Small-scale Ecosystem Research Articles

Empirical assessments of small-scale ecosystem service flows in rural mosaic landscapes in the Ethiopian highlands

Human activities have rapidly altered natural ecosystems worldwide, resulting in fragmented ecosystems that are either culturally or formally protected. These ecosystem patches can be critical for ecosystem services (ES) that support human well-being. In the Ethiopian highlands, the remaining church forests and wetlands have a unique conservation status and are part of the global priority areas for biodiversity conservation. ES flows from these ecosystems to surrounding benefiting areas lack local-scale field evidence data and are not well-understood. Here, we empirically quantify the distance-dependent flows for four ES: grass biomass, microclimate regulation, crop pollination, and soil erosion retention since they exhibit considerable variation in spatial scales and processes of ES flows. The effect of spatial distance on each ES benefit flow was analysed using spatially explicit empirical models. The key findings are as follows: (1) The benefit of ES varies significantly with distance to the source ecosystems. (2) ES supply is determined by the extent (fragmentation) and condition of ecosystems, together with ecosystem type. (3) The quantity and number of ES provided decreases with distance from the source, and beneficiaries up to 3 km of the source only receive one type of ES (grass biomass). Approximately 80 % of the benefiting areas are within a radius of 200 m from forests and wetlands. Bundles of multiple ES types are received at the frontiers of service-providing ecosystems, where number of benefits are compared at particular locations from the source point. The investigated ecosystems (440 km2) provided benefits to 8,770 km2 for the four types of ES. Our findings imply that non-linear effects of key ecosystem variables need to be considered when mapping the distance-dependent ES flows. This study helps to understand the spatial connectivity between ecosystems and beneficiaries in the human-nature interdependency, which is useful for developing different strategies for ES conservation.

Investigation of bacterial diversity from hybrid water sources to multiple terminal sites on an isolated island in the south China sea

Isolated islands are vulnerable to shortages in water availability, necessitating the use of hybrid water sources. There is a knowledge gap of unknown microbial diversity in the hybrid sources. The present study collected water samples from different water sources and water treatment processes on an isolated island in the South China Sea to explore microbial diversity in a full-element hybrid water supply system and analyze the effects of environmental factors. The primary conclusions were as follows: (a) Currently, chemical indices generally pass the WHO standards, except for high pH levels. (b) The driving factors for microbial diversity followed the order of type of source water > temperature > UV254 > turbidity > materials of containers > oxidation-reduction potential > pH > OD600 > ion concentration. Microbial dissimilarity was primarily affected by temperature and organic matter, while distribution distance had a slight effect on the dissimilarity in the small-scale ecosystem. (c) Biological and chemical safety standards restrict the application of atmospheric water using metal-organic frameworks while the balance of water influences the exploitation of freshwater lenses on the isolated island.

Assessment of ecosystem quality changes based on optimizing key indicators in Nanwenghe National Nature Reserve, Heilongjiang, China.

Net primary productivity (NPP) is an indicator to reflect the production capacity of terrestrial ecosystems, as well as a key indicator for ecological quality. NPP at large scale is difficult to be measured. At present, most of the assessment of ecosystem quality uses NPP products with low resolution, which cannot capture the detailed characteristics of the ecosystem and is not conducive to the assessment of ecosystem quality at small-scale. The establishment of a rapid and efficient assessment method for small-scale ecosystem quality will greatly promote the protection and restoration of ecosystems in China. We focused on the calculation method of ecosystem quality assessment and NPP, and optimized the calculation process of the NPP, and obtained NPP by remote sensing without ground observation data. We established a regression model for remote sensing inversion of leaf area index, and estimated the vegetation coverage by using dimidiate pixel model, developed a set of methods for rapid assessment of ecosystem quality by remote sensing. Taking Nanwenghe National Nature Reserve as an example, we evaluated the change of ecosystem quality from 2001 to 2022. The results showed that from 2001 to 2022, the ecosystem qua-lity of the reserve was good as a whole, and that the area with good and excellent quality accounted for more than 85% in 2022. High vegetation coverage was the backbone of the sustainable good ecosystem quality of the reserve. From 2001 to 2022, ecosystem quality of the reserve showed a trend of first decreasing and then increasing, with the lowest point of ecosystem quality in 2013. This method had achieved good results in the evaluation of ecosystem quality in Nanwenghe National Nature Reserve. The index optimization method proposed in this study could facilitate the rapid and accurate assessment of ecosystem quality in small-scale regions, and thus provides technical reference for the precise improvement of ecosystem quality.

Zoning and Optimization Strategies of Land Spatial Ecological Restoration in Liangjiang New Area of Chongqing Based on the Supply–Demand Relationship of Ecosystem Services

Ecological land restoration is necessary to develop a comprehensive land amalgamation strategy. Scientific ecological restoration zoning is crucial for the development of differentiated restoration strategies, as well as for the improvement of quality during construction. This study used a series of methods, such as the InVEST model, spatial autocorrelation, and coupling coordination degree models, using Liangjiang New Area as an example to quantify both regional ecosystem services supply and demand at the county and district levels. The land’s spatial ecological restoration zones were determined, and the optimization strategies based on the supply–demand matching and coordination relationship were presented. The results revealed the following: (1) A considerable difference was identified between the supply and demand of ecosystem services in Liangjiang New Area of Chongqing, with “high in the northeast and low in the southwest” spatial patterns for supply and “high in the southwest and low in the northeast” spatial patterns for demand; (2) The supply–demand matching relationship of ecosystem services in Liangjiang New Area of Chongqing was characterized by spatial mismatches of high supply and low demand and low supply and high demand, with an average coordination degree index of 0.2, indicating uncoordinated supply and demand; (3) Based on the supply–demand relationship of ecosystem services, the regional ecological base, and the functional orientation of upper planning, Liangjiang New Area was divided into four zones: high supply–low demand, low supply–high demand, and high supply–high demand zones, for which the respective optimization strategies were presented. In some ways, this study contributes to the existing research concerning the supply–demand relationship for small-scale ecosystem services in new development zones located in mountainous cities.

A review of forest visualization and forest fire simulation technology research

A review of forest visualization and forest fire simulation technology research

DNA Metabarcoding and Isolation by Baiting Complement Each Other in Revealing Phytophthora Diversity in Anthropized and Natural Ecosystems.

Isolation techniques supplemented by sequencing of DNA from axenic cultures have provided a robust methodology for the study of Phytophthora communities in agricultural and natural ecosystems. Recently, metabarcoding approaches have emerged as new paradigms for the detection of Phytophthora species in environmental samples. In this study, Illumina DNA metabarcoding and a conventional leaf baiting isolation technique were compared to unravel the variability of Phytophthora communities in different environments. Overall, 39 rhizosphere soil samples from a natural, a semi-natural and a horticultural small-scale ecosystem, respectively, were processed by both baiting and metabarcoding. Using both detection techniques, 28 out of 39 samples tested positive for Phytophthora. Overall, 1,406,613 Phytophthora internal transcribed spacer 1 (ITS1) sequences and 155 Phytophthora isolates were obtained, which grouped into 21 taxa, five retrieved exclusively by baiting (P. bilorbang; P. cryptogea; P. gonapodyides; P. parvispora and P. pseudocryptogea), 12 exclusively by metabarcoding (P. asparagi; P. occultans; P. psycrophila; P. syringae; P. aleatoria/P. cactorum; P. castanetorum/P. quercina; P. iranica-like; P. unknown sp. 1; P. unknown sp. 2; P. unknown sp. 3; P. unknown sp. 4; P. unknown sp. 5) and four with both techniques (P. citrophthora, P. multivora, P. nicotianae and P. plurivora). Both techniques complemented each other in describing the variability of Phytophthora communities from natural and managed ecosystems and revealing the presence of rare or undescribed Phytophthora taxa.

Revealing the differences of urban parks’ services to human wellbeing based upon social media data

Urban green spaces provide a range of services to urban residents; however, how these distinct spaces provide different services, if any, to human wellbeing has been seldom addressed. Using large volumes of social media data considering broad user groups and publicly available content, we developed a method to transform unstructured online comments into a structured assessment of nine categories of ecosystem services. An ‘ecosystem services lexicon’ was created based on 6853 words under twenty-eight subcategories of parks' services to human wellbeing using the word2vec model. The application of the ecosystem service lexicon to urban parks in Beijing revealed that all ecosystem services were perceivable to urban park users; however, the perception frequency of the ecosystem services varied across different parks. Additionally, the perceived ecosystem services were bundled together; four types of bundles were identified with varied dominant services. Technically, this study offered a novel technical procedure that can transfer unstructured free comments into a structured assessment of urban parks' perceived services to human wellbeing. Theoretically, the study revealed small-scale ecosystem service bundles from users' opinions and called for a further cross-scale understanding of ecosystem service bundles. Practically, the study findings can help inform evidence-based park policies, planning, and management.

Molecular change of dissolved organic matter and patterns of bacterial activity in a stream along a land-use gradient

Fluvial networks are globally relevant for the processing of dissolved organic matter (DOM). To investigate the change in molecular DOM diversity along the river course, high-field FTICR mass spectrometry and NMR spectroscopy of riverine DOM as well as bacterial abundance and activity were measured in a third order stream along a land-use gradient from pristine, agricultural to urban landscapes. DOM composition showed a clear evolution along the river course with an initial decrease of average oxidation and unsaturation followed by an increased relative abundance of CHNO and CHOS compounds introduced by agriculture and waste water, respectively. DOM composition was dominated by rather unsaturated CHO compounds (H/C ≤ 1) in headwaters and by more aliphatic molecules at downstream sites. Oxygenated functional groups shifted from aromatic ethers and hydroxyl groups to aliphatic carboxylic acids and aliphatic hydroxyl groups. This massive dislocation of oxygen significantly increased the diversity of atomic environments in branched aliphatic groups from headwater to downstream DOM. Mass spectra of DOM enabled the detection of compositional relationships to bacterial abundance and activity which was positively related to more aliphatic components (H/C > 1) and negatively related to unsaturated components. FTICR mass and NMR spectra corroborated the initial decline in DOM molecular diversity predicted by the River Continuum Concept (RCC) but demonstrated an anthropogenic increase in the molecular diversity of DOM further downstream. While the high DOM molecular diversity in first order headwater streams was the result of small scale ecosystem plurality, agriculture and waste water treatment introduced many components in the lower reaches. These anthropogenic influences together with massive bacterial oxidation of DOM contributed to a growth of molecular diversity of downstream DOM whose composition and structure differed entirely from those found in pristine headwaters.

Assessment of Small-Scale Ecosystem Conservation in the Brazilian Atlantic Forest: A Study from Rio Canoas State Park, Southern Brazil

The efficiency of the environmental management of a territory largely depends on previous surveys and systematic studies on the main elements and conditions of the physical environment. We applied remote sensing and digital image processing techniques (Principal Component Analysis and supervised classification) to Landsat imagery for analyzing the spatiotemporal land cover changes occurred in the Rio Canoas State Park in Brazil and its surrounding area from 1990 to 2016. Reforested areas around the park with exotic species is a part of the region’s economy and a number of industries depend on it for raw materials. However, it is a matter of concern to avoid contamination with such invasive species, due to the proximity of the Park. From 1990 to 2004, more than 95% of the study area was unchanged and showed minimal distinction in land cover over the 14 years. This was mainly due to the continuous presence of agricultural monocultures around the Park without significant increases (only 3.1% of land cover change during this period). Regarding the interior of the Rio Canoas State Park, from 1990 to 2004, there was no increase in the area of exposed soil. The analysis of the surrounding areas of the park from 2004 to 2016 showed that 5663.78 ha (12.2% of the area) of the land cover has been changed, in most areas, due to reforestation by Pinus sp. Notable changes occurred within the park (established in 2004) between 2004 and 2016—there was a partial regeneration of natural species diversity, a small number of invasive species (Pinus sp.) and removal of agricultural activities within the park, which contributed a 6.6% (75.45 ha) change in its land cover. We verified that 92.51% (1048.40 ha) of the areas inside the park were unchanged. The results demonstrated that actions were conducted to preserve the natural vegetation cover within the park and to reduce the impacts of anthropogenic activities, including the invasion of exotic species from the surrounding reforested areas into the natural habitat of the park. Given this, our study can aid the environmental management of the Park and its surrounding areas, enabling the monitoring of environmental legislation, the creation of a management plan, and can guide new action plans for the present study area and can be applied to other similar regions.

Integrating environmental parameters and economic benefits to analyze the ecological agriculture (EA) application in the mountain rice paddy system of Chongqing, China

BackgroundAgrochemicals, such as pesticides and fertilizers used in the current conventional agriculture (CA), have contaminating effects on environments as well as food, which pose significant risks to non-target organisms and even human health. Under these environmental pressures, ecological agriculture (EA), using organic fertilizer for crop growth, was developed without pesticides to substitute CA gradually worldwide. However, EA has still not become popular in the Chinese mountain area. To identify the major factors that influence the application of EA, rice cultivation between EA and CA was compared by analyzing soil physical–chemical properties, and soil bacterial and plant diversity in Chongqing. Besides, in considering the economic benefits of small-scale paddy ecosystem, net present value (NPV) method was applied for quantification and evaluation between EA and CA.ResultsThe rice yield of EA (3700 kg/ha) was significantly lower than that of CA (7500 kg/ha). Soil total nitrogen (TN, 2.24 ± 0.16 g/kg) and available potassium (AK, 70.67 ± 9.88 mg/kg) in CA were higher than those in EA, with amounts of 1.45 ± 0.18 g/kg (TN) and 54.00 ± 5.89 mg/kg (AK). Soil organic matter (SOM) of CA (55.6 ± 5.8 g/kg) was distinctly higher than that of EA (24.4 ± 1.43 g/kg), whereas pore water DOC concentration in EA (71.11 ± 7.28 mg/L) was higher than that in CA (61.07 ± 6.61 mg/L). Plant richness, bacterial diversity of ACE and Chao1 in EA were significantly higher than in CA (P < 0.05). The net present value (NPV) of EA was 3.72 CNY/m2, which was higher than that of CA (2.98 CNY/m2).ConclusionsThe relative high amounts of AP, pore water DOC and bacterial diversity revealed the improvement of soil properties by EA. Limitations on N and AK may be responsible for the low yield in small-scale EA of the current study. In addition, economic benefits, plant richness and bacterial diversity suggested EA application in China as well as worldwide to facilitate the sustainable development of the agroecosystem. However, animal diversity and quantification on economic benefits of ecological services should be considered in further research to promote the sustainability development of the agroecosystem.

The up-scaling of ecosystem functions in a heterogeneous world

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 (Chla) 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.

Heterotrophic and Autotrophic Soil Respiration under Simulated Dormancy Conditions

Carbon cycling research has increased over the past 20 years, but less is known about the primary contributors to soil respiration (i.e. heterotrophic and autotrophic) under dormant conditions. It is understood that soil CO2 effluxes are significantly lower during the winter of temperate ecosystems and assumed microorganisms dominate efflux origination. We hypothesized that heterotrophic contributions would be greater than autotrophic under simulated dormancy conditions. To test this hypothesis, we designed an experiment with the following treatments: combined autotrophic heterotrophic respiration, heterotrophic respiration, autotrophic respiration, no respiration, autotrophic respiration in vermiculite, and no respiration in vermiculite. Engelmann spruce seedlings and soil substrates were placed in specially designed respiration chambers and soil CO2 efflux measurements were taken four times over the course of a month. Soil microbial densities and root volumes were measured for each chamber after day thirty-three. Seedling presence resulted in significantly higher soil CO2 efflux rates for all soil substrates. Autotrophic respiration treatments were not representative of solely autotrophic soil CO2 efflux due to soil microbial contamination of autoclaved soil substrates; however, the mean autotrophic contributions averaged less than 25% of the total soil CO2 efflux. Soil microorganism communities were likely the primary contributor to soil CO2 efflux in simulated dormant conditions, as treatments with the greatest proportions of microbial densities had the highest soil CO2 efflux rates. Although this study is not directly comparable to field dormant season soil CO2 effluxes of Engelmann spruce forest, as snowpack is not maintained throughout this experiment, relationships, and metrics from such small-scale ecosystem component processes may yield more accurate carbon budget models.

Hydroecogeochemical effects of an epikarst ecosystem: case study of the Nongla Landiantang Spring catchment

A typical small-scale epikarst ecosystem usually consists of an epikarst zone, soil and vegetation. In this study, to determine the hydro-eco-geochemical effects of an epikarst ecosystem in subtropical humid area, the samples of vegetation, soil, soil microbes, rainfall, throughfall, stem flow, soil water and epikarst springs of Nongla Village, Mashan County, Guangxi in China were collected and analyzed. The research results have shown in the epikarst ecosystem, the conductivity, temporary hardness and total carbon increased continuously in hydro-ecochemical cycle; the vegetation–soil system conducted the transformation and transference of carbon in hydro-ecochemical cycle; the vegetation layer was the major source for organic carbon, while the soil layer was of the important chemical field for the conversion of organic/inorganic carbon and HCO3 –, which would affect the epikarst dynamical system; for most ions, the vegetation layer and shallow soil layer presented more leaching effect than absorption, in contrast, the deep soil layer behaved oppositely. The vegetation layer and shallow soil layer leached ions, and deep soil layer absorbed them. With the plant community presenting in a positive succession, the epikarst ecosystem trended to be stabilized gradually, which made the hydro-eco-geochemical effects to be adjusted and controlled more effectively.

Response of Sphagnum papillosum and Drosera rotundifolia to Reduced and Oxidized Wet Nitrogen Deposition

We transplanted Sphagnum ‘turfs’ containing abundant Drosera rotundifolia into an existing nitrogen deposition experiment at Whim Moss near Edinburgh. These mesocosms received simulated N deposition as either NH 4 + or NO 3 - , to give total N deposition rates of approximately 8, 16 or 32, or 64 kg N ha-1 year-1. Simulated N deposition was added in a realistic way (i.e., with rainfall throughout the year). The δ15N of this added N was elevated relative to background N. We measured the tissue chemistry and δ15N of Sphagnum papillosum and D. rotundifolia over two years after transplant. Our aim was to determine uptake of the deposited N and the impact on S. papillosum tissue chemistry and D. rotundifolia tissue chemistry and ecology. We found clear, significant impacts of N deposition on S. papillosum, with increased capitula N content and reduced C:N ratio. Increased δ15N indicated uptake of deposited N. The response of D. rotundifolia was less clear with impacts only at the highest rate of N deposition. There was no evidence of differential uptake of reduced or oxidized wet N deposition by either S. papillosum or D. rotundifolia. Using the natural abundance stable isotope method we estimated the minimum contribution of prey N to the total N in D. rotundifolia to be 35%. The results suggest that differences in the uptake of reduced or oxidized wet N deposition might not be ecologically significant when wet N deposition is added realistically. They also support the suggestion that a model of N dynamics in Sphagnum-dominated ecosystems that includes the role of Sphagnum as a small-scale ecosystem engineer, is required to predict vascular plant responses to N deposition accurately.

Molecular analysis of the prevalent microbiota of human male and female forehead skin compared to forearm skin and the influence of make-up

To compare the bacterial diversity of two different ecological regions including human forehead, human forearm and to estimate the influence of make-up. Twenty-two swab-scraped skin samples were analysed by profiling bacterial 16S rRNA genes using PCR-based sequencing of randomly selected clones. Of the 1056 clones analysed, 67 genera and 133 species-level operational taxonomic units (SLOTUs) belonging to eight phyla were identified. A core set of bacterial taxa was found in all samples, including Actinobacteria, Firmicutes, and Proteobacteria, but pronounced intra- and interpersonal variation in bacterial community composition was observed. Only 4·48% of the genera and 1·50% of the SLOTUs were found in all 11 subjects. In contrast to the highly diverse microbiota of the forearm skin, the forehead skin microbiota represented a small-scale ecosystem with a few genera found in all individuals. The use of make-up, including foundation and powder, significantly enlarged the community diversity on the forehead skin. Our study confirmed the presence of a highly diverse microbiota of the human skin as described recently. In contrast to forearm skin, gender does not seem to have much influence on the microbial community of the forehead skin. However, the use of make-up was associated with a remarkable increase in the bacterial diversity. This study enhances our knowledge about the highly complex microbiota of the human skin and demonstrates for the first time the significant effect of make-up on the bacterial diversity of the forehead skin.