Synergistic impacts of habitat loss and fragmentation on model ecosystems

Habitat loss and fragmentation are major threats to biodiversity, yet separating their effects is challenging. We use a multi-trophic, trait-based, and spatially explicit general ecosystem model to examine the independent and synergistic effects of these processes on ecosystem structure. We manipulated habitat by removing plant biomass in varying spatial extents, intensities, and configurations. We found that emergent synergistic interactions of loss and fragmentation are major determinants of ecosystem response, including population declines and trophic pyramid shifts. Furthermore, trait-mediated interactions, such as a disproportionate sensitivity of large-sized organisms to fragmentation, produce significant effects in shaping responses. We also show that top-down regulation mitigates the effects of land use on plant biomass loss, suggesting that models lacking these interactions—including most carbon stock models—may not adequately capture land-use change impacts. Our results have important implications for understanding ecosystem responses to environmental change, and assessing the impacts of habitat fragmentation.

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Synergistic effects of climate and land‐use change influence broad‐scale avian population declines

Global Change Biology ◽

10.1111/gcb.14571 ◽

2019 ◽

Vol 25 (5) ◽

pp. 1561-1575 ◽

Cited By ~ 17

Author(s):

Joseph M. Northrup ◽

James W. Rivers ◽

Zhiqiang Yang ◽

Matthew G. Betts

Keyword(s):

Land Use ◽

Land Use Change ◽

Synergistic Effects ◽

Population Declines ◽

Broad Scale

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Potential extinction debt due to habitat loss and fragmentation in subalpine moorland ecosystems

Plant Ecology ◽

10.1007/s11258-021-01118-4 ◽

2021 ◽

Author(s):

Daichi Makishima ◽

Rui Sutou ◽

Akihito Goto ◽

Yutaka Kawai ◽

Naohiro Ishii ◽

...

Keyword(s):

Habitat Loss ◽

Extinction Debt ◽

Habitat Loss And Fragmentation

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The effects of modern war and military activities on biodiversity and the environment

Environmental Reviews ◽

10.1139/er-2015-0039 ◽

2015 ◽

Vol 23 (4) ◽

pp. 443-460 ◽

Cited By ~ 46

Author(s):

Michael J. Lawrence ◽

Holly L.J. Stemberger ◽

Aaron J. Zolderdo ◽

Daniel P. Struthers ◽

Steven J. Cooke

Keyword(s):

Military Training ◽

Structure And Function ◽

Aquatic Systems ◽

Ecosystem Structure ◽

Population Declines ◽

Exclusion Zone ◽

Negative Effects ◽

And Function ◽

Ecosystem Structure And Function ◽

Modern War

War is an ever-present force that has the potential to alter the biosphere. Here we review the potential consequences of modern war and military activities on ecosystem structure and function. We focus on the effects of direct conflict, nuclear weapons, military training, and military produced contaminants. Overall, the aforementioned activities were found to have overwhelmingly negative effects on ecosystem structure and function. Dramatic habitat alteration, environmental pollution, and disturbance contributed to population declines and biodiversity losses arising from both acute and chronic effects in both terrestrial and aquatic systems. In some instances, even in the face of massive alterations to ecosystem structure, recovery was possible. Interestingly, military activity was beneficial under specific conditions, such as when an exclusion zone was generated that generally resulted in population increases and (or) population recovery; an observation noted in both terrestrial and aquatic systems. Additionally, military technological advances (e.g., GPS technology, drone technology, biotelemetry) have provided conservation scientists with novel tools for research. Because of the challenges associated with conducting research in areas with military activities (e.g., restricted access, hazardous conditions), information pertaining to military impacts on the environment are relatively scarce and are often studied years after military activities have ceased and with no knowledge of baseline conditions. Additional research would help to elucidate the environmental consequences (positive and negative) and thus reveal opportunities for mitigating negative effects while informing the development of optimal strategies for rehabilitation and recovery.

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Integrated ecosystem model for simulating land use allocation

Ecological Modelling ◽

10.1016/j.ecolmodel.2011.12.009 ◽

2012 ◽

Vol 227 ◽

pp. 46-55 ◽

Cited By ~ 19

Author(s):

Szu-Hua Wang ◽

Shu-Li Huang ◽

William W. Budd

Keyword(s):

Land Use ◽

Ecosystem Model ◽

Land Use Allocation

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Consequences of habitat loss and fragmentation for wetland amphibian assemblages

Wetlands ◽

10.1007/bf03161728 ◽

1999 ◽

Vol 19 (1) ◽

pp. 1-12 ◽

Cited By ~ 169

Author(s):

Richard M. Lehtinen ◽

Susan M. Galatowitsch ◽

John R. Tester

Keyword(s):

Habitat Loss ◽

Habitat Loss And Fragmentation

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Assessing Mammal Species Losses Due to Habitat Loss and Fragmentation Across the World's Terrestrial Ecoregions

SSRN Electronic Journal ◽

10.2139/ssrn.3796529 ◽

2021 ◽

Author(s):

Koen Jacobus Josefus Kuipers ◽

Jelle P. Hilbers ◽

John Garcia-Ulloa ◽

Bente J. Graae ◽

Roel May ◽

...

Keyword(s):

Habitat Loss ◽

Mammal Species ◽

Habitat Loss And Fragmentation

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Carbon budget estimation of a subarctic catchment using a dynamic ecosystem model at high spatial resolution

Biogeosciences ◽

10.5194/bg-12-2791-2015 ◽

2015 ◽

Vol 12 (9) ◽

pp. 2791-2808 ◽

Cited By ~ 9

Author(s):

J. Tang ◽

P. A. Miller ◽

A. Persson ◽

D. Olefeldt ◽

P. Pilesjö ◽

...

Keyword(s):

Spatial Resolution ◽

Carbon Budget ◽

High Spatial Resolution ◽

Carbon Sink ◽

Carbon Fluxes ◽

Ecosystem Model ◽

Carbon Exchange ◽

Arctic Ecosystems ◽

Flux Dynamics ◽

Ecosystem Responses

Abstract. A large amount of organic carbon is stored in high-latitude soils. A substantial proportion of this carbon stock is vulnerable and may decompose rapidly due to temperature increases that are already greater than the global average. It is therefore crucial to quantify and understand carbon exchange between the atmosphere and subarctic/arctic ecosystems. In this paper, we combine an Arctic-enabled version of the process-based dynamic ecosystem model, LPJ-GUESS (version LPJG-WHyMe-TFM) with comprehensive observations of terrestrial and aquatic carbon fluxes to simulate long-term carbon exchange in a subarctic catchment at 50 m resolution. Integrating the observed carbon fluxes from aquatic systems with the modeled terrestrial carbon fluxes across the whole catchment, we estimate that the area is a carbon sink at present and will become an even stronger carbon sink by 2080, which is mainly a result of a projected densification of birch forest and its encroachment into tundra heath. However, the magnitudes of the modeled sinks are very dependent on future atmospheric CO2 concentrations. Furthermore, comparisons of global warming potentials between two simulations with and without CO2 increase since 1960 reveal that the increased methane emission from the peatland could double the warming effects of the whole catchment by 2080 in the absence of CO2 fertilization of the vegetation. This is the first process-based model study of the temporal evolution of a catchment-level carbon budget at high spatial resolution, including both terrestrial and aquatic carbon. Though this study also highlights some limitations in modeling subarctic ecosystem responses to climate change, such as aquatic system flux dynamics, nutrient limitation, herbivory and other disturbances, and peatland expansion, our study provides one process-based approach to resolve the complexity of carbon cycling in subarctic ecosystems while simultaneously pointing out the key model developments for capturing complex subarctic processes.

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Ecosystem responses to elevated CO<sub>2</sub> using airborne remote sensing at Mammoth Mountain, California

Biogeosciences ◽

10.5194/bg-15-7403-2018 ◽

2018 ◽

Vol 15 (24) ◽

pp. 7403-7418 ◽

Cited By ~ 3

Author(s):

Kerry Cawse-Nicholson ◽

Joshua B. Fisher ◽

Caroline A. Famiglietti ◽

Amy Braverman ◽

Florian M. Schwandner ◽

...

Keyword(s):

Remote Sensing ◽

Co2 Emissions ◽

Elevated Co2 ◽

Co2 Flux ◽

Ecosystem Structure ◽

Soil Co2 ◽

Ecosystem Responses ◽

Mammoth Mountain ◽

And Function ◽

Canopy Nitrogen

Abstract. We present an exploratory study examining the use of airborne remote-sensing observations to detect ecological responses to elevated CO2 emissions from active volcanic systems. To evaluate these ecosystem responses, existing spectroscopic, thermal, and lidar data acquired over forest ecosystems on Mammoth Mountain volcano, California, were exploited, along with in situ measurements of persistent volcanic soil CO2 fluxes. The elevated CO2 response was used to statistically model ecosystem structure, composition, and function, evaluated via data products including biomass, plant foliar traits and vegetation indices, and evapotranspiration (ET). Using regression ensemble models, we found that soil CO2 flux was a significant predictor for ecological variables, including canopy greenness (normalized vegetation difference index, NDVI), canopy nitrogen, ET, and biomass. With increasing CO2, we found a decrease in ET and an increase in canopy nitrogen, both consistent with theory, suggesting more water- and nutrient-use-efficient canopies. However, we also observed a decrease in NDVI with increasing CO2 (a mean NDVI of 0.27 at 200 g m−2 d−1 CO2 reduced to a mean NDVI of 0.10 at 800 g m−2 d−1 CO2). This is inconsistent with theory though consistent with increased efficiency of fewer leaves. We found a decrease in above-ground biomass with increasing CO2, also inconsistent with theory, but we did also find a decrease in biomass variance, pointing to a long-term homogenization of structure with elevated CO2. Additionally, the relationships between ecological variables changed with elevated CO2, suggesting a shift in coupling/decoupling among ecosystem structure, composition, and function synergies. For example, ET and biomass were significantly correlated for areas without elevated CO2 flux but decoupled with elevated CO2 flux. This study demonstrates that (a) volcanic systems show great potential as a means to study the properties of ecosystems and their responses to elevated CO2 emissions and (b) these ecosystem responses are measurable using a suite of airborne remotely sensed data.

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Land Use Increases the Correlation between Tree Cover and Biomass Carbon Stocks in the Global Tropics

Land ◽

10.3390/land10111217 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1217

Author(s):

Manan Bhan ◽

Simone Gingrich ◽

Sarah Matej ◽

Steffen Fritz ◽

Karl-Heinz Erb

Keyword(s):

Land Use ◽

Land Cover ◽

Land Cover Change ◽

Land Management ◽

Empirical Relationship ◽

Carbon Stocks ◽

Tree Cover ◽

Ecosystem Structure ◽

Biomass Carbon ◽

Potential Vegetation

Tree cover (TC) and biomass carbon stocks (CS) are key parameters for characterizing vegetation and are indispensable for assessing the role of terrestrial ecosystems in the global climate system. Land use, through land cover change and land management, affects both parameters. In this study, we quantify the empirical relationship between TC and CS and demonstrate the impacts of land use by combining spatially explicit estimates of TC and CS in actual and potential vegetation (i.e., in the hypothetical absence of land use) across the global tropics (~23.4° N to 23.4° S). We find that land use strongly alters both TC and CS, with stronger effects on CS than on TC across tropical biomes, especially in tropical moist forests. In comparison to the TC-CS correlation observed in the potential vegetation (biome-level R based on tropical ecozones = 0.56–0.90), land use strongly increases this correlation (biome-level R based on tropical ecozones = 0.87–0.94) in the actual vegetation. Increased correlations are not only the effects of land cover change. We additionally identify land management impacts in closed forests, which cause CS reductions. Our large-scale assessment of the TC-CS relationship can inform upcoming remote sensing efforts to map ecosystem structure in high spatio-temporal detail and highlights the need for an explicit focus on land management impacts in the tropics.

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