Soil nematode abundance and functional group composition at a global scale.

Soil organisms are a crucial part of the terrestrial biosphere. Despite their importance for ecosystem functioning, few quantitative, spatially explicit models of the active belowground community currently exist. In particular, nematodes are the most abundant animals on Earth, filling all trophic levels in the soil food web. Here we use 6,759 georeferenced samples to generate a mechanistic understanding of the patterns of the global abundance of nematodes in the soil and the composition of their functional groups. The resulting maps show that 4.4 ± 0.64 × 1020 nematodes (with a total biomass of approximately 0.3 gigatonnes) inhabit surface soils across the world, with higher abundances in sub-Arctic regions (38% of total) than in temperate (24%) or tropical (21%) regions. Regional variations in these global trends also provide insights into local patterns of soil fertility and functioning. These high-resolution models provide the first steps towards representing soil ecological processes in global biogeochemical models and will enable the prediction of elemental cycling under current and future climate scenarios.

Cd and Pb bioaccumulation in Eurasian watermilfoil (Myriophyllum spicatum) in relation to the role of metal contents in wetland sediments.

The Choghakhor Wetland in Chaharmahal and Bakhtiari Province (Iran) has a significant role in maintaining water and sediment quality, because the wetland acts as a sink for contaminants that can pollute the aquatic ecosystem and affect human health. The present study uses a simple geostatistical technique to investigate the spatial variability of Cd and Pb in the Choghakhor Wetland to link the spatial variations of sediments to heavy metal contents in Myriophyllum spicatum. It was hypothesized that the heavy metal contents in the Choghakhor Wetland sediments impacted the concentration values in macrophytes. The value of heavy metals in sediments ranges from 0.54- to 1.84-µg/g dry weight (dw) for Cd, and from 1.32- to 2.46-µg/g dw for Pb, with a mean value of 1.12- and 1.82-µg/g dw, respectively. The mean value of Cd and Pb was 1.14- and 1.67-µg/g dw, respectively, in the aquatic macrophyte Myriophyllum spicatum, with corresponding ranges of 0.9-1.83-µg/g dw and 1.33-1.95-µg/g dw. There was a spatial structure in the Cd and Pb contents in the wetland sediments, with lower contents in the northern zone despite the values quantified in the south. We observed a direct spatial relationship between the Cd content in sediments and the Cd concentration in M. spicatum, and confirmed an effect of plant uptake for Cd. However, there were no significant differences between Pb in sediments and Pb in samples of M. spicatum, which implied that other factors like discharged industrial waste could also affect the accumulation of metals in plants. It can be concluded that spatial patterns indicated differences in the territory of the sediment Cd content at the Choghakhor Wetland localization in association with sediment enrichment. However, it was surprising that Pb did not show this pattern despite anthropic pressure.

Potentially toxic element bioaccumulation in consumed indoor shrimp farming associated with diet, water and sediment levels.

Shrimp production is an important industry for many countries and shrimp consumption is increasing worldwide. Shrimps are a highly nutritional food, but can pose a risk for human health if subject to high levels of environmental contaminants. This work studies the presence of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in shrimps from Ecuador and compares them to such contents noted in other shrimp-production areas in the world to evaluate the possible risks associated with these elements for consumer health, and to relate them to potentially toxic element (PTE) contents in water, sediments and diets, and also to animal biometric parameters. The PTE levels (mg kg-1 DM) obtained are as follows: in the head-As (3.52-6.11), Cd (0.02-0.10), Co (0.14-0.49) Cr (0.23-4.89), Cu (99.9--233.0), Ni (0.52-1.86), Pb (0.24-1.09), Zn (51.8-100.5) and Hg (µg kg-1 DM) (10.00-66.81); in the tail-(0.91-3.21), Cd (0.01-0.02), Co (0.01-0.43) Cr (0.01-6.52), Cu (20.0-72.44), Ni (0.15-2.03), Pb (0.01-0.69), Zn (31.2-66.1) and Hg (µg kg-1 DM) (10.00-67.18). The concentration of all the PTEs is generally lower than the limits set for seafood by European regulations, except for As in the cephalothorax (4.63 mg kg-1). Different behaviours for PTE accumulation in shrimps were found, which preferentially tend to accumulate in the cephalothorax, except for Hg (40.13 µg kg-1 DM), which accumulates in muscle (body) and is associated with contents of proteins, lipids and total shrimp weight. Nonetheless, the target hazard quotient (THQ) values for PTEs indicate that the consumption of shrimp muscles from Ecuador does not pose a human health risk because the values of these indices are below 1 in all cases.

Human Rights in the Least Developed Countries of Asia: An Index for Quantifying Sustainable Development Goal 3 (Good Health and Wellbeing).

This paper aims to measure disparities among the variables associated with Sustainable Development Goal (SDG) 3 defined by the United Nations (UN) in the least developed countries (LDCs) of Asia. In the terms of the UN Conference on Trade and Development, LDCs are countries with profound economic and social inequalities. The indicator was constructed using a set of variables associated with SDG3: Good Health and Wellbeing. Applying Pena's DP2 distance method to the most recent data available (2018) enables regional ordering of Asia's LDCs based on the values of these variables. The index integrates socioeconomic variables that permit examination of the impact of each individual indicator to determine territorial disparities in terms of the partial indicators of SDG3. "Maternal education," "Proportion of women who make their own informed decisions regarding sexual relations, contraceptive use, and reproductive health care," and "Gender parity index in primary education" are the most important variables in explaining spatial disparities in good health and wellbeing in the LDCs of Asia.

A global database of soil nematode abundance and functional group composition.

As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns.

Effects of Vacation Rental Websites on the Concentration of Tourists-Potential Environmental Impacts. An Application to the Balearic Islands in Spain.

The concentration of tourists at certain times of the year can damage sensitive environments. The use of peer-to-peer vacation rental websites has increased greatly during the last decade. This system could either reduce seasonality in touristic destinations where the tourist activity takes place throughout the year at a lower price or on the contrary, it could increase the number of visitors at certain times of the year even more. This paper intends to analyze the effect that these platforms have on tourism seasonality in order to calculate if they help reduce or increase the pressure on the destinations. To do so, the Gini Index has been applied to one of the main touristic spots in Europe, the Balearic Islands in Spain. The conclusion is that this type of accommodation has aggravated the problem, generating a greater concentration of tourists and a higher pressure on the resources of the islands.