Pub Date : 2024-01-25DOI: 10.1007/s10021-024-00900-5
Roi Ankori-Karlinsky, Jazlynn Hall, Lora Murphy, Robert Muscarella, Sebastián Martinuzzi, Robert Fahey, Jess K. Zimmerman, María Uriarte
Tropical forests are the world’s most structurally complex ecosystems, providing key functions like biomass accumulation, which is linked to this complexity. Tropical forests are also exposed to chronic, non-severe winds, yet their effect on forest structural complexity is understudied. Here we examine drivers of forest structural complexity in Puerto Rico with a particular focus on chronic wind exposure. We used airborne light detection and ranging data collected in 2016 to quantify canopy height and rugosity (variation in height) in ~ 20,000, 0.28 ha forested sites stratified by forest age. We used random forest models to analyze variation in canopy height and rugosity as a function of chronic wind exposure, forest age, mean annual precipitation, elevation, slope (in degrees), soil type, soil available water storage, and exposure to a previous hurricane. Canopy height was driven by precipitation, forest age, and chronic wind exposure, decreasing by 2.12 m (16%) on average in wind-exposed forests across all forest ages. Canopy height increased by 4.0 m (41%) on average in forests aged 25–66 years, and by 4.0 m between sites with 1000 and 2000 mm y−1 precipitation. Canopy rugosity was driven by canopy height, precipitation, forest age, and elevation, increasing log-linearly with canopy height and precipitation, decreasing with elevation, and was highest in younger forests. Chronic wind exposure did not drive variation in canopy rugosity. Our results suggest that chronic wind exposure plays an integral role in limiting canopy height, potentially reducing aboveground carbon accumulation in older tropical forests.
{"title":"Chronic Winds Reduce Tropical Forest Structural Complexity Regardless of Climate, Topography, or Forest Age","authors":"Roi Ankori-Karlinsky, Jazlynn Hall, Lora Murphy, Robert Muscarella, Sebastián Martinuzzi, Robert Fahey, Jess K. Zimmerman, María Uriarte","doi":"10.1007/s10021-024-00900-5","DOIUrl":"https://doi.org/10.1007/s10021-024-00900-5","url":null,"abstract":"<p>Tropical forests are the world’s most structurally complex ecosystems, providing key functions like biomass accumulation, which is linked to this complexity. Tropical forests are also exposed to chronic, non-severe winds, yet their effect on forest structural complexity is understudied. Here we examine drivers of forest structural complexity in Puerto Rico with a particular focus on chronic wind exposure. We used airborne light detection and ranging data collected in 2016 to quantify canopy height and rugosity (variation in height) in ~ 20,000, 0.28 ha forested sites stratified by forest age. We used random forest models to analyze variation in canopy height and rugosity as a function of chronic wind exposure, forest age, mean annual precipitation, elevation, slope (in degrees), soil type, soil available water storage, and exposure to a previous hurricane. Canopy height was driven by precipitation, forest age, and chronic wind exposure, decreasing by 2.12 m (16%) on average in wind-exposed forests across all forest ages. Canopy height increased by 4.0 m (41%) on average in forests aged 25–66 years, and by 4.0 m between sites with 1000 and 2000 mm y<sup>−1</sup> precipitation. Canopy rugosity was driven by canopy height, precipitation, forest age, and elevation, increasing log-linearly with canopy height and precipitation, decreasing with elevation, and was highest in younger forests. Chronic wind exposure did not drive variation in canopy rugosity. Our results suggest that chronic wind exposure plays an integral role in limiting canopy height, potentially reducing aboveground carbon accumulation in older tropical forests.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139584570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-22DOI: 10.1007/s10021-023-00886-6
Abstract
Quantifying uncertainty is important to establishing the significance of comparisons, to making predictions with known confidence, and to identifying priorities for investment. However, uncertainty can be difficult to quantify correctly. While sampling error is commonly reported based on replicate measurements, the uncertainty in regression models used to estimate forest biomass from tree dimensions is commonly ignored and has sometimes been reported incorrectly, due either to lack of clarity in recommended procedures or to incentives to underestimate uncertainties. Even more rarely are the uncertainty in predicting individuals and the uncertainty in the mean both recognized for their contributions to overall uncertainty. In this paper, we demonstrate the effect of propagating these two sources of uncertainty using a simple example of calcium concentration of sugar maple foliage, which does not require regression, then the mass of foliage and calcium content of foliage, and finally an entire forest with multiple species and tissue types. The uncertainty due to predicting individuals is greater than the uncertainty in the mean for studies with few trees—up to 30 trees for foliar calcium concentration and 50 trees for foliar mass and calcium content in the data set we analyzed from the Hubbard Brook Experimental Forest. The most correct analysis will take both sources of uncertainty into account, but for practical purposes, country-level reports of uncertainty in carbon stocks can safely ignore the uncertainty in individuals, which becomes negligible with large enough numbers of trees. Ignoring the uncertainty in the mean will result in exaggerated confidence in estimates of forest biomass and carbon and nutrient contents.
{"title":"Propagating Uncertainty in Predicting Individuals and Means Illustrated with Foliar Chemistry and Forest Biomass","authors":"","doi":"10.1007/s10021-023-00886-6","DOIUrl":"https://doi.org/10.1007/s10021-023-00886-6","url":null,"abstract":"<h3>Abstract</h3> <p>Quantifying uncertainty is important to establishing the significance of comparisons, to making predictions with known confidence, and to identifying priorities for investment. However, uncertainty can be difficult to quantify correctly. While sampling error is commonly reported based on replicate measurements, the uncertainty in regression models used to estimate forest biomass from tree dimensions is commonly ignored and has sometimes been reported incorrectly, due either to lack of clarity in recommended procedures or to incentives to underestimate uncertainties. Even more rarely are the uncertainty in predicting individuals and the uncertainty in the mean both recognized for their contributions to overall uncertainty. In this paper, we demonstrate the effect of propagating these two sources of uncertainty using a simple example of calcium concentration of sugar maple foliage, which does not require regression, then the mass of foliage and calcium content of foliage, and finally an entire forest with multiple species and tissue types. The uncertainty due to predicting individuals is greater than the uncertainty in the mean for studies with few trees—up to 30 trees for foliar calcium concentration and 50 trees for foliar mass and calcium content in the data set we analyzed from the Hubbard Brook Experimental Forest. The most correct analysis will take both sources of uncertainty into account, but for practical purposes, country-level reports of uncertainty in carbon stocks can safely ignore the uncertainty in individuals, which becomes negligible with large enough numbers of trees. Ignoring the uncertainty in the mean will result in exaggerated confidence in estimates of forest biomass and carbon and nutrient contents.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139517635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.1007/s10021-023-00895-5
Alicia M. Carhart, Deanne C. Drake, James R. Fischer, Jeffrey N. Houser, Kathi J. Jankowski, John E. Kalas, Eric M. Lund
Ecosystem processes in rivers are thought to be controlled more by extrinsic than intrinsic factors, that is, the result of processes that occur upstream or within their watersheds. However, large floodplain rivers have a diverse assemblage of aquatic areas spanning gradients of connectivity with the main channel and internal controls may at times regulate long-term dynamics. When and where internal controls are important has not been widely explored in rivers. The Upper Mississippi River System (UMRS) provides a unique opportunity to assess regulation of ecosystem processes in a large floodplain river as water clarity has increased in several reaches over the last two decades. To better understand when and where intrinsic variables (for example, aquatic vegetation and common carp) and extrinsic variables (for example, upstream main channel total suspended solids (TSS) concentration and discharge) regulate water clarity, we describe 24-year trends of TSS in six study reaches of the UMRS. We evaluated the degree to which trends were shared across aquatic areas within each study reach and identified potential drivers of long-term TSS dynamics. Results varied across and within UMRS reaches, but common carp abundance was the strongest predictor in nearly all study reaches. Several models indicated associations with both intrinsic and extrinsic factors, and the marginal model r2 values (0.26–0.61) suggest that additional environmental factors may have influenced water clarity. Knowledge of the degree to which intrinsic and extrinsic processes regulate water clarity is important for understanding and managing large, floodplain rivers worldwide.
{"title":"Intrinsic and Extrinsic Regulation of Water Clarity in a Large, Floodplain River Ecosystem","authors":"Alicia M. Carhart, Deanne C. Drake, James R. Fischer, Jeffrey N. Houser, Kathi J. Jankowski, John E. Kalas, Eric M. Lund","doi":"10.1007/s10021-023-00895-5","DOIUrl":"https://doi.org/10.1007/s10021-023-00895-5","url":null,"abstract":"<p>Ecosystem processes in rivers are thought to be controlled more by extrinsic than intrinsic factors, that is, the result of processes that occur upstream or within their watersheds. However, large floodplain rivers have a diverse assemblage of aquatic areas spanning gradients of connectivity with the main channel and internal controls may at times regulate long-term dynamics. When and where internal controls are important has not been widely explored in rivers. The Upper Mississippi River System (UMRS) provides a unique opportunity to assess regulation of ecosystem processes in a large floodplain river as water clarity has increased in several reaches over the last two decades. To better understand when and where intrinsic variables (for example<i>,</i> aquatic vegetation and common carp) and extrinsic variables (for example<i>,</i> upstream main channel total suspended solids (TSS) concentration and discharge) regulate water clarity, we describe 24-year trends of TSS in six study reaches of the UMRS. We evaluated the degree to which trends were shared across aquatic areas within each study reach and identified potential drivers of long-term TSS dynamics. Results varied across and within UMRS reaches, but common carp abundance was the strongest predictor in nearly all study reaches. Several models indicated associations with both intrinsic and extrinsic factors, and the marginal model <i>r</i><sup>2</sup> values (0.26–0.61) suggest that additional environmental factors may have influenced water clarity. Knowledge of the degree to which intrinsic and extrinsic processes regulate water clarity is important for understanding and managing large, floodplain rivers worldwide.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139498522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-18DOI: 10.1007/s10021-023-00896-4
Olivia L. Hajek, Matthew A. Sturchio, Alan K. Knapp
Understanding how cool-season C3 and warm-season C4 grasses will respond to climate change is critical for predicting future ecosystem functioning in many grasslands. With warming, C4 grasses are expected to increase relative to C3 grasses, but alterations in the seasonal availability of water may also influence C3/C4 dynamics because of their distinct seasons of growth. To better understand how shifts in the seasonal availability of water can affect ecosystem function in a northern mixed-grass prairie in southeastern Wyoming, we reduced early season rainfall (April–June) using rainout shelters and added the amount of excluded precipitation later in the growing season (July–September), effectively shifting spring rainfall to summer rainfall. As expected, this shift in precipitation seasonality altered patterns of soil water availability, leading to a 29% increase in soil respiration and sustained canopy greenness throughout the growing season. Despite these responses, there were no significant differences in C3 aboveground net primary production (ANPP) between the seasonally shifted treatment and the plots that received ambient precipitation, likely due to the high levels of spring soil moisture present before rainout shelters were deployed that sustained C3 grass growth. However, in plots with high C4 grass cover, C4 ANPP increased significantly in response to increased summer rainfall. Overall, we provide the first experimental evidence that shifts in the seasonality of precipitation, with no change in temperature, will differentially impact C3 versus C4 species, altering the dynamics of carbon cycling in this geographically extensive semi-arid grassland.
{"title":"Experimental Evidence Supporting the Seasonal Availability of Water Hypothesis in a Mixed C3/C4 Grassland","authors":"Olivia L. Hajek, Matthew A. Sturchio, Alan K. Knapp","doi":"10.1007/s10021-023-00896-4","DOIUrl":"https://doi.org/10.1007/s10021-023-00896-4","url":null,"abstract":"<p>Understanding how cool-season C<sub>3</sub> and warm-season C<sub>4</sub> grasses will respond to climate change is critical for predicting future ecosystem functioning in many grasslands. With warming, C<sub>4</sub> grasses are expected to increase relative to C<sub>3</sub> grasses, but alterations in the seasonal availability of water may also influence C<sub>3</sub>/C<sub>4</sub> dynamics because of their distinct seasons of growth. To better understand how shifts in the seasonal availability of water can affect ecosystem function in a northern mixed-grass prairie in southeastern Wyoming, we reduced early season rainfall (April–June) using rainout shelters and added the amount of excluded precipitation later in the growing season (July–September), effectively shifting spring rainfall to summer rainfall. As expected, this shift in precipitation seasonality altered patterns of soil water availability, leading to a 29% increase in soil respiration and sustained canopy greenness throughout the growing season. Despite these responses, there were no significant differences in C<sub>3</sub> aboveground net primary production (ANPP) between the seasonally shifted treatment and the plots that received ambient precipitation, likely due to the high levels of spring soil moisture present before rainout shelters were deployed that sustained C<sub>3</sub> grass growth. However, in plots with high C<sub>4</sub> grass cover, C<sub>4</sub> ANPP increased significantly in response to increased summer rainfall. Overall, we provide the first experimental evidence that shifts in the seasonality of precipitation, with no change in temperature, will differentially impact C<sub>3</sub> versus C<sub>4</sub> species, altering the dynamics of carbon cycling in this geographically extensive semi-arid grassland.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139498527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-16DOI: 10.1007/s10021-023-00892-8
Carling Bieg, Henri Vallès, Alexander Tewfik, Brian E. Lapointe, Kevin S. McCann
Coral reefs are facing a constant barrage of human impacts, including eutrophication, overharvesting and climate change. While the local effects of overharvesting have been well-studied, regional nutrient loading from anthropogenic activities on land and global climate change-induced disturbances are increasing in magnitude and necessitating cross-scale multi-stressor approaches for coral reef ecology. Here, we expand on longstanding theory to develop an integrated multi-stressor framework for coral reefs. We show that: (i) The geometry of a simple, empirically motivated model suggests nutrients and harvesting can operate similarly, and synergistically, in driving shifts from coral- to algae-dominated reefs, resulting in clear context-dependent management implications; and (ii) this same geometry suggests climate-driven coral mortality can drive the presence of long transients and climate-driven alternate states, even in moderately impacted ecosystems. Reefs seemingly in a “safe space” based on individual stressors may in fact be much more susceptible to increasingly frequent storms and bleaching events in multi-stressor conditions. By integrating these findings with general ecological and theoretical concepts, we suggest that responses in benthic composition may act as “signatures of change” to multi-stressors, allowing us to develop a predictive and generalizable multi-stressor framework for coral reefs under global change. In line with this theory, we detail empirical evidence from Barbados of historical changes in reef composition and multi-stressor impacts within our framework. By bridging coral reef ecology and general ecological concepts, we can better understand ecosystem functioning and resilience in these important yet highly threatened systems.
{"title":"Toward a Multi-stressor Theory for Coral Reefs in a Changing World","authors":"Carling Bieg, Henri Vallès, Alexander Tewfik, Brian E. Lapointe, Kevin S. McCann","doi":"10.1007/s10021-023-00892-8","DOIUrl":"https://doi.org/10.1007/s10021-023-00892-8","url":null,"abstract":"<p>Coral reefs are facing a constant barrage of human impacts, including eutrophication, overharvesting and climate change. While the local effects of overharvesting have been well-studied, regional nutrient loading from anthropogenic activities on land and global climate change-induced disturbances are increasing in magnitude and necessitating cross-scale multi-stressor approaches for coral reef ecology. Here, we expand on longstanding theory to develop an integrated multi-stressor framework for coral reefs. We show that: (i) The geometry of a simple, empirically motivated model suggests nutrients and harvesting can operate similarly, and synergistically, in driving shifts from coral- to algae-dominated reefs, resulting in clear context-dependent management implications; and (ii) this same geometry suggests climate-driven coral mortality can drive the presence of long transients and climate-driven alternate states, even in moderately impacted ecosystems. Reefs seemingly in a “safe space” based on individual stressors may in fact be much more susceptible to increasingly frequent storms and bleaching events in multi-stressor conditions. By integrating these findings with general ecological and theoretical concepts, we suggest that responses in benthic composition may act as “signatures of change” to multi-stressors, allowing us to develop a predictive and generalizable multi-stressor framework for coral reefs under global change. In line with this theory, we detail empirical evidence from Barbados of historical changes in reef composition and multi-stressor impacts within our framework. By bridging coral reef ecology and general ecological concepts, we can better understand ecosystem functioning and resilience in these important yet highly threatened systems.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139482677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-05DOI: 10.1007/s10021-023-00893-7
Julia D. Monk, Emiliano Donadio, Justine A. Smith, Paula L. Perrig, Arthur D. Middleton, Oswald J. Schmitz
Animal carcass decomposition is an often-overlooked component of nutrient cycles. The importance of carcass decomposition for increasing nutrient availability has been demonstrated in several ecosystems, but impacts in arid lands are poorly understood. In a protected high desert landscape in Argentina, puma predation of vicuñas is a main driver of carcass distribution. Here, we sampled puma kill sites across three habitats (plains, canyons, and meadows) to evaluate the impacts of vicuña carcass and stomach decomposition on soil and plant nutrients up to 5 years after carcass deposition. Soil beneath both carcasses and stomachs had significantly higher soil nutrient content than adjacent reference sites in arid, nutrient-poor plains and canyons, but not in moist, nutrient-rich meadows. Stomachs had greater effects on soil nutrients than carcasses. However, we did not detect higher plant N concentrations at kill sites. The biogeochemical effects of puma kills persisted for several years and increased over time, indicating that kills do not create ephemeral nutrient pulses, but can have lasting effects on the distribution of soil nutrients. Comparison to broader spatial patterns of predation risk reveals that puma predation of vicuñas is more likely in nutrient-rich sites, but carcasses have the greatest effects on soil nutrients in nutrient-poor environments, such that carcasses increase localized heterogeneity by generating nutrient hotspots in less productive environments. Predation and carcass decomposition may thus be important overlooked factors influencing ecosystem functioning in arid environments.
{"title":"Predation and Biophysical Context Control Long-Term Carcass Nutrient Inputs in an Andean Ecosystem","authors":"Julia D. Monk, Emiliano Donadio, Justine A. Smith, Paula L. Perrig, Arthur D. Middleton, Oswald J. Schmitz","doi":"10.1007/s10021-023-00893-7","DOIUrl":"https://doi.org/10.1007/s10021-023-00893-7","url":null,"abstract":"<p>Animal carcass decomposition is an often-overlooked component of nutrient cycles. The importance of carcass decomposition for increasing nutrient availability has been demonstrated in several ecosystems, but impacts in arid lands are poorly understood. In a protected high desert landscape in Argentina, puma predation of vicuñas is a main driver of carcass distribution. Here, we sampled puma kill sites across three habitats (plains, canyons, and meadows) to evaluate the impacts of vicuña carcass and stomach decomposition on soil and plant nutrients up to 5 years after carcass deposition. Soil beneath both carcasses and stomachs had significantly higher soil nutrient content than adjacent reference sites in arid, nutrient-poor plains and canyons, but not in moist, nutrient-rich meadows. Stomachs had greater effects on soil nutrients than carcasses. However, we did not detect higher plant <i>N</i> concentrations at kill sites. The biogeochemical effects of puma kills persisted for several years and increased over time, indicating that kills do not create ephemeral nutrient pulses, but can have lasting effects on the distribution of soil nutrients. Comparison to broader spatial patterns of predation risk reveals that puma predation of vicuñas is more likely in nutrient-rich sites, but carcasses have the greatest effects on soil nutrients in nutrient-poor environments, such that carcasses increase localized heterogeneity by generating nutrient hotspots in less productive environments. Predation and carcass decomposition may thus be important overlooked factors influencing ecosystem functioning in arid environments.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139374567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-04DOI: 10.1007/s10021-023-00891-9
Saara Mäkelin, Aleksandra M. Lewandowska, Iván F. Rodil, Agnes M. L. Karlson, Christoph Humborg, Anna Villnäs
Benthic macrofauna modifies carbon and nutrient retention and recycling processes in coastal habitats. However, the contribution of benthic consumers to carbon and nutrient storage and recycling shows variation over spatial scales, as the benthic community composition changes in response to differences in environmental conditions. By sampling both shallow sandy and deep muddy sediments across a land-to-sea gradient in the northern Baltic Sea, we explored if benthic community composition, stoichiometry and process rates change in response to alterations in environmental conditions and food sources. Our results show that benthic faunal biomass, C, N, and P stocks, respiration rate and secondary production increase across the land-to-sea gradient in response to higher resource quality towards the open sea. The seston δ13C indicated terrestrial runoff and δ15N sewage input at the innermost study sites, whereas more fresh marine organic matter towards the open sea boosted benthic faunal carbon storage, respiration rate, and secondary production, that is, the generation of consumer biomass, which are essential processes for carbon turnover in this coastal ecosystem. Also, biological factors such as increasing species richness and decreasing biomass dominance of the clam Macoma balthica were significant in predicting benthic faunal C, N, and P stocks and process rates, especially at sandy sites. Interestingly, despite the variation in food sources, the benthic faunal C:N:P ratios remained stable across the gradient. Our results prove that human activities in the coastal area can influence the important links between biodiversity, structure, and process rates of benthic communities by modifying the balance of available resources, therefore hampering the functioning of coastal ecosystems.
{"title":"Linking Resource Quality and Biodiversity to Benthic Ecosystem Functions Across a Land-to-Sea Gradient","authors":"Saara Mäkelin, Aleksandra M. Lewandowska, Iván F. Rodil, Agnes M. L. Karlson, Christoph Humborg, Anna Villnäs","doi":"10.1007/s10021-023-00891-9","DOIUrl":"https://doi.org/10.1007/s10021-023-00891-9","url":null,"abstract":"<p>Benthic macrofauna modifies carbon and nutrient retention and recycling processes in coastal habitats. However, the contribution of benthic consumers to carbon and nutrient storage and recycling shows variation over spatial scales, as the benthic community composition changes in response to differences in environmental conditions. By sampling both shallow sandy and deep muddy sediments across a land-to-sea gradient in the northern Baltic Sea, we explored if benthic community composition, stoichiometry and process rates change in response to alterations in environmental conditions and food sources. Our results show that benthic faunal biomass, C, N, and P stocks, respiration rate and secondary production increase across the land-to-sea gradient in response to higher resource quality towards the open sea. The seston <i>δ</i><sup>13</sup>C indicated terrestrial runoff and <i>δ</i><sup>15</sup>N sewage input at the innermost study sites, whereas more fresh marine organic matter towards the open sea boosted benthic faunal carbon storage, respiration rate, and secondary production, that is, the generation of consumer biomass, which are essential processes for carbon turnover in this coastal ecosystem. Also, biological factors such as increasing species richness and decreasing biomass dominance of the clam <i>Macoma balthica</i> were significant in predicting benthic faunal C, N, and P stocks and process rates, especially at sandy sites. Interestingly, despite the variation in food sources, the benthic faunal C:N:P ratios remained stable across the gradient. Our results prove that human activities in the coastal area can influence the important links between biodiversity, structure, and process rates of benthic communities by modifying the balance of available resources, therefore hampering the functioning of coastal ecosystems.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139374340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-26DOI: 10.1007/s10021-023-00890-w
Patrick R. Hodgson, Madison L. Annis, Angela Hsuan Chen, Molly R. Fraser, Dan J. Lee, Aaron I. Stanton, Jason Racela, Allison L. Gill
Soil organic matter (SOM) is a major global carbon (C) pool vulnerable to ongoing warming, as microbial SOM decomposition and CO2 respiration are sensitive to temperature. We characterized the edaphic characteristics that explain variation in soil C concentration, cycling, and temperature sensitivity (Q10) across two sites of differing elevation, forest community composition, and mineral parent material at Hopkins Memorial Forest, Williamstown, Massachusetts, USA. We found that the upper site maintained significantly higher surface soil C concentration, despite similar litterfall inputs across sites. We found large differences in the fraction of total soil C that is protected from microbial decomposition, with enhanced physical protection in macroaggregate-rich, upper site soils. Upper site plots maintain a higher relative abundance of plants producing lignin-rich litter, which may fuel aggregate formation and SOM protection. Experimental addition of glucose, vanillin, and lignin substrates produced broadly conserved respiratory responses across sites, suggesting that microbial communities maintain similar decomposition capacity, although lignin addition induced slightly elevated respiration responses in upper relative to lower site plots. Seasonal Q10 of soil respiration was higher at the upper site and increased with soil potassium (K+) availability across plots, potentially reflecting K+ constraints on autotrophic and heterotrophic metabolic activity. Our findings suggest that variation in the extent of physical protection of soil C, particularly through macroaggregate formation, is an important mechanism for long-term soil C storage at the site. Despite enhanced SOM physical protection at the upper site, the higher temperature sensitivity of soil respiration may reduce soil C in the context of future warming.
土壤有机质(SOM)是全球主要的碳(C)库,容易受到持续变暖的影响,因为土壤有机质的微生物分解和二氧化碳呼吸对温度很敏感。我们研究了美国马萨诸塞州威廉斯敦霍普金斯纪念森林两个不同海拔高度、森林群落组成和矿物母质的地点的土壤碳浓度、循环和温度敏感性(Q10)变化的土壤特性。我们发现,尽管不同地点的降尘量相似,但上部地点的地表土壤碳浓度明显更高。我们发现,受微生物分解保护的土壤总碳含量存在很大差异,在富含大颗粒的上部土壤中,物理保护作用更强。上部地块中产生富含木质素的枯落物的植物相对数量较多,这可能会促进聚合体的形成和对 SOM 的保护。在实验中添加葡萄糖、香兰素和木质素基质会在不同地点产生大致相同的呼吸反应,这表明微生物群落保持着相似的分解能力,尽管添加木质素会导致上部地块的呼吸反应略高于下部地块。上部地块土壤呼吸作用的季节性 Q10 值较高,并且随着各地块土壤钾(K+)供应量的增加而增加,这可能反映了 K+ 对自养和异养代谢活动的限制。我们的研究结果表明,土壤碳物理保护程度的变化,特别是通过大团聚体的形成,是该地点土壤碳长期储存的一个重要机制。尽管上部地点的 SOM 物理保护作用增强,但土壤呼吸作用对温度的敏感性较高,在未来气候变暖的情况下可能会减少土壤碳储量。
{"title":"Biophysical Controls on Soil Carbon Cycling in a Northern Hardwood Forest","authors":"Patrick R. Hodgson, Madison L. Annis, Angela Hsuan Chen, Molly R. Fraser, Dan J. Lee, Aaron I. Stanton, Jason Racela, Allison L. Gill","doi":"10.1007/s10021-023-00890-w","DOIUrl":"https://doi.org/10.1007/s10021-023-00890-w","url":null,"abstract":"<p>Soil organic matter (SOM) is a major global carbon (C) pool vulnerable to ongoing warming, as microbial SOM decomposition and CO<sub>2</sub> respiration are sensitive to temperature. We characterized the edaphic characteristics that explain variation in soil C concentration, cycling, and temperature sensitivity (<i>Q</i><sub><i>10</i></sub>) across two sites of differing elevation, forest community composition, and mineral parent material at Hopkins Memorial Forest, Williamstown, Massachusetts, USA. We found that the upper site maintained significantly higher surface soil C concentration, despite similar litterfall inputs across sites. We found large differences in the fraction of total soil C that is protected from microbial decomposition, with enhanced physical protection in macroaggregate-rich, upper site soils. Upper site plots maintain a higher relative abundance of plants producing lignin-rich litter, which may fuel aggregate formation and SOM protection. Experimental addition of glucose, vanillin, and lignin substrates produced broadly conserved respiratory responses across sites, suggesting that microbial communities maintain similar decomposition capacity, although lignin addition induced slightly elevated respiration responses in upper relative to lower site plots. Seasonal <i>Q</i><sub><i>10</i></sub> of soil respiration was higher at the upper site and increased with soil potassium (K<sup>+</sup>) availability across plots, potentially reflecting K<sup>+</sup> constraints on autotrophic and heterotrophic metabolic activity. Our findings suggest that variation in the extent of physical protection of soil C, particularly through macroaggregate formation, is an important mechanism for long-term soil C storage at the site. Despite enhanced SOM physical protection at the upper site, the higher temperature sensitivity of soil respiration may reduce soil C in the context of future warming.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139054688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-18DOI: 10.1007/s10021-023-00888-4
Alexander J. Smith, Karen McGlathery, Yaping Chen, Carolyn J. Ewers Lewis, S. Doney, K. Gedan, Carly K. LaRoche, Peter Berg, Michael L. Pace, J. Zinnert, M. Kirwan
{"title":"Correction to: Compensatory Mechanisms Absorb Regional Carbon Losses Within a Rapidly Shifting Coastal Mosaic","authors":"Alexander J. Smith, Karen McGlathery, Yaping Chen, Carolyn J. Ewers Lewis, S. Doney, K. Gedan, Carly K. LaRoche, Peter Berg, Michael L. Pace, J. Zinnert, M. Kirwan","doi":"10.1007/s10021-023-00888-4","DOIUrl":"https://doi.org/10.1007/s10021-023-00888-4","url":null,"abstract":"","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-18DOI: 10.1007/s10021-023-00889-3
Daniel W. Colson, Paul J. Morris, Mark W. Smith, Håkan Rydin, Gustaf Granath, Duncan J. Quincey
Raised bogs are wetland ecosystems which, under the right climatic conditions, feature patterns of pool hollows and hummock ridges. The relative cover and the spatial arrangement of pool and ridge microforms are thought to be influential on peatland atmosphere carbon gas fluxes and plant biodiversity. The mechanisms responsible for the formation and maintenance of pools, and the stability of these features in response to warming climates, remain topics of ongoing research. We employed historical aerial imagery, combined with a contemporary uncrewed aerial vehicle survey, to study 61 years of changes in pools at a patterned raised bog in central Sweden. We used a pool inheritance method to track individual pools between image acquisition dates throughout the time series. These data show a rapid loss of open-water pool area during the study period, primarily due to overgrowth of open-water pools by Sphagnum. We postulate that these changes are driven by ongoing climate warming that is accelerating Sphagnum colonisation. Open-water pool area declined by 26.8% during the study period, equivalent to a loss of 1001 m2 y−1 across the 150-hectare site. This is contradictory to an existing theory that states pools are highly stable, once formed, and can only convert to a terrestrial state through catastrophic drainage. The pool inheritance analysis shows that smaller pools are liable to become completely terrestrialised and expire. Our findings form part of a growing body of evidence for the loss of open-water habitats in peatlands across the boreal and elsewhere.
{"title":"Six Decades of Changes in Pool Characteristics on a Concentric-Patterned Raised Bog","authors":"Daniel W. Colson, Paul J. Morris, Mark W. Smith, Håkan Rydin, Gustaf Granath, Duncan J. Quincey","doi":"10.1007/s10021-023-00889-3","DOIUrl":"https://doi.org/10.1007/s10021-023-00889-3","url":null,"abstract":"<p>Raised bogs are wetland ecosystems which, under the right climatic conditions, feature patterns of pool hollows and hummock ridges. The relative cover and the spatial arrangement of pool and ridge microforms are thought to be influential on peatland atmosphere carbon gas fluxes and plant biodiversity. The mechanisms responsible for the formation and maintenance of pools, and the stability of these features in response to warming climates, remain topics of ongoing research. We employed historical aerial imagery, combined with a contemporary uncrewed aerial vehicle survey, to study 61 years of changes in pools at a patterned raised bog in central Sweden. We used a pool inheritance method to track individual pools between image acquisition dates throughout the time series. These data show a rapid loss of open-water pool area during the study period, primarily due to overgrowth of open-water pools by <i>Sphagnum</i>. We postulate that these changes are driven by ongoing climate warming that is accelerating <i>Sphagnum</i> colonisation. Open-water pool area declined by 26.8% during the study period, equivalent to a loss of 1001 m<sup>2</sup> y<sup>−1</sup> across the 150-hectare site. This is contradictory to an existing theory that states pools are highly stable, once formed, and can only convert to a terrestrial state through catastrophic drainage. The pool inheritance analysis shows that smaller pools are liable to become completely terrestrialised and expire. Our findings form part of a growing body of evidence for the loss of open-water habitats in peatlands across the boreal and elsewhere.</p>","PeriodicalId":11406,"journal":{"name":"Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138741669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}