Including Carbon Sequestration Research Articles

Ecosystem services assessment and sensitivity analysis based on ANN model and spatial data: A case study in Miaodao Archipelago

Ecosystem services (ESs) assessment is an important basis for the island protection and utilization plan development. The application of artificial neural network (ANN) to ESs assessment is a new attempt. Herein, an ANN model for the assessment of 5 ESs including carbon sequestration (CS), habitat quality (HQ), nutrient retention (NR), sediment retention (SR), and water yield (WY) of Miaodao Archipelago is established by taking the advantages of InVEST model and the powerful spatial analysis function of the geographic information system (GIS), as well as the self-learning and self-adaptive characteristics, and prediction function of ANN. The independent sample test shows that the correlation coefficient between the model prediction value and InVEST model simulation value is 0.88 (P < 0.001), and the average absolute error of the simulation is 10.33%. The 5 ESs of the Miaodao Archipelago in 2019 was then simulated using the trained model. The comparison with the corresponding data in 2010 suggests that CS, SR and HQ are in decline, while WY is in upward. The impacts of land use on ESs are then analyzed with the ecosystem service change index (ESCI) in different land use scenarios. An ANN model based quantitative method for evaluating the sensitivities of ecosystem service (ES) to typical environmental factors is proposed. The modeling results suggest that the ANN based model can accurately quantify the importance of different environmental factors to the island ESs, and give the comprehensive impact of multiple factors on the ESs. Therefore, the ANN model combined spatial data analysis provides an important means for ESs assessment and sensitivity analysis.

Improved ginseng production under continuous cropping through soil health reinforcement and rhizosphere microbial manipulation with biochar: a field study of Panax ginseng from Northeast China.

ABSTRACTThe production of ginseng, an important Chinese medicine crop, has been increasingly challenged by soil degradation and pathogenic disease under continuous cropping in Northeast China. In a field experiment, an Alfisol garden continuously cropped with Chinese ginseng (Panax ginseng C. A. Meyer) was treated with soil amendment at 20 t ha−1 with maize (MB) and wood (WB) biochar, respectively, compared to conventional manure compost (MC). Two years after the amendment, the rooted topsoil and ginseng plants were sampled. The changes in soil fertility and health, particularly in the soil microbial community and root disease incidence, and in ginseng growth and quality were portrayed using soil physico-chemical assays, biochemical assays of extracellular enzyme activities and gene sequencing assays as well as ginsenoside assays. Topsoil fertility was improved by 23% and 39%, ginseng root biomass increased by 25% and 27%, and root quality improved by 6% and 18% with WB and MB, respectively, compared to MC. In the ginseng rhizosphere, fungal abundance increased by 96% and 384%, with a significant and insignificant increase in bacterial abundance, respectively, under WB and MB. Specifically, the abundance of Fusarium spp. was significantly reduced by 19–35%, while that of Burkholderia spp. increased by folds under biochar amendments over MC. Relevantly, there was a significant decrease in the abundance proportion of pathotrophic fungi but a great increase in that of arbuscular mycorrhizal fungi, along with an enhanced microbial community network complexity, especially fungal community complexity, under biochar amendments. Thus, biochar, particularly from maize residue, could promote ginseng quality production while enhancing soil health and ecological services, including carbon sequestration, in continuously cropped fields.

Geospatial assessment of urban ecosystem disservices: An example of poisonous urban trees in Berlin, Germany

Urban trees play an important role in green infrastructure planning for the ecosystem services they provide. These services include carbon sequestration, the provision of clean air through oxygen production and filtering of airborne pollutants, and the offsetting of the urban heat island effect by providing shade and cooling. In addition to the well-studied positive effects of urban trees, under specific conditions, there are some unwanted side effects that need to be considered. Such negative side effects, such as allergies caused by tree pollen, traffic hazards from falling trees or tree parts or damage from roots or branches in resource supply or waste disposal infrastructures, are termed ecosystem disservices. An ecosystem disservice that is not very often illuminated in the urban context is the presence of poisonous urban trees. This paper provides a spatially explicit view of the distribution of poisonous urban trees in the city of Berlin, relating the spatial distribution of the hazard from this urban ecosystem disservice with the conditions under which it can have the most damaging effect by considering nearby playgrounds and areas with a high population density of children under 5 years old, the most vulnerable group within the urban population.

The impact of agricultural land afforestation on soil water content in Central Bohemia

In the Czech Republic, the afforestation of agricultural land has been supported by providing subsidies from the government and the European Union. Afforestation of less-productive agricultural land provides many benefits including carbon sequestration, soil erosion control, biodiversity, water retention, cooling, social benefits, decreasing noise and light pollution, increasing air quality, wind speed reduction, oxygen production, wood production and non-wood products. In some aspects, it is possible to produce wood of the same quality on former agricultural land compared to permanent forest land. In this study, we attempted to find out the course of temperatures and volumetric water content as well as some other physical soil properties (at depths of 20, 40 and 60 cm) 9 years after the afforestation of agricultural land (warm, mild dry region of the Czech Republic) with a mixture of broadleaved tree species (Quercus robur L., Quercus rubra L. and Acer platanoides L.) or monospecific Pinus sylvestris L. stand; the study was performed in the period from April to the beginning of November 2020. Concerning the studied physical soil properties, the value of bulk density was higher (and total porosity lower) at a depth of 20 cm in Pinus sylvestris L. compared with agricultural land or the mixture of broadleaves; the water stability of soil aggregates was higher after the afforestation with the mixture of broadleaves. The temperature was lower in the soil of afforested plots (at all studied depths) compared to the agriculturally used land. Differences in rainfall interception, transpiration, soil&lt;br /&gt;(and forest floor) properties and other factors could influence the obtained values of water content in the soil of the studied plots. The average volumetric water contents were the highest in the plots with Scots pine (depth of 20 cm) and broadleaves (depth of 40 cm), and on the control plot (depth of 60 cm). The volumetric water content at a soil depth of 20 cm was not significantly (P &amp;gt; 0.05) different when the plot with Scots pine and agriculturally used land were compared. In all other cases and depths, the differences between plots were significant (P &amp;lt; 0.05).

Carbon sequestration potential in the rehabilitated mangroves in Indonesia

AbstractMangrove ecosystem provides important services for coastal communities. Unfortunately, this ecosystem has undergone physical pressures for decades, including land conversion for shrimp aquaculture. Rehabilitation of the degraded mangroves offers an effective solution for bringing back mangrove functions, including carbon sequestration capacity. This study aims to quantify carbon stock (CS) and sequestration rate of a rehabilitated mangrove ecosystem in Indonesia, particularly in Banten Province. We compared sediment CS and carbon accumulation rate (CAR) of a rehabilitated mangrove in Ciseukeut, Panimbang, with a natural mangrove in Cilintang, the Ujung Kulon National Park. The sediment CS to a depth of 1 m in a rehabilitated mangrove in Ciseukeut was higher than in a natural mangrove in Cilintang, constituting 364 Mg C ha−1 and 126 Mg C ha−1, respectively. However, CAR showed the opposite pattern, in which a natural mangrove showed an almost two‐fold higher rate (0.50 ± 0.42 Mg C ha−1 year−1) than that of a rehabilitated mangrove (0.27 ± 0.20 Mg C ha−1 year−1). Local hydrogeomorphological conditions play a role in affecting sediment CS and CAR in both sites. Enhancing hydrological modification can promote CAR, especially in an abandoned pond like in Ciseukeut. This study provided a knowledge base for suitable mangrove rehabilitation in the future that supports the Indonesian government's commitment to rehabilitating ca. 600,000 ha of degraded mangroves in Indonesia. Furthermore, the study also provides the first investigation of potential blue carbon for the world's natural heritage of the Ujung Kulon National Park.

Impact of Plant-Based Meat Alternatives on Cattle Inventories and Greenhouse Gas Emissions

New plant-based meat alternatives that aim to mimic the taste and texture of beef could have significant economic, environmental, and animal welfare impacts if they replace animal-based meats and reduce livestock production. Whether plant-based meat alternatives can achieve these ends depends on the extent to which consumers are willing to substitute for plant-based meat alternatives, the structure of the meat industry, and the inter-linkages of the livestock industry with the other parts of the economy. We construct and calibrate an economic model to estimate how a reduction in plant-based meat prices, or increases in demand for plant-based meat, in the United States affect cattle production. For every 10% reduction in price or increase in demand for plant-based meat alternatives, we estimate U.S. cattle production falls approximately 0.15%, U.S. cattle producers’ economic welfare falls by $300 million/year, and U.S. consumer welfare rises by $513 million/year. Increases in U.S. demand for plant-based meat alter trade patterns, leading to a reduction of beef imports and an increase in beef exports, a phenomenon that further reduces global greenhouse gas emissions and land use given the relative efficiency of U.S. beef production. For every 10% reduction in the price of plant-based meat alternatives, we estimate that the global reduction in emissions is equivalent to 0.41% of U.S. emissions from beef production and 1.4 % when including carbon sequestration from reforestation of abandoned cropland and pasture and reduced land-use change emissions.1 Even substantial reductions in prices of plant-based meat alternatives are unlikely to have substantive impacts on the U.S. cattle population and emissions, suggesting the need to also pursue alternative mitigation strategies, such as innovations to reduce the methane emissions per head.

Forest management with carbon scenarios in the central region of Mexico

The search for mechanisms to mitigate global warming has generated a series of proposals to reduce deforestation and promote conservation of forests as carbon stocks through financial or in-kind support. However, the economic implications of including carbon sequestration in forest for timber production have not been dealt with in depth, and the conditions in which combined production might be a profitable option to forest owners, particularly in Mexico, are unknown. The aim of this study was to quantify carbon sequestration in a central region of Mexico and evaluate the profitability of selling carbon credits as well as timber products. Data and information used comes from three inventories (2013, 2014 and 2016) taken in 160 permanent sampling plots of 400 m2 each; forest management costs per hectare were obtained through interviews to the landowners, and the profitability was assessed using the economic indicators Net Present Value (NPV), Internal Return Rate (IRR), Benefit-Cost Ratio (BCR), and Land Expected Value (LEV). The results indicate that, in areas of low productivity, carbon sequestration is profitable only at a low discount rate (3.5%) and a high price of the ton CO2e (USD 100 ha-1 year-1). However, under combined production, the optimal rotation periods are longer, depending on the discount rate and price of sequestered carbon. Therefore, timber production will continue to be the main economic activity, until the rules of operation of the different mechanisms created for carbon sequestration become more flexible and the carbon markets offer more attractive incentives.

Increasing fire and the decline of fire adapted black spruce in the boreal forest

Intensifying wildfire activity and climate change can drive rapid forest compositional shifts. In boreal North America, black spruce shapes forest flammability and depends on fire for regeneration. This relationship has helped black spruce maintain its dominance through much of the Holocene. However, with climate change and more frequent and severe fires, shifts away from black spruce dominance to broadleaf or pine species are emerging, with implications for ecosystem functions including carbon sequestration, water and energy fluxes, and wildlife habitat. Here, we predict that such reductions in black spruce after fire may already be widespread given current trends in climate and fire. To test this, we synthesize data from 1,538 field sites across boreal North America to evaluate compositional changes in tree species following 58 recent fires (1989 to 2014). While black spruce was resilient following most fires (62%), loss of resilience was common, and spruce regeneration failed completely in 18% of 1,140 black spruce sites. In contrast, postfire regeneration never failed in forests dominated by jack pine, which also possesses an aerial seed bank, or broad-leaved trees. More complete combustion of the soil organic layer, which often occurs in better-drained landscape positions and in dryer duff, promoted compositional changes throughout boreal North America. Forests in western North America, however, were more vulnerable to change due to greater long-term climate moisture deficits. While we find considerable remaining resilience in black spruce forests, predicted increases in climate moisture deficits and fire activity will erode this resilience, pushing the system toward a tipping point that has not been crossed in several thousand years.

Distribution, vertical migration, and trophic ecology of lanternfishes (Myctophidae) in the Southwestern Tropical Atlantic

Lanternfishes (Myctophidae) are among the most abundant, widespread, and diverse fish groups in the world ocean. They account for a significant part of oceanic fish biomass and play crucial roles in various ecosystem processes, including carbon sequestration and nutrient recycling. However, despite the increasing risks they face (e.g. global warming, plastic pollution, and exploitation of deep-sea resources), many aspects of the lanternfishes ecology still remain poorly known. Here, we investigate the species composition, vertical migration, and trophic ecology of lanternfishes in the Southwestern Tropical Atlantic (SWTA) and the influence of physicochemical factors on their horizontal structuring. We show that lanternfishes are a highly diverse and an abundant fish family of the SWTA, comprising at least 33 species and contributing 40% of all fish collected (in number). We reveal that some of these species may differ in their patterns of prey composition and migratory behaviour, leading to multidimensional niches, underestimated trophic links (e.g. gelatinous organisms), and several mechanisms to avoid competitive exclusion. At least 73% of the lanternfish species reported here seem to migrate to the surface to feed at night. Additionally, they are a central food source for mesopelagic and bathypelagic predators, thereby connecting shallow and deep-sea ecosystems. Finally, we show that the structure of lanternfish assemblages is not strongly affected by environmental conditions analysed here (i.e., throughout the thermohaline structure and current systems), leading to weak horizontal assemblage separation.

Managing flood risks in a changing climate

Managing flood risks in a changing climate

Time to Revisit Oil Palm-Livestock Integration in the Wake of United Nations Sustainable Development Goals (SDGs)

To date, the idea of using livestock animals as biological tools to manage weeds, sequester carbon, and boost food security in oil palm plantations has not been seriously considered by industry stakeholders of major producing countries (e.g., Indonesia, Malaysia, Thailand, Colombia, and Nigeria). We revisit the integration of oil palm cultivation with livestock farming as a silvopastoral agroforestry practice in the wake of Sustainable Development Goals (SDGs). Oil palm-livestock integration has the potential to promote sustainable palm oil production because it can provide multiple environmental and socio-economic benefits, including carbon sequestration, restoring top soil, improving ecosystem biodiversity, reducing pesticide and fertilizer inputs, and boosting national food security. In contrast to monocultural outputs of most conventional plantations, an oil palm silvopastoral system is an ideal way to address the global food insecurity challenge as it produces bioenergy, vegetable oil/fat and animal-based protein sources (e.g., red meat). In addition, the potential of contract targeted grazing could be considered as a new type of business and income diversification for rural people. Oil palm-livestock integration is a strategy by the palm oil industry to achieve multiple SDGs. Out of the 17 SDGs, oil palm-livestock integration is likely to deliver nine SDGs. Palm oil certification bodies should recognize oil palm-livestock integration as a biological control method in weed management practices. We recommend that oil palm-livestock integration should be promoted to revitalize sustainable palm oil production and strategic biodiversity conservation policy. Policy makers should encourage major players in the palm oil industry to practice oil palm-livestock integration.

We need biosphere stewardship that protects carbon sinks and builds resilience

Earth’s biosphere, its extraordinary and complex web of species and ecosystems on land and in the oceans, drives the life-sustaining cycles of water and other materials that enable all life on Earth to thrive. The biosphere is also a principal driver of immense negative feedback loops in the Earth system that stabilize atmospheric CO2 concentrations and thereby global climate—including carbon sequestration by vegetation, soils, and the oceans. As such, Earth’s ecosystems have played a central role in keeping our planet’s climate system unusually stable throughout the last 11,700 years (i.e., the inter-glacial Holocene). During this epoch, global mean temperatures have oscillated only about 1 °C around the pre-industrial average, providing the unique conditions that allowed human civilizations to flourish. Today, ocean and land ecosystems remove around 50% of anthropogenic CO2 emissions from the atmosphere each year (1), an extraordinary biophysical feat, given that these emissions have risen from approximately 4 gigatonnes of carbon (GtC) per year in 1960 to around 11 GtC per year today. Put another way, half our “climate debt” is removed, for free, by the biosphere every year—a vast subsidy to the world economy. Safeguarding the biosphere from further degradation or collapse is an existential challenge for humanity. There are important steps we can take to contain the damage. Image credit: Shutterstock/Kritskiy-ua. The recent Working Group 1 report of the sixth assessment of the Intergovernmental Panel on Climate Change (IPCC) confirmed this major nature contribution to climate stability, estimating the cumulative carbon sequestration by land and oceans to be 56% of all human-caused emissions between 1850 and 2019 (2). All major global climate models whose simulations give us hope of meeting the target of the Paris Climate Agreement—to keep warming well below 2 °C—take the continued provision of this gigantic biosphere endowment for granted, merely … [↵][1]1To whom correspondence may be addressed. Email: johan.rockstrom{at}pik-potsdam.de. [1]: #xref-corresp-1-1

Seagrass contribution to blue carbon in a shallow karstic coastal area of the Gulf of Mexico.

Seagrass meadows provide multiple ecosystem services, including carbon sequestration. However, seagrass meadows are among the most threatened ecosystems worldwide. Determining the magnitude of the carbon stocks in seagrass meadows at the regional scale allows for the estimation of their global magnitude and identification of their importance in regional environmental mitigation strategies. The objective of the present study was to determine the structure of seagrass meadows in the Los Petenes Biosfera Reserve (LPBR) and evaluate their contributions to sinks of carbon in this system, located in Yucatan, which is considered the region with the largest seagrass extension in Mexico. Analyses of the seagrass meadows were executed following standardized protocols (spectral analysis, and isotope and carbon stock analyses). The LPBR stores an average of 2.2 ± 1.7 Mg C ha−1 in living biomass and 318 ± 215 Mg C ha−1 in sediment (top 1 m), and this carbon stock decreases with water depth. The seagrass community extends 149,613 ha, which represents the largest organic carbon stock (47 Tg C) documented in seagrass meadows in Mexico. Macroalgae and seagrass represent 76% of the organic carbon stored in sediment. If LPBR seagrass meadows are lost due to natural or anthropogenic impacts, 173 Tg CO2eqemissions could be released, which corresponds to the emissions generated by fossil fuel combustion of 27% of the current Mexican population. This information emphasizes the importance of seagrass meadows as a carbon sink in the region and their contribution to climate change mitigation, thus allowing for the implementation of necessary conservation strategies.

Approaches to delineate aggregates in intact soil using X-ray imaging

Soil structure refers to the spatial arrangement of primary soil particles and pores, and is known to influence a variety of soil functions including carbon sequestration and water holding capacity. At present, research in this field is often divided, focusing either on pores where pore networks are investigated in undisturbed soil or on solids where isolated soil aggregates are commonly studied. The choice of approach depends on the needs and traditions in different disciplines of soil science. While there is much debate regarding how well these viewpoints relate to each other, there have been only marginal research efforts undertaken to compare them quantitatively. In this study, we presented and evaluated methods to identify 3-D subunits in X-ray images of eight undisturbed soil samples that we interpreted as macroaggregates, and compared these to to results from drop-shatter tests. Here, we exploited the cohesive forces of water that induces shrinkage cracks under drying. Despite promising trends, comparisons between image and drop-shatter test derived aggregate properties remained inconclusive. Nevertheless, our results encourage further investigations on larger sample sets and different observation scales. The here presented and discussed aggregate delineation methods illustrate an approach to harmonize soil structure characterization in terms of both pore-networks and soil aggregation. For example, respective extended approaches may be developed to evaluate the locations of microaggregates within macroaggregates.

Global application of an unoccupied aerial vehicle photogrammetry protocol for predicting aboveground biomass in non-forest ecosystems.

Non‐forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non‐forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low‐stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R 2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave‐one‐out cross‐validation of 3.9%. Biomass per‐unit‐of‐height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1–10 ha−1. Photogrammetric approaches could provide much‐needed information required to calibrate and validate the vegetation models and satellite‐derived biomass products that are essential to understand vulnerable and understudied non‐forested ecosystems around the globe.

Vermont’s Forests Provide Many Ecosystem Services Including Carbon Sequestration and Climate Change Mitigation

Photo 1: Vista from the top of the gondola in Smugglers Notch, Mt Mansfield State Forest, Vermont. This photograph captures just how vast Vermont’s forests are. Forests account for approximately 76% of Vermont’s land area, making it the fourth most heavily forested state in the United States. Given this, policymakers in the state have identified forests as an important tool in the fight against climate change. The goal of this research was to evaluate the mitigation potential of a range of forest management scenarios applied across the state. Photo credit: Emily Stephens. Photo 2: Overlooking Nichols Pond, in Woodbury, Vermont. In addition to carbon sequestration, Vermont’s forests provide many ecosystem services including aesthetic and economic values. Vermont is one of the ultimate fall foliage destinations in the United States, with over one million visitors traveling to Vermont in October alone to take in the picturesque landscapes ablaze with autumn colors. When considering implementation of forest management practices and policies to enhance carbon sequestration, it is critical to also consider the impacts on the other benefits these forests provide. Photo credit: Emily Stephens. Photo 3: Kayaking on Groton Lake first thing in the morning, Groton State Forest, Vermont. In this study, we evaluate practical ways to sustainably manage forests and their products to reduce greenhouse gas emissions. This report can serve to inform policymakers on potential biophysical responses of Vermont's forests to various management scenarios. If a goal is to integrate carbon sequestration into broader forest management objectives, it will be important to minimize trade-offs with other ecosystem services, such as the recreational opportunities, water quality, and wildlife habitat that the state’s forests provide. Photo credit: Emily Stephens. These photographs illustrate the article “Opportunities for Forest Sector Emissions Reductions: A state-level analysis” by Alexa J. Dugan, Jeremy W. Lichstein, Al Steele, Juha M. Metsaranta, Steven Bick, David Y. Hollinger published in Ecological Applications. https://doi.org/10.1002/eap.2327

Combined Application of Biochar and Lime Increases Maize Yield and Accelerates Carbon Loss from an Acidic Soil

Biochar, an ecologically friendly soil amendment, is suggested for large-scale field application for its multiple potential benefits, including carbon sequestration, crop yield improvement, and the abatement of greenhouse gas emissions. However, it is unknown how effective it is in changing soil properties and its associated yield improvement when biochar is co-applied with lime in acidic soil. Here, we examined the effects of two different biochars, i.e., rice husk biochar (RHB) and oil palm empty fruit bunches biochar (EFBB), and lime on nutrient availability, the yield of maize, and soil CO2 emission of acid soil. Biochars were applied at two different rates (10 and 15 t ha−1) in combination with two rates of lime (100% and 75%), while the recommended rate of NPK fertilizers, 100% lime, and without any amendments (control) were also included. Hybrid sweet corn was grown in pots with 20 kg soils for 75 days. Plant performance and soil analyses were performed before and after crop maize cultivation while CO2 emission was recorded. Compared to the control, combined RHB biochars with lime significantly buffered soil pH and increased nutrient availability (e.g., P by 137%), while reducing Al and Fe concentration at harvest. These changes in soil properties significantly increased maize yield (by 77.59%) and nutrient uptake compared to the control. Between the two biochars, RHB was relatively more effective in making these changes than EFBB. However, this treatment contributed to a greater carbon loss as CO2 (209% and 145% higher with RHB and EFBB) from soil than the control. We believe that biochar-mediated buffering of soil pH is responsible for this change. Our results suggest that combined biochar application could bring desirable changes in soil properties and increase crop performance, although these effects can be short-lived.

A Fused Radar–Optical Approach for Mapping Wetlands and Deepwaters of the Mid–Atlantic and Gulf Coast Regions of the United States

Tidal wetlands are critically important ecosystems that provide ecosystem services including carbon sequestration, storm surge mitigation, water filtration, and wildlife habitat provision while supporting high levels of biodiversity. Despite their importance, monitoring these systems over large scales remains challenging due to difficulties in obtaining extensive up-to-date ground surveys and the need for high spatial and temporal resolution satellite imagery for effective space-borne monitoring. In this study, we developed methodologies to advance the monitoring of tidal marshes and adjacent deepwaters in the Mid-Atlantic and Gulf Coast United States. We combined Sentinel-1 SAR and Landsat 8 optical imagery to classify marshes and open water in both regions, with user’s and producer’s accuracies exceeding 89%. This methodology enables the assessment of marsh loss through conversion to open water at an annual resolution. We used time-series Sentinel-1 imagery to classify persistent and non-persistent marsh vegetation with greater than 93% accuracy. Non-persistent marsh vegetation serves as an indicator of salinity regimes in tidal wetlands. Additionally, we mapped two invasive species: wetlands invasive Phragmites australis (common reed) with greater than 80% accuracy and deepwater invasive Trapa natans (water chestnut) with greater than 96% accuracy. These results have important implications for improved monitoring and management of coastal wetlands ecosystems.

Old-growth attributes in a maturing secondary Indiana state forest: an opportunity for balanced management1

Primary old-growth forests are rare in the state of Indiana and are found only in small, isolated patches of nature preserves. Recent research underscores the values of large tracts of secondary old-growth (referred to in this paper as “older” forests), including carbon sequestration, forest resiliency, mitigation of climate change impacts, and conservation of biological diversity. Due to historical management, many portions of Indiana state forests are maturing, and yet the “older” successional stage is underrepresented. One of these maturing forests, the site of our study, is in south-central Indiana within the Back Country Area (BCA) of the Morgan-Monroe/Yellowwood State Forest (two state forests, herein called a complex, including parcels in three counties with the largest block of forests spanning Brown and Monroe counties). Our study of the forest structure of the BCA addresses the following questions: (a) Is this mature forest developing ecological attributes of old-growth forests, thus making it a good candidate for an older forest reserve? (b) Does this forest support the plant community characteristic of natural areas of Indiana? We analyzed forest stand metrics, coarse woody debris and snags, age of the largest live trees, and the floristic quality of the herbaceous layer. We then compared these data with published accounts from Indiana nature preserves. Metrics such as tree basal area, number of large-diameter trees, and number of snags are within the range of those measured in existing old-growth forests of Indiana. Analysis of tree cores and log cross-sections shows that 78% of the sample trees were over 100 yr old, with 24% over 130 yr, which is also comparable to old-growth forest nature preserves in the state. The metrics of the Floristic Quality Assessment of the broader plant community of the BCA are comparable to or higher than the metrics from published assessments of Indiana nature preserves. Collectively, the attributes measured indicate that the BCA supports a maturing secondary forest with old-growth characteristics. In the absence of further timber harvest, the BCA as a reserve could reach older forest status within 50 yr. Our study demonstrates that the BCA forest is a prime candidate for an older forest reserve. This study of the BCA could also serve as a model for future assessments of potential older forest reserves in other state forests. Reserves of older forests free from harvest are not incompatible with other management goals and can be a valuable part of a broader-scale management plan. These forest reserves should be promoted across the state to increase the representation within Indiana's state forest system of late-successional secondary forest exhibiting ecological attributes of old-growth forests, thereby enhancing the role of state forests in biodiversity protection and climate mitigation.

Multilevel modelling of impacts of human and natural factors on ecosystem services change in an oasis, Northwest China

Clarifying driving mechanisms of ecosystem services changes is key to sustainable ecosystem management. This study evaluated three key ecosystem services, including carbon sequestration (proxied by net primary production, NPP), water yield, and soil conservation in Zhanyge during 1990-2015, and applied multilevel modeling to examine the impacts of sub-watershed level natural factors and county level human factors on ecosystem services changes. The results showed the ecological vulnerable Qilian mountain area possessed high values of these ecosystem services. During 1990-2015, NPP and water yield increased, and soil conservation decreased. Results of the multilevel models indicated that natural and human factors drove ecosystem service changes in various degrees and directions and it was necessary to consider the scale dependence of the driving factors at different levels. Particularly, forest land, grassland and cultivated land expansion led to increase of NPP, water yield and soil conservation, grain productivity and agricultural machinery level had negative effects on water yield, while had positive impacts on soil conservation. Overall, it is necessary to strengthen ecological protection in the Qilian mountain area and strictly control cultivated land expansion balance to maintain sustainable development of ecosystem with comprehensively considering the effects of driving factors and local conditions.