is an important component of long-range environmental planning. For example, agricultural management plans that account for decreased precipitation over time will be less susceptible to the effects of drought through implementation of water conservation techniques.A detailed understanding of environmental response to past climate change is key to understanding environmental changes associated with global climate change. To this end, diatoms are sensitive to a variety of limnologic parameters, including nutrient concentration, light availability, and the ionic concentration and composition of the waters that they live in (e.g. salinity). Diatoms from numerous environments have been used to reconstruct paleosalinity levels, which in turn have been used as a proxy records for regional and local paleoprecipitation. Long-term records of salinity or paleoprecipitation are valuable in reconstructing Quaternary paleoclimate, and are important in terms of developing mitigation strategies for future global climate change. High-resolution paleoclimate records are also important in groundtruthing global climate simulations, especially in regions where the consequences of global warming may be severe.

First comparison of quantitative estimates of termite biomass and abundance reveals strong intercontinental differences

2014 ◽  
Vol 30 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Cecilia A.L. Dahlsjö ◽  
Catherine L. Parr ◽  
Yadvinder Malhi ◽  
Homathevi Rahman ◽  
Patrick Meir ◽  
...  
Keyword(s):  
Functional Groups ◽  
Functional Diversity ◽  
Ecosystem Processes ◽  
Global Scale ◽  
Species Density ◽  
Abundance Data ◽  
Standardized Protocol ◽  
Biogeographical Distribution ◽  
Belt Transect

Abstract:Termite species and functional groups differ among regions globally (the functional-diversity anomaly). Here we investigate whether similar differences in biomass and abundance of termites occur among continents. Biomass and abundance data were collected with standardized sampling in Cameroon, Malaysia and Peru. Data from Peru were original to this study, while data from Cameroon and Malaysia were compiled from other sources. Species density data were sampled using a standardized belt transect (100 × 2 m) while the biomass and abundance measurements were sampled using a standardized protocol based on 2 × 2-m quadrats. Biomass and abundance data confirmed patterns found for species density and thus the existence of the functional diversity anomaly: highest estimates for biomass and abundance were found in Cameroon (14.5 ± 7.90 g m−2 and 1234 ± 437 ind m−2) followed by Malaysia (0.719 ± 0.193 g m−2 and 327 ± 72 ind m−2) and then Peru (0.345 ± 0.103 g m−2 and 130 ± 39 ind m−2). The biomass and abundance for each functional group were significantly different across sites for most termite functional groups. Biogeographical distribution of lineages was the primary cause for the functional diversity anomaly with true soil-feeding termites dominating in Cameroon and the absence of fungus-growing termites from Peru. These findings are important as the biomass and abundance of functional groups may be linked to ecosystem processes. Although this study allowed for comparisons between data from different regions further comparable data are needed to enhance the understanding of the role of termites in ecosystem processes on a global scale.

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