Macrofaunal Diversity Research Articles

Trait-specific response of soil macrofauna to forest burning along a macrogeographic gradient

Fires change physical, chemical and biotic conditions of forest ecosystems. They also strongly affect soil macrofauna including key soil ecosystem engineers and regulators of soil-related processes in forest soils. However, due to a wide range of traits attributable to macroinvertebrates, the effect of forest burning on the macrofauna can be quite contrasting and still has not been quantified. We assessed the impact of forest fires on macrofauna taxonomic richness, abundance, total biomass and biomass of animals belonging to different functional traits in 20 forests burnt five years ago and 20 respective controls plots along a 3000-km-long north-south transect in European Russia which covered five major forest biomes (Mediterranean and broadleaved forests, southern, middle, and northern taiga).Actual abundance, biomass and taxonomic diversity of the soil macrofauna showed remarkable stability after burning and were specific to forest biome. However, soil macrofauna trait composition was consistently affected by fire. Relatively immobile taxa inhabiting top of the forest floor and sharing saprophagy suffer most from the consequences of fire five years after burning. We have concluded that resident groups of soil macrofauna sharing saprophagy seem to avoid top soil as one of the most damaged “frontiers” of the burnt soil ecosystem possibly due to both unfavorable hydroclimatic conditions in the burnt patches and lack of suitable resources. At the same time damaged soil surface creates a barrier in the way of the resident soil macroinvertebrate taxa distribution due to their inability to quickly transit patches with harsh conditions.

Evolução de atributos físicos, químicos e biológicos em solo hidromórfico sob sistemas de integração lavoura-pecuária no bioma Pampa

Resumo O objetivo deste trabalho foi avaliar a evolução de atributos físicos, químicos e biológicos de um solo hidromórfico sob sistemas de integração lavoura-pecuária, no bioma Pampa. O estudo foi desenvolvido em área experimental manejada com sistema plantio direto desde 2006, no Município de Capão do Leão, RS, em um Planossolo Háplico eutrófico típico. Três áreas foram utilizadas, com os seguintes tipos de manejo: área de lavoura sem pastejo; área de integração lavoura-pecuária (ILP), com soja e milho alternados em sucessão à pastagem de inverno; e campo nativo pastejado. As coletas de solo foram realizadas em duas épocas, em todas as áreas, às camadas de 0,00-0,05, 0,05-0,10 e 0,10-0,20 m profundidade, para análises dos seguintes atributos do solo: físicos, macroporosidade, microporosidade e densidade; químicos, carbono orgânico total, nitrogênio total e relação carbono/nitrogênio; e biológicos, diversidade e abundância da macrofauna edáfica. Na área com pastejo, a macroporosidade aumentou ao longo do tempo. A densidade do solo diminuiu na camada 0,00-0,05 m, enquanto o carbono orgânico total aumentou na camada de 0,10-0,20 m, em todas as áreas. O sistema de integração lavoura-pecuária favorece a abundância e a diversidade da fauna edáfica do solo.

First evaluation of foraminiferal metabarcoding for monitoring environmental impact from an offshore oil drilling site

At present, environmental impacts from offshore oil and gas activities are partly determined by measuring changes in macrofauna diversity. Morphological identification of macrofauna is time-consuming, expensive and dependent on taxonomic expertise. In this study, we evaluated the applicability of using foraminiferal-specific metabarcoding for routine monitoring. Sediment samples were collected along distance gradients from two oil platforms off Taranaki (New Zealand) and their physico-chemical properties, foraminiferal environmental DNA/RNA, and macrofaunal composition analyzed. Macrofaunal and foraminiferal assemblages showed similar shifts along impact gradients, but responded differently to environmental perturbations. Macrofauna were affected by hypoxia, whereas sediment grain size appeared to drive shifts in foraminifera. We identified eight foraminiferal molecular operational taxonomic units that have potential to be used as bioindicator taxa. Our results show that metabarcoding represents an effective tool for assessing foraminiferal communities near offshore oil and gas platforms, and that it can be used to complement current monitoring techniques.

Relating the visual soil structure status and the abundance of soil engineering invertebrates across land use change

Visual Evaluation of Soil Structure (VESS) method assesses the status of soil structural quality through the examination of soil physical characteristics and biological features. Consistent relationships between VESS scores and quantitative soil physical properties have been demonstrated. However, how VESS scores correlate with quantitative soil biological properties remains unknown. This study assessed relationships between soil structural quality responses to land use change (LUC) and alterations in soil macrofauna in arable tropical soils. We simultaneously measured soil structural quality through VESS method and the abundance and community structure of macrofauna in chronosequences of land uses comprising pasture and sugarcane crop along a 1000-km-long transect through two major tropical biomes in Brazil. Correlation matrix and principal component analysis (PCA) were performed to elucidate correlations between the measured variables. Average VESS scores were 2.5 and 3.0 for pasture to sugarcane, respectively, showing a deterioration of soil structural quality following LUC. Soil macrofauna abundance and richness, as well as the abundance of individual dominant macrofauna groups, consistently decreased from pasture to sugarcane. PCA explained 56.5% of the variance, with pasture soils mostly associated with macrofauna variables, and sugarcane soils grouped near the VESS score. Correlation matrix and PCA showed positive correlation between the deterioration of soil structure after LUC and reductions in the size of macrofaunal community, especially termites (rspearman=0.36; P=0.012). These results indicate that VESS scores correlate well with the abundance and richness of major soil engineers.

Changes in diversity, biomass and abundance of soil macrofauna, Parrotio-Carpinetum forest at organic and semi-organic horizons

Present study evaluates diversity, abundance and biomass of soil macrofauna in organic and semi-organic horizons in P arrotia persica -C arpinus betulus forest in Shast kola area. Totally 70 sample points were randomly selected from organic and semi-organic horizons then sampling was done by a rectangle 100 cm 2 area. Soil macrofauna were separated from soil samples by hand sorting and using Berlese funnel then dried at 60°C for 72h and weighted in 0.001 gr. With using taxonomic classification key, thirteen macrofauna orders were identified. Most of abundance of soil macrofauna in both soil horizons were allocated to Millipedes order. Changes in diversity, abundance and biomass of macrofauna in both soil horizons were calculated. The results showed Shannon diversity index, Simpson evenness and Margalef richness indices in semi-organic horizon were more than organic horizon. Abundance and biomass of macrofauna in semi-organic horizon were more than organic horizon.

Two-year temporal response of benthic macrofauna and sediments to hypoxia in a tropical semi-enclosed bay (Cienfuegos, Cuba).

Hypoxia is the depletion of dissolved oxygen below 2 mg O(2)/L. Relatively few studies on hypoxia and its effects on benthic macrofauna have been done in tropical marine ecosystems. This study describes the temporal response of the water column, sediments and macrofauna to seasonal hypoxia in a semi-enclosed bay (Cienfuegos, Caribbean Sea). The Calisito site was sampled monthly from June 2010 until February 2012, yielding 21 sampling times. At each sampling event water and sediment samples were collected for measuring the abiotic variables (temperature, salinity, dissolved oxygen, nutrients, redox potential discontinuity, silt/clay and organic matter content) and macrofauna (abundance and species richness). Temperature and surface salinity followed a typical temporal pattern during the summer/rainy and the winter/dry periods. Salinity stratification occurred in the rainy period, lasting three months in 2010 and six months in 2011. The bottom water dissolved oxygen indicated hypoxic and anoxic events during the wet periods of 2010 and 2011 associated with salinity stratification, low hydrodynamics and oxidation of the accumulated organic matter. Over the study period, 817 individuals were collected and identified. Polychaetes were the dominant group in terms of abundance (57 % of total) followed by mollusks (41%). Hypoxia (and occasionally anoxia) caused strong deleterious effects on the abundance and species richness of macrofaunal communities in the study site. The most abundant polychaetes were opportunistic species with high tolerance to hypoxic conditions: Prionospio steenstrupi, Polydora sp.and Paraprionospio pinnata. Most of them colonized relatively fast once hypoxia ended. Persistent species such as Caecum pulchellum and Parvanachis obesa were present during hypoxia with fluctuating densities and apparently recover to higher abundances when normoxic conditions are re-established. Macoma tenta and Tellina consobrina colonized approximately 1-2 months later than the first polychaete peak during normoxia. Probably, the deleterious effects of hypoxia on the macrofauna were intensified by negative interspecific relationships such as competition by suitable space and predation. The recolonization of macrofauna depended possibly on local transport by currents within the bay because the connection with the Caribbean Sea is relatively limited. In summary, seasonal hypoxia in Cienfuegos Bay influences the water and sediment geochemistry and reduces both the abundance and diversity of macrofauna.

Fertilidad del suelo con prácticas agroecológicas y manejo convencional en el cultivo de café

Las prácticas agroecológicas en plantaciones de café (Coffea arabica L.), son necesarias para el mantenimiento y aumento de la fertilidad de los suelos y el manejo sostenible de las plantaciones. Este estudio se realizó de junio de 2009 a enero de 2010 en el Jardín Botánico y en el Centro Experimental Campos Azules, en Masatepe, Nicaragua. El propósito fue evaluar dos prácticas agroecológicas y un manejo convencional en el cultivo de café y su influencia en la fertilidad física, química y biológica del suelo. Se utilizó un arreglo unifactorial en diseño bloques completo al azar (BCA) con tres repeticiones. Las variables fueron densidad aparente, porosidad, retención de agua, materia orgánica, nitrógeno total, carbono orgánico, pH, capacidad de intercambio catiónico y cuantificación de bacterias y hongos. No existen diferencias entre los componentes de la fertilidad física y química del suelo, sin embargo, los sistemas con prácticas agroecológicas registran mayor porosidad y retención de humedad, y menor densidad aparente; así como valores más altos de materia orgánica, capacidad de intercambio catiónico, carbono orgánico, nitrógeno total y pH. No se registra diferencia en las poblaciones de bacterias, pero sí de hongos en el período lluvioso. El rendimiento acumulado de café no difiere pero existe una tendencia en los sistemas agroecológicos al aumento. Los resultados sugieren que la implementación de prácticas agroecológicas contribuye de manera sustancial con la fertilidad global del suelo.La Calera Vol.14 No.23, 2014, pp.67-75

Biodiversity response to natural gradients of multiple stressors on continental margins.

Sharp increases in atmospheric CO2 are resulting in ocean warming, acidification and deoxygenation that threaten marine organisms on continental margins and their ecological functions and resulting ecosystem services. The relative influence of these stressors on biodiversity remains unclear, as well as the threshold levels for change and when secondary stressors become important. One strategy to interpret adaptation potential and predict future faunal change is to examine ecological shifts along natural gradients in the modern ocean. Here, we assess the explanatory power of temperature, oxygen and the carbonate system for macrofaunal diversity and evenness along continental upwelling margins using variance partitioning techniques. Oxygen levels have the strongest explanatory capacity for variation in species diversity. Sharp drops in diversity are seen as O2 levels decline through the 0.5-0.15 ml l(-1) (approx. 22-6 µM; approx. 21-5 matm) range, and as temperature increases through the 7-10°C range. pCO2 is the best explanatory variable in the Arabian Sea, but explains little of the variance in diversity in the eastern Pacific Ocean. By contrast, very little variation in evenness is explained by these three global change variables. The identification of sharp thresholds in ecological response are used here to predict areas of the seafloor where diversity is most at risk to future marine global change, noting that the existence of clear regional differences cautions against applying global thresholds.

Macrofaunal communities associated with chemosynthetic habitats from the U.S. Atlantic margin: A comparison among depth and habitat types

Hydrocarbon seeps support distinct benthic communities capable of tolerating extreme environmental conditions and utilizing reduced chemical compounds for nutrition. In recent years, several locations of methane seepage have been mapped along the U.S. Atlantic continental slope. In 2012 and 2013, two newly discovered seeps were investigated in this region: a shallow site near Baltimore Canyon (BCS, 366–412m) and a deep site near Norfolk Canyon (NCS, 1467–1602m), with both sites containing extensive chemosynthetic mussel bed and microbial mat habitats. Sediment push cores, suction samples, and Ekman box cores were collected to quantify the abundance, diversity, and community structure of benthic macrofauna (>300μm) in mussel beds, mats, and slope habitats at both sites. Community data from the deep site were also assessed in relation to the associated sediment environment (organic carbon and nitrogen, stable carbon and nitrogen isotopes, grain size, and depth). Infaunal assemblages and densities differed both between depths and among habitat types. Macrofaunal densities in microbial mats were four times greater than those present in mussel beds and slope sediments and were dominated by the annelid families Dorvilleidae, Capitellidae, and Tubificidae, while mussel habitats had higher proportions of crustaceans. Diversity was lower in BCS microbial mat habitats, but higher in mussel and slope sediments compared to NCS habitats. Multivariate statistical analysis revealed specific sediment properties as important for distinguishing the macrofaunal communities, including larger grain sizes present within NCS microbial mat habitats and depleted stable carbon isotopes (δ13C) in sediments present at mussel beds. These results suggest that habitat differences in the quality and source of organic matter are driving the observed patterns in the infaunal assemblages, including high β diversity and high variability in the macrofaunal community composition. This study is the first investigation of seep infauna along the U.S. Atlantic slope north of the Blake Ridge Diapir and provides a baseline for future regional comparisons to other seep habitats along the Atlantic margin.

Role of macrofauna on benthic oxygen consumption in sandy sediments of a high-energy tidal beach

Sandy beaches exposed to tide and waves are characterized by low abundance and diversity of benthic macrofauna, because of high-energy conditions. This is the reason why there are few studies on benthic communities living in such highly dynamic environments. It has been shown recently that tidal sandy beaches may act as biogeochemical reactors. Marine organic matter that is supplied in the sand during each flood tide is efficiently mineralized through aerobic respiration. In order to quantify the role of macrofauna in the whole beach benthic respiration, we studied the macrofauna and the pore water oxygen content of an exposed sandy beach (Truc Vert, SW of France) during four seasons in 2011. The results showed that macrofauna was characterised by a low number of species of specialized organisms such as the crustaceans Eurydice naylori and Gastrosaccus spp. and the polychaetes Ophelia bicornis and Scolelepis squamata. The distribution and abundance of macrofauna were clearly affected by exposure degree and emersion time. The combined monitoring of benthic macrofauna and pore waters chemistry allowed us to estimate (1) the macrofauna oxygen uptake, calculated with a standard allometric relationship using biomass data, and (2) the total benthic oxygen uptake, calculated from the oxygen deficit measured in pore waters. This revealed that benthic macrofauna respiration represented a variable but low (<10%) contribution to the total benthic oxygen consumption. This suggests that oxygen was mainly consumed by microbial respiration.

Soil Quality Indexing Strategies for Evaluating Sugarcane Expansion in Brazil.

Increasing demand for biofuel has intensified land-use change (LUC) for sugarcane (Saccharum officinarum) expansion in Brazil. Assessments of soil quality (SQ) response to this LUC are essential for quantifying and monitoring sustainability of sugarcane production over time. Since there is not a universal methodology for assessing SQ, we conducted a field-study at three sites within the largest sugarcane-producing region of Brazil to develop a SQ index (SQI). The most common LUC scenario (i.e., native vegetation to pasture to sugarcane) was evaluated using six SQI strategies with varying complexities. Thirty eight soil indicators were included in the total dataset. Two minimum datasets were selected: one using principal component analysis (7 indicators) and the other based on expert opinion (5 indicators). Non-linear scoring curves were used to interpret the indicator values. Weighted and non-weighted additive methods were used to combine individual indicator scores into an overall SQI. Long-term conversion from native vegetation to extensive pasture significantly decreased overall SQ. In contrast, conversion from pasture to sugarcane had no significant impact on overall SQ at the regional scale, but site-specific responses were found. In general, sugarcane production improved chemical attributes (i.e., higher macronutrient levels and lower soil acidity); however it has negative effects on physical and biological attributes (i.e., higher soil compaction and structural degradation as well as lower soil organic carbon (SOC), abundance and diversity of macrofauna and microbial activity). Overall, we found that simple, user-friendly strategies were as effective as more complex ones for identifying SQ changes. Therefore, as a protocol for SQ assessments in Brazilian sugarcane areas, we recommend using a small number of indicators (e.g., pH, P, K, Visual Evaluation of Soil Structure -VESS scores and SOC concentration) and proportional weighting to reflect chemical, physical and biological processes within the soil. Our SQ evaluations also suggest that current approaches for expanding Brazilian sugarcane production by converting degraded pasture land to cropland can be a sustainable strategy for meeting increasing biofuel demand. However, management practices that alleviate negative impacts on soil physical and biological indicators must be prioritized within sugarcane producing areas to prevent unintentional SQ degradation over time.

Variation in macrofaunal communities of sea grass beds along a pollution gradient in Bolinao, northwestern Philippines

This study examined the variation of macrofaunal communities in sea grass beds along a pollution gradient in Bolinao, northwestern Philippines. We established four stations and compared the diversity and abundance of macrofauna between them. The Shannon diversity index in the least polluted station was more than twice higher than that in the most polluted one. Abundance was more than thrice higher in the most polluted station. The species composition generally varied, with community difference explained largely by the predominance of the filter-feeding bivalve Gafrarium pectinatum and polychaete Capitella capitata. Species heterogeneity was reduced along the pollution gradient by approximately 19% from the least polluted to the most polluted station. This reduction indicates biodiversity alteration, which has a significant impact on ecosystem functioning. Aspects of species heterogeneity should be considered in environmental impact assessments and the management of coastal areas encountered with anthropogenic disturbances.

The Baltic Sea scale inventory of benthic faunal communities

AbstractThis study provides an inventory of the recent benthic macrofaunal communities in the entire Baltic Sea. The analyses of soft-bottom benthic invertebrate community data based on over 7000 locations in the Baltic Sea suggested the existence of 10 major communities based on species abundances and 17 communities based on species biomasses, respectively. The low-saline northern Baltic, characterized by silty sediments, is dominated by Monoporeia affinis, Marenzelleria spp., and Macoma balthica. Hydrobiidae, Pygospio elegans, and Cerastoderma glaucum dominate the community in sandy habitats off the Estonian west coast and in the southeastern and southern Baltic Sea. Deep parts of the Gulf of Finland and central Baltic Sea often experience hypoxia, and when oxygen levels in these regions recover, Bylgides sarsi was the first species to colonize. The southwestern Baltic Sea, with high salinity, has higher macrofaunal diversity compared with the northern parts. To spatially interpolate the distribution of the major communities, we used the Random Forest method. Substrate data, bathymetric maps, and modelled hydrographical fields were used as predictors. Model predictions were in good agreement with observations, quantified by Cohen's κ of 0.90 for the abundance and 0.89 in the wet weight-based model. Misclassifications were mainly associated with uncommon classes in regions with high spatial variability. Our analysis provides a detailed baseline map of the distribution of benthic communities in the Baltic Sea to be used both in science and management.

Abundance and Diversity of Soil Macrofauna in Native Forest, Eucalyptus Plantations, Perennial Pasture, Integrated Crop-Livestock, and No-Tillage Cropping

Intensive land use can affect macrofaunal biodiversity, which is a property that can be used as a soil quality indicator. This study evaluated the abundance and diversity of soil macrofauna and its relation to soil chemical and physical properties in five land use systems (LUS) in the eastern region of Santa Catarina. The following LUS were studied: native forest (NF), eucalyptus plantations (EP), perennial pasture (PP), integrated crop-livestock (ICL), and no-tillage cropping (NT). The macrofauna was quantified in 0.25 × 0.25 m monoliths and sampled in the 0.00-0.20 m layer in the summer (Jan/2012) and winter (Jul/2012). For each LUS, nine points were sampled, distributed in a 30 × 30 m sampling grid. After screening the edaphic macrofauna organisms, the individuals were counted and identified at the species level when possible, or in major taxonomic groups. The Shannon diversity indices were calculated and the macrofaunal groups together with the physical and chemical properties were subjected to principal component (PCA) and redundancy analysis (RDA). The abundance and diversity of macrofaunal groups are affected by the LUS. The properties of organic matter, macroporosity, bulk density, cation exchange capacity at pH 7.0, base saturation, potential acidity, and exchangeable Al were related to the abundance of soil macrofaunal groups. The stability and biodiversity of soil macrofauna were highest in the LUS of NF, PP, and EP.

五大连池药泉山大型土壤动物对旅游踩踏的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 五大连池药泉山大型土壤动物对旅游踩踏的响应 DOI: 10.5846/stxb201603230518 作者: 作者单位: 哈尔滨师范大学;黑龙江大学,哈尔滨师范大学,黑龙江大学,北京林业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41101048） Responses of soil macrofaunal communities to tourism trample in the Wudalianchi Yaoquan Mountains Author: Affiliation: Harbin Normal University;Heilongjiang University,Harbin Normal University,Heilongjiang University,Beijing Forestry University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以黑龙江省五大连池世界地质公园的药泉山为研究对象，按照距离游道的远近分为重度踩踏区，轻度踩踏区和非踩踏区3种踩踏干扰强度，分析大型土壤动物数量，群落组成，多样性对旅游踩踏干扰的响应。研究结果表明不同干扰区之间大型土壤动物类群数量差异显著（P<0.001），重度踩踏区显著低于轻度踩踏区和非踩踏区。不同干扰区大型土壤动物个体数差异明显（P<0.001），其中轻度踩踏区个体密度最大（68头/m2），重度踩踏区个体密度最小（10头/m2）。不同踩踏强度干扰区H’指数差异明显（P<0.05），轻度踩踏区及非踩踏区的多样性显著高于严重踩踏区。典型对应分析表明旅游踩踏主要通过改变土壤理化特性而影响大型土壤动物的组成及其多样性，重度踩踏区、轻度踩踏区和非踩踏区对大型土壤动物影响最显著的因子分别为土壤全氮含量，土壤含水率和土壤全磷含量。 Abstract:Trampling is widespread among various recreational activities, and this can become a significant problem as it represents a major disturbance affecting the vegetation and soil surface horizon. Soil macrofauna, mainly in the soil surface horizon, are good indicators for studying the impact of human activities. In the present study, Yaoquan Mountain of Wudalianchi World Geo-park was considered as a study example in 2012. The areas surrounding tourism trails were divided into no-trampling, mid-trampling, and high-trampling plots, which were divided based on three different interference types. The effect of human trampling on soil macrofaunal communities at a depth of 0-10 cm were studied along an increasing distance from the tourism trail of Yaoquan Mountain. A completely randomized design, including three replicates from three trampling interference sites, was used. Soil macrofauna were separated by hand, and were identified and counted. Soil bulk density, soil moisture content, soil organic matter content, total nitrogen content, and total phosphorus content were measured from each site. Our study evaluated the structure, composition, diversity, and distribution of soil macrofauna in three different tourism trample types, and assessed the impacts of human activity. The results were summarized as the following aspects:The total number of soil animal genera was significantly different in the three disturbance degree sites (P<0.001) and the least number of genera occurred in high trampling sites. The individual density of soil macrofauna was significantly different from the other kinds of soil animal fauna in the three disturbance degree sites (P<0.001), the maximum value was in the mid-trampling plots (68 ind./m2), and the minimum value was in the high-trampling sites (10 ind./m2). The Shannon index (H') of soil micro-fauna were seriously affected by trampling (P<0.05), and the high trampling sites had the lowest H' index. A canonical correspondence analysis indicated the soil macrofaunal distribution in the mid-trampling and high-trampling plots differed from the no-trampling plots. The main factor affecting soil macrofauna distribution was soil total nitrogen content, soil moisture content, and total phosphorus content in no-trampling, mid-trampling, and high-trampling plots, respectively. 参考文献 相似文献 引证文献

Spatial analysis of riparian forest soil macrofauna and its relation to abiotic soil properties

Soil macrofauna play major roles in ecosystem functioning; however the ecological effects of macrofauna are influenced by their spatial distribution. Close relationships to soil properties are one major factor for determining spatial pattern of macrofauna. Information about macrofauna distribution pattern is scarce especially at regional scales. The limited numbers of studies available suggest a considerable influence of soil properties on macrofauna distribution. Therefore, this study was conducted in riparian forest to elucidate spatial patterns of soil macrofauna and their relationship to abiotic soil properties at regional scale. Soil macrofauna abundance, diversity, richness and evenness were analyzed at 200 sampling points along parallel transects which ran perpendicular to a river. The hierarchical sampling design comprised maximum distances of 0.5km and minimum distances of 1m between samples. Soil macrofauna was extracted from 50cm×50cm×25cm soil monoliths by hand-sorting. At each transect point additional soil samples were taken for analysis of soil texture, standard soil properties and electrolytic conductivity. Data were analyzed using geostatistics (variograms and cross-variograms) in order to describe and quantify the spatial continuity of macrofauna characteristics and their relation to soil properties. The variograms revealed the presence of spatial autocorrelation in the majority of parameters. Also, relationships between macrofauna and soil properties such as soil texture and electrolytic conductivity, could be detected. To get more information about macrofauna distribution patterns and macrofauna–soil-relationships, subsets of the complete dataset were analyzed by means of applied time series analysis. The basic pattern of diversity value along the spatial series could be estimated by an autoregressive model. In addition, state-space analysis revealed that soil texture (silt) was important for estimating soil macrofauna diversity along transects. The study shows that geostatistical analyses as well as applied time series are suitable methods for analyzing macrofauna characteristics and for detecting relationships to soil properties. In contrast to geostatistics, state-space analysis yields additional information about the relative importance of different parameters for estimating macrofauna characteristics.

The Bostrychietum community of pneumatophores in Araçá Bay: an analysis of the diversity of macrofauna

A mangrove forest can harbour several macroalgal assemblages growing on pneumatophores, roots, stems and other hard substrates. These algae belong to various genera, most typicallyBostrychia, and form a community called the Bostrychietum. This study describes the fauna associated with the Bostrychietum and the effect of emersion time on the community. Seasonal samples were collected from pneumatophores on an island in Araçá Bay in 2012, in two areas, one on the border of the island and one inland. Each pneumatophore was considered a sample. The border samples, with a shorter emersion time, contained a richer algal flora associated with pneumatophores, and fauna with species of varied dietary habits. The inland samples, with a longer emersion time, contained only two algal genera and fauna species comprised mostly of omnivorous amphipods and desiccation-resistant detritivorous species. Macrofauna diversity and richness varied over time and were lower in spring. Therefore, the emersion time of the Bostrychietum and the period of the year affect the community structure, for both the macroalgae and the associated fauna.

The Community Structures of Prokaryotes and Fungi in Mountain Pasture Soils are Highly Correlated and Primarily Influenced by pH

Traditionally, conservation and management of mountain pastures has been managed solely on the basis of visible biota. However, microorganisms play a vital role for the functioning of the soil ecosystem and, hence, pasture sustainability. Here, we studied the links between soil microbial (belowground) community structure (using amplicon sequencing of prokaryotes and fungi), other soil physicochemical and biological properties and, finally, a variety of pasture management practices. To this aim, during two consecutive years, we studied 104 environmental sites characterized by contrasting elevation, habitats, bedrock, and pasture management; located in or near Gorbeia Natural Park (Basque Country/Spain). Soil pH was found to be one of the most important factors in structuring soil microbial diversity. Interestingly, we observed a striking correlation between prokaryotic, fungal and macrofauna diversity, likely caused by interactions between these life forms. Further studies are needed to better understand such interactions and target the influence of different management practices on the soil microbial community, in face of the significant heterogeneity present. However, clearing of bushes altered microbial community structure, and in sites with calcareous bedrock also the use of herbicide vs. mechanical clearing of ferns.

Depth-related spatial patterns of sublittoral blue mussel beds and their associated macrofaunal diversity revealed by geostatistical analyses

The blue mussel Mytilus edulis is a foundation species with ecosystem engineering functions in the brackish, non-tidal Baltic Sea. In this study from the western Gulf of Finland, the relationship between the spatial patchiness of blue mussels and the diversity of associated macrofauna was examined across small scales (centimeters to meters) for the first time in subtidal habitats. It was demonstrated using geostatistical tools that blue mussel abundance and the diversity of associated macrofauna varied and interacted at 2 depths. Classic analyses (ANOVAs, correlations and multivariate techniques) detected no relationships between the abundance of blue mussels and their associated macrofaunal diversity, or differences in the abundance of mussels or the diversity of associated macrofauna between depths. Using semivariograms, differences in spatial heterogeneity between depths emerged: i.e. patchiness at 5 m and random patterns at 8 m depth. Cross-semivariograms detected negative spatial co-variation between blue mussel abundance and diversity of macrofauna at 5 m, but positive and neutral spatial relationships at 8 m depth. Combining the approaches suggested that high dislodgment of mussels in shallow environments causes this pattern. Dislodgement effects may be compensated for by increased turnover of small mussels in patches within mussel beds, which would result in reduced habitat space for associated macrofauna. On the basis of our results, it is suggested that patchiness of a foundation species is an ecological response, or result of a disturbance, that reduces the diversity of the associated macrofaunal community.

Phosphorus pools responses to land-use change for sugarcane expansion in weathered Brazilian soils

Without proper management, land-use change (LUC) associated with producing sugarcane (Saccharum officinarum) for bioenergy in Brazil can lead to soil degradation and have negative implications on ecosystem functions. Phosphorus (P) depletion is one of the most frequent causes of land degradation in tropical environments, and as such, soil P pools have been identified as potential indicators of negative environmental impacts. We quantified soil P dynamics for the most common LUC sequence in sugarcane expansion areas [i.e., native vegetation (NV) to pasture (PA) to sugarcane (SC)], to determine if and how these changes could be used to evaluate environmental impacts of LUC in weathered Brazilian soils. Soil samples were collected from three areas in central-southern Brazil, representing the primary sugarcane-producing region of the world. Soil P fractionation was performed, and P stocks were calculated for the surface 30cm. Soil chemical attributes and macrofauna data were correlated with P pools. Long-term conversions from natural ecosystems (Cerrado and Atlantic forest biome) to extensive PA decreased total P stocks by 31.2% indicating progressive soil degradation in these areas. In contrast, the LUC from PA to SC increased total P stocks by 35.6%; nevertheless, fertilization management altered the soil P-cycle, causing P accumulation in less plant-available forms. Available P increases to support adequate SC growth are still needed. Applying P using organic residues increased labile organic P and may be a complementary strategy for increasing nutrient supplies in SC fields. Phosphorus availability showed significant positive correlations with other soil chemical properties and clay content, while the functional diversity of soil macrofauna was strongly correlated with labile and biological P. We conclude that P pools can be useful indicators for assessing LUC modifications on soil quality in the tropics, and recommend they be used to assess land degradation and environmental sustainability within SC expansion areas in Brazil.