Seasonal Variations Affect The Ecosystem Functioning And Microbial Assembly Processes In Plantation Forests

Background: While afforestation mitigates climate concerns, the impact of afforestation on soil microbial compositions, ecological assembly processes, and multiple soil functions (multifunctionality) in afforested areas remains unclear. The Xiong'an New Area plantation forests (Pinus and Sophora forests) were selected to examine the effects of plantation types in four contrasting seasons on soil microbiomes.Results: We evaluated three functional categories (nutrient stocks, organic matter decomposition, and microbial functional genes) of multifunctionality, and the average (net) multifunctionality was quantified. The results showed that net soil multifunctionality as a broad function did not change seasonally, unlike other narrow functional categories. Bacterial communities were deterministically (variable selection and homogenous selection) structured, whereas the stochastic process of dispersal limitation was mainly responsible for the assembly and turnover of fungal and protist communities. Additionally, we showed that winter triggered an abrupt transition in the bacterial community assembly from deterministic to stochastic processes in Pinus forests that was closely associated with a reduction in the bacterial Shannon diversity, with functional patterns of a high level of nutrient cycling (nutrient stocks and organic matter decomposition). Conclusions: Overall, the present study contributes local-ecosystem prospects to model the behavior of soil biota seasonally and their implied effects on soil functioning and microbial assembly processes in plantation forests.

The effects of sealing on urban soil carbon and nutrients

Urban soils are of increasing interest for their potential to provide ecosystem services such as carbon storage and nutrient cycling. Despite this, there is limited knowledge on how soil sealing with impervious surfaces, a common disturbance in urban environments, affects these important ecosystem services. In this paper, we investigate the effect of soil sealing on soil properties, soil carbon and soil nutrient stocks. We undertook a comparative survey of sealed and unsealed green space soils across the UK city of Manchester. Our results reveal that the context of urban soil and the anthropogenic artefacts added to soil have a great influence on soil properties and functions. In general, sealing reduced soil carbon and nutrient stocks compared to green space soil; however, where there were anthropogenic additions of organic and mineral artefacts, this led to increases in soil carbon and nitrate content. Anthropogenic additions led to carbon stocks equivalent to or larger than those in green spaces; this was likely a result of charcoal additions, leading to carbon stores with long residence times. This suggests that in areas with an industrial past, anthropogenic additions can lead to a legacy carbon store in urban soil and make important contributions to urban soil carbon budgets. These findings shed light on the heterogeneity of urban sealed soil and the influence of anthropogenic artefacts on soil functions. Our research highlights the need to gain a further understanding of urban soil processes, in both sealed and unsealed soils, and of the influence and legacy of anthropogenic additions for soil functions and important ecosystem services.

Effects of Long-Term Enclosing on Vertical Distributions of Soil Physical Properties and Nutrient Stocks in Grassland of Inner Mongolia

Enclosing plays a crucial role in vegetation and soil quality in grassland. The biomass of green plants, litter, and vertical distributions of soil physical properties and nutrient stocks were evaluated at plot enclosed long term for 38 years inside a fence and a long-term grazing plot outside a fence in a semi-arid grassland of Inner Mongolia. The results showed that dry matter of green plants and litter during the 38-year enclosing treatment was higher than in the grazing treatment (p < 0.01). The soil silt (2–50 μm) in the 38-year enclosing treatment was 5.9% higher than in the grazing treatment (p < 0.01) in 0–10 cm soil, and the fine sand (100–250 μm) was 6.0% lower (p < 0.05). The 38-year enclosing treatment slightly decreased the bulk density and significantly decreased the electrical conductivity in each soil layer (0–100 cm). The 38-year enclosing treatment significantly increased the stocks of soil organic carbon (SOC), available phosphorus (AP), and available potassium (AK) on the surface soil, and obviously decreased the stocks of total nitrogen (TN), total phosphorus (TP), calcium (Ca), magnesium (Mg), sulfur (S), and available nitrogen (AN) in each soil layer (0–100 cm). In conclusion, long-term enclosing improved grassland production, but decreased most nutrient stocks in soil.

The effects of sealing on urban soil carbon and nutrients

Urban soils are of increasing interest for their potential to provide ecosystem services such as carbon storage and nutrient cycling. Despite this, there is limited knowledge on how soil sealing with impervious surfaces, a common disturbance in urban environments, affects these important ecosystem services. In this paper, we investigate the effect of soil sealing on soil properties, soil carbon and soil nutrient stocks. We undertook a comparative survey of sealed and unsealed greenspace soils across the UK city of Manchester. Our results reveal that the context of urban soil and the anthropogenic artefacts added to soil have a great influence on soil properties and functions. In general, sealing reduced soil carbon and nutrient stocks compared to greenspace soil, however, where there were anthropogenic additions of organic and mineral artefacts this led to increases in soil carbon and nitrate content. Anthropogenic additions led to carbon stocks equivalent to or larger than those in greenspaces, potentially of a stable nature with long residence times. This suggests that in areas with an industrial past, anthropogenic additions can lead to a legacy carbon store in urban soil and make important contributions to urban soil carbon budgets. These findings shed light on the heterogeneity of urban sealed soil and the influence of anthropogenic artefacts on soil functions. Our research highlights the need to gain further understanding into urban soil processes, in both sealed and unsealed soils, and the influence and legacy of anthropogenic additions on soil functions and important ecosystem services.

Parameters influencing green roof carbon and nutrient stocks

&lt;p&gt;Increasing urbanization brings along problems such as elevated CO&lt;sub&gt;2&lt;/sub&gt; emissions, eutrophication, air and water pollution, floods, rising temperature and a decrease in biodiversity. Urban green infrastructures, such as green roofs, have the potential to help mitigate those by using the properties of natural ecosystems and the services they provide in a &amp;#8220;engineered&amp;#8221; way. Green roofs can for example act as buffers and filters for carbon (C), nutrients, such as nitrogen (N) and phosphorus (P), and water. Hereby improving CO&lt;sub&gt;2 &lt;/sub&gt;concentrations in the atmosphere by capturing it in plant biomass and improving eutrophication by retaining some dissolved organic carbon (DOC) and mineral N and P in the substrate.&lt;/p&gt;&lt;p&gt;In this research we determine which green roof properties affect the C, N and P cycle in a beneficial way. Therefore, we investigate the influence of different parameters (i.e. roof age, roof size, vegetation type (&lt;em&gt;Sedum&lt;/em&gt; and herbs vs. &lt;em&gt;Sedum&lt;/em&gt;-only), fertilization, substrate depth, substrate water content, substrate bulk density, substrate pH, plant biomass, plant C/N ratio, N mineralization and nitrification) on the C and nutrient stocks of green roofs. We hypothesize that vegetation type and roof age will be the main factors influencing the C and nutrient stocks. A roof with &lt;em&gt;Sedum&lt;/em&gt; and herbs will have a higher nutrient and C input resulting in higher stocks compared to a &lt;em&gt;Sedum&lt;/em&gt;-only roof because herbs have a higher turn-over rate compared to &lt;em&gt;Sedum&lt;/em&gt;-species. Furthermore, older roofs will stock more C. In the beginning C will be mainly sequestered in plant biomass until the roof is densely covered. Here after, green roofs will be able to build up an organic matter layer if the net primary production exceeds decomposition.&lt;/p&gt;&lt;p&gt;To assess the influence of these parameters on the C, N and P stocks, twelve extensive green roofs were investigated in Belgium. The substrate and vegetation of every roof was sampled at four timepoints (spring, summer and autumn of 2019, winter 2020). Substrate samples were analyzed for stocks (total C, total N, total P) along with other abiotic soil parameters as well as some key soil processes (N mineralization and relative nitrification) for soil fertility.&lt;/p&gt;&lt;p&gt;Our first findings show, as expected, that roofs with &lt;em&gt;Sedum&lt;/em&gt; and herbs have an increased total C, N and P in their substrate. In addition, C and P stocks are significantly influenced by roof age: while P stocks slightly decrease over time, C stocks only increased transiently &amp;#8212;against our predictions&amp;#8212;, with a peak at around 9 years old.&lt;/p&gt;

Nutrient Stocks and Distribution in Ghanaian Cocoa Ecosystems

There is a paucity of information on nutrient stocks and distribution in the cocoa ecosystem for the management of production sites to improve its productivity. Apart, sites with long histories of cocoa production could differ in nutrient stocks and distribution relative to recent production regions. Therefore, some existing cocoa farms in Ghana were sampled on the basis of shade management (shaded and unshaded) and production site longevity (Eastern region > Western North region) to determine the nutrient stock and distributions in them. Over 93% of the total ecosystems’ elementary nutrients were stored in the soil. Higher nutrient stocks occurred under shaded cocoa ecosystem. Nutrient element concentrations in cocoa tree biomasses followed the order: N > Ca > K > Mg > P > S > Al = Fe > Zn = Mn, and mostly concentrated in leaf > root = husk > branch > stem. On average, region as a main factor affected nutrient distributions. There was a sharp distinction between macronutrient and micronutrient accumulations in favour of Eastern region and Western North region, respectively. Therefore, the regional distinction with respect to macro- and micronutrients could be used as a guide to fertilizer recommendation for cocoa systems in the two regions.