scholarly journals The up-scaling of ecosystem functions in a heterogeneous world

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Andrew M. Lohrer ◽  
Simon F. Thrush ◽  
Judi E. Hewitt ◽  
Casper Kraan
Keyword(s):  
Primary Productivity ◽  
Ecosystem Functioning ◽  
Large Scale ◽  
Net Primary Productivity ◽  
Marine Ecosystem ◽  
Ecosystem Functions ◽  
Small Scale ◽  
Biodiversity Crisis ◽  
Positive Effects ◽  
Marine Habitats

Abstract Earth is in the midst of a biodiversity crisis that is impacting the functioning of ecosystems and the delivery of valued goods and services. However, the implications of large scale species losses are often inferred from small scale ecosystem functioning experiments with little knowledge of how the dominant drivers of functioning shift across scales. Here, by integrating observational and manipulative experimental field data, we reveal scale-dependent influences on primary productivity in shallow marine habitats, thus demonstrating the scalability of complex ecological relationships contributing to coastal marine ecosystem functioning. Positive effects of key consumers (burrowing urchins, Echinocardium cordatum) on seafloor net primary productivity (NPP) elucidated by short-term, single-site experiments persisted across multiple sites and years. Additional experimentation illustrated how these effects amplified over time, resulting in greater primary producer biomass (sediment chlorophyll a content) in the longer term, depending on climatic context and habitat factors affecting the strengths of mutually reinforcing feedbacks. The remarkable coherence of results from small and large scales is evidence of real-world ecosystem function scalability and ecological self-organisation. This discovery provides greater insights into the range of responses to broad-scale anthropogenic stressors in naturally heterogeneous environmental settings.

scholarly journals Biodiversity promotes primary productivity and growing season lengthening at the landscape scale

2017 ◽  
Vol 114 (38) ◽  
pp. 10160-10165 ◽  
Author(s):  
Jacqueline Oehri ◽  
Bernhard Schmid ◽  
Gabriela Schaepman-Strub ◽  
Pascal A. Niklaus
Keyword(s):  
Primary Productivity ◽  
Ecosystem Functioning ◽  
Large Scale ◽  
Vascular Plant ◽  
Growing Season ◽  
Landscape Scale ◽  
Species Pool ◽  
Small Scale ◽  
Large Species ◽  
Growing Season Length

Experiments have shown positive biodiversity-ecosystem functioning (BEF) relationships in small plots with model communities established from species pools typically comprising few dozen species. Whether patterns found can be extrapolated to complex, nonexperimental, real-world landscapes that provide ecosystem services to humans remains unclear. Here, we combine species inventories from a large-scale network of 447 1-km2plots with remotely sensed indices of primary productivity (years 2000–2015). We show that landscape-scale productivity and its temporal stability increase with the diversity of plants and other taxa. Effects of biodiversity indicators on productivity were comparable in size to effects of other important drivers related to climate, topography, and land cover. These effects occurred in plots that integrated different ecosystem types (i.e., metaecosystems) and were consistent over vast environmental and altitudinal gradients. The BEF relations we report are as strong or even exceed the ones found in small-scale experiments, despite different community assembly processes and a species pool comprising nearly 2,000 vascular plant species. Growing season length increased progressively over the observation period, and this shift was accelerated in more diverse plots, suggesting that a large species pool is important for adaption to climate change. Our study further implies that abiotic global-change drivers may mediate ecosystem functioning through biodiversity changes.

Community Replacement Pathways: What Do Fossil Sequences Reveal About Marine Ecosystem Transitions?

1990 ◽  
Vol 5 ◽  
pp. 262-272
Author(s):  
William Miller
Keyword(s):  
Fossil Record ◽  
Large Scale ◽  
Marine Ecosystem ◽  
Small Scale ◽  
Data Sets ◽  
Mass Extinctions ◽  
Ultimate Cause ◽  
Long Time ◽  
History Of ◽  
Time And Energy

Paleontologists have lavished much time and energy on description and explanation of large-scale patterns in the fossil record (e.g., mass extinctions, histories of monophyletic taxa, deployment of major biogeographic units), while paying comparatively little attention to biologic patterns preserved only in local stratigraphic sequences. Interpretation of the large-scale patterns will always be seen as the chief justification for the science of paleontology, but solving problems framed by long time spans and large areas is rife with tenuous inference and patterns are prone to varied interpretation by different investigators using virtually the same data sets (as in the controversy over ultimate cause of the terminal Cretaceous extinctions). In other words, the large-scale patterns in the history of life are the true philosophical property of paleontology, but there will always be serious problems in attempting to resolve processes that transpired over millions to hundreds-of-millions of years and encompassed vast areas of seafloor or landscape. By contrast, less spectacular and more commonplace changes in local habitats (often related to larger-scale events and cycles) and attendant biologic responses are closer to our direct experience of the living world and should be easier to interpret unequivocally. These small-scale responses are reflected in the fossil record at the scale of local outcrops.

scholarly journals More individuals but fewer species: testing the ‘more individuals hypothesis’ in a diverse tropical fauna

2010 ◽  
Vol 6 (4) ◽  
pp. 490-493 ◽  
Author(s):  
Terrence P. McGlynn ◽  
Michael D. Weiser ◽  
Robert R. Dunn
Keyword(s):  
Species Richness ◽  
Primary Productivity ◽  
Large Scale ◽  
Positive Relationship ◽  
Tropical Rainforest ◽  
Net Primary Productivity ◽  
Resource Abundance ◽  
Monotonic Increase ◽  
Ant Diversity ◽  
Unimodal Relationship

A positive relationship between species richness and productivity is often observed in nature, but the causes remain contentious. One mechanism, the ‘more individuals hypothesis’ (MIH), predicts richness increases monotonically with density, as a function of resource flux. To test the MIH, we manipulated resource abundance in a community of tropical rainforest litter ants and measured richness and density responses. A unimodal relationship between richness and density most closely fitted the control and disturbance (resource removal) treatments in contrast to expectations of the MIH. Resource addition resulted in a monotonic increase in richness relative to density, a shift from the pattern in the control. In the disturbance treatment, richness was greater than in the control, opposite to expectations of the MIH. While large-scale correlations between ant diversity and net primary productivity or temperature are reconcilable with the MIH, key elements of the hypothesis are not supported.

scholarly journals Comprehensive Assessment of the Effect of Urban Built-Up Land Expansion and Climate Change on Net Primary Productivity

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Pengyan Zhang ◽  
Yanyan Li ◽  
Wenlong Jing ◽  
Dan Yang ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Urban Expansion ◽  
Ecosystem Functions ◽  
Rapid Urbanization ◽  
Important Indicator ◽  
The Impact

Urbanization is causing profound changes in ecosystem functions at local and regional scales. The net primary productivity (NPP) is an important indicator of global change, rapid urbanization and climate change will have a significant impact on NPP, and urban expansion and climate change in different regions have different impacts on NPP, especially in densely populated areas. However, to date, efforts to quantify urban expansion and climate change have been limited, and the impact of long-term continuous changes in NPP has not been well understood. Based on land use data, night light data, NPP data, climate data, and a series of social and economic data, we performed a comprehensive analysis of land use change in terms of type and intensity and explored the pattern of urban expansion and its relationship with NPP and climate change for the period of 2000–2015, taking Zhengzhou, China, as an example. The results show that the major form of land use change was cropland to built-up land during the 2000–2015 period, with a total area of 367.51 km2 converted. The NPP exhibited a generally increasing trend in the study area except for built-up land and water area. The average correlation coefficients between temperature and NPP and precipitation and NPP were 0.267 and 0.020, respectively, indicating that an increase in temperature and precipitation can promote NPP despite significant spatial differences. During the examined period, most expansion areas exhibited an increasing NPP trend, indicating that the influence of urban expansion on NPP is mainly characterized by an evident influence of the expansion area. The study can provide a reference for Zhengzhou and even the world's practical research to improve land use efficiency, increase agricultural productivity and natural carbon sinks, and maintain low-carbon development.

Small scale transport processes from HF-Radar

2020 ◽  
Author(s):  
Ismael Hernández-Carrasco ◽  
Alejandro Orfila ◽  
Vincent Rossi ◽  
Veronique Garçon
Keyword(s):  
Large Scale ◽  
Marine Ecosystem ◽  
Transport Processes ◽  
Hf Radar ◽  
Small Scale ◽  
Biological Productivity ◽  
Physical Mechanisms ◽  
Flow Geometry ◽  
Physical Interactions ◽  
Global Biogeochemical Cycles

<p>Coastal ocean ecosystems are major contributor to the global biogeochemical cycles and biological productivity. Physical<br>factors induced by the turbulent flow play a crucial role in regulating marine ecosystem. However, while large scale dynamics<br>in the open ocean is well described by geostrophy, the role of small scale transport processes in coastal regions is still<br>poorly understood due to lack of continuous high-resolution observations. Here, the influence of small-scale coastal dynamics<br>on surface phytoplankton structuring is studied using Lagrangian metrics computed from HF Radar currents and satellite<br>chlorophyll-a (Chl). The combination of complementary Lagrangian diagnostics, including the accumulated divergence of the<br>flow along fluid trajectories, provides an improved description of the 3D flow geometry which facilitates the interpretation of two<br>non-exclusive physical mechanisms affecting phytoplankton patchiness. Attracting submesoscale fronts, unveiled by backwards<br>Lagrangian Coherent Structures, are associated to negative Lagrangian divergence where particles and Chl standing stocks<br>cluster. Filaments of positive Lagrangian divergence, representing large accumulated upward vertical velocities and suggesting<br>accrued injection of subsurface nutrients, match areas with large Chl concentrations. Our findings demonstrate that an accurate<br>description of small-scale transport processes is necessary to comprehend bio-physical interactions in coastal seas and to<br>estimate biological productivity.</p>

scholarly journals Asymmetric responses of primary productivity to altered precipitation simulated by ecosystem models across three long-term grassland sites

2018 ◽  
Vol 15 (11) ◽  
pp. 3421-3437 ◽  
Author(s):  
Donghai Wu ◽  
Philippe Ciais ◽  
Nicolas Viovy ◽  
Alan K. Knapp ◽  
Kevin Wilcox ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Precipitation Variability ◽  
Aboveground Net Primary Productivity ◽  
Ecosystem Models ◽  
Rainfall Gradient ◽  
Positive Effects ◽  
Altered Precipitation ◽  
The Mean ◽  
Asymmetric Responses

Abstract. Field measurements of aboveground net primary productivity (ANPP) in temperate grasslands suggest that both positive and negative asymmetric responses to changes in precipitation (P) may occur. Under normal range of precipitation variability, wet years typically result in ANPP gains being larger than ANPP declines in dry years (positive asymmetry), whereas increases in ANPP are lower in magnitude in extreme wet years compared to reductions during extreme drought (negative asymmetry). Whether the current generation of ecosystem models with a coupled carbon–water system in grasslands are capable of simulating these asymmetric ANPP responses is an unresolved question. In this study, we evaluated the simulated responses of temperate grassland primary productivity to scenarios of altered precipitation with 14 ecosystem models at three sites: Shortgrass steppe (SGS), Konza Prairie (KNZ) and Stubai Valley meadow (STU), spanning a rainfall gradient from dry to moist. We found that (1) the spatial slopes derived from modeled primary productivity and precipitation across sites were steeper than the temporal slopes obtained from inter-annual variations, which was consistent with empirical data; (2) the asymmetry of the responses of modeled primary productivity under normal inter-annual precipitation variability differed among models, and the mean of the model ensemble suggested a negative asymmetry across the three sites, which was contrary to empirical evidence based on filed observations; (3) the mean sensitivity of modeled productivity to rainfall suggested greater negative response with reduced precipitation than positive response to an increased precipitation under extreme conditions at the three sites; and (4) gross primary productivity (GPP), net primary productivity (NPP), aboveground NPP (ANPP) and belowground NPP (BNPP) all showed concave-down nonlinear responses to altered precipitation in all the models, but with different curvatures and mean values. Our results indicated that most models overestimate the negative drought effects and/or underestimate the positive effects of increased precipitation on primary productivity under normal climate conditions, highlighting the need for improving eco-hydrological processes in those models in the future.

scholarly journals Characteristics of aquatic biospheres on temperate planets around Sun-like stars and M dwarfs

2021 ◽  
Vol 503 (3) ◽  
pp. 3434-3448
Author(s):  
Manasvi Lingam ◽  
Abraham Loeb
Keyword(s):  
Primary Productivity ◽  
Large Scale ◽  
Carbon Fixation ◽  
Net Primary Productivity ◽  
Effective Rate ◽  
Environmental Variable ◽  
Oxygenic Photosynthesis ◽  
M Dwarfs ◽  
Earth Like Planets ◽  
Rocky Planets

ABSTRACT Aquatic biospheres reliant on oxygenic photosynthesis are expected to play an important role on Earth-like planets endowed with large-scale oceans insofar as carbon fixation (i.e. biosynthesis of organic compounds) is concerned. We investigate the properties of aquatic biospheres comprising Earth-like biota for habitable rocky planets orbiting Sun-like stars and late-type M dwarfs such as TRAPPIST-1. In particular, we estimate how these characteristics evolve with the available flux of photosynthetically active radiation (PAR) and the ambient ocean temperature (TW), the latter of which constitutes a key environmental variable. We show that many salient properties, such as the depth of the photosynthesis zone and the net primary productivity (i.e. the effective rate of carbon fixation), are sensitive to PAR flux and TW and decline substantially when the former is decreased or the latter is increased. We conclude by exploring the implications of our analysis for exoplanets around Sun-like stars and M dwarfs.

scholarly journals Description and Validation of the Simple, Efficient, Dynamic, Global, Ecological Simulator (SEDGES v.1.0)

2017 ◽  
Author(s):  
Pablo Paiewonsky ◽  
Oliver Elison Timm
Keyword(s):  
Primary Productivity ◽  
Land Surface ◽  
Large Scale ◽  
Net Primary Productivity ◽  
Climate Model ◽  
Hydrological Cycle ◽  
Bare Soil ◽  
Relative Advantage ◽  
Coupling Scheme ◽  
Area Index

Abstract. In this paper, we present a simple vegetation model whose primary intended use is auxiliary to the land-atmosphere coupling scheme of a climate model, particularly one of intermediate complexity. The model formulations and their derivations are presented here, in detail. The model includes some realistic and useful features for its level of complexity, including a photosynthetic dependency on light, full coupling of photosynthesis and transpiration through an interactive canopy resistance, and a soil organic carbon dependence for bare soil albedo. We evaluate the model's performance by running it using a simple land surface scheme that is driven by reanalysis data. The evaluation against observational data includes net primary productivity, leaf area index, surface albedo, and diagnosed variables relevant for the closure of the hydrological cycle. In this set up, we find that the model gives an adequate to good simulation of basic large-scale ecological and hydrological variables. Of the variables analyzed in this paper, gross primary productivity is particularly well simulated. The results also reveal the current limitations of the model. The most significant deficiency is the excessive simulation of evapotranspiration in mid- to high northern latitudes during their winter to spring transition. The model has relative advantage in situations that require some combination of computational efficiency, model transparency and tractability, and the simulation of the large scale vegetation and land surface characteristics under non-present day conditions.

scholarly journals The assessment of a global marine ecosystem model on the basis of emergent properties and ecosystem function: a case study with ERSEM

2016 ◽  
Vol 9 (1) ◽  
pp. 59-76 ◽  
Author(s):  
L. de Mora ◽  
M. Butenschön ◽  
J. I. Allen
Keyword(s):  
Ecosystem Function ◽  
Large Scale ◽  
Marine Ecosystem ◽  
Ecosystem Model ◽  
Ecosystem Functions ◽  
Emergent Properties ◽  
Quantitative Metrics ◽  
Marine Ecosystem Model ◽  
Scale Properties ◽  
Meta Analyses

Abstract. Ecosystem models are often assessed using quantitative metrics of absolute ecosystem state, but these model–data comparisons are disproportionately vulnerable to discrepancies in the location of important circulation features. An alternative method is to demonstrate the models capacity to represent ecosystem function; the emergence of a coherent natural relationship in a simulation indicates that the model may have an appropriate representation of the ecosystem functions that lead to the emergent relationship. Furthermore, as emergent properties are large-scale properties of the system, model validation with emergent properties is possible even when there is very little or no appropriate data for the region under study, or when the hydrodynamic component of the model differs significantly from that observed in nature at the same location and time.A selection of published meta-analyses are used to establish the validity of a complex marine ecosystem model and to demonstrate the power of validation with emergent properties. These relationships include the phytoplankton community structure, the ratio of carbon to chlorophyll in phytoplankton and particulate organic matter, the ratio of particulate organic carbon to particulate organic nitrogen and the stoichiometric balance of the ecosystem.These metrics can also inform aspects of the marine ecosystem model not available from traditional quantitative and qualitative methods. For instance, these emergent properties can be used to validate the design decisions of the model, such as the range of phytoplankton functional types and their behaviour, the stoichiometric flexibility with regards to each nutrient, and the choice of fixed or variable carbon to nitrogen ratios.

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