Herbaceous vegetation under temperate climatic conditions generally shows nitrogen- or phosphorus-limited plant growth, which creates conditions for a high botanical diversity. Is nitrogen (N) or phosphorus (P) the most important limiting factor, or are both generally in short supply? What are the consequences of Increased N and P inputs that result from anthropogenic disturbances? A new indicator of N or P limitation, that is, the vegetation N:P ratio, allows us to address these questions for a range of mires, dune slacks and moist grasslands.

Nitrogen-or phosphorus-limited growth in herbaceous, wet vegetation : relations with atmospheric input and management regimes

China?s aquaculture industry accounts for the largest share of the world?s fishery production, and provides a principal source of protein for the nation?s booming population. However, the environmental effects of the nutrient loadings produced by this industry have not been systematically studied or reviewed. Few quantitative estimates exist for nutrient discharge from aquaculture and the resultant nutrient enrichment in waters and sediments. In this paper, we evaluate nutrient discharge from aquacultural systems into aquatic ecosystems and the resulting nutrient enrichment of water and sediments, based on data from 330 cases in 51 peer-reviewed publications. Nitrogen use efficiency ranged from 11.7% to 27.7%, whereas phosphorus use efficiency ranged from 8.7% to 21.2%. In 2010, aquacultural nutrient discharges into Chinese aquatic ecosystems included 1044 Gg total nitrogen (184 Gg N from mariculture; 860 Gg N freshwater culture) and 173 Gg total phosphorus (22 Gg P from mariculture; 151 Gg P from freshwater culture). Water bodies and sediments showed high levels of nutrient enrichment, especially in closed pond systems. However, this does not mean that open aquacultural systems have smaller nutrient losses. Improvement of feed efficiency in cage systems and retention of nutrients in closed systems will therefore be necessary. Strategies to increase nutrient recycling, such as integrated multi-trophic aquaculture, and social measures, such as subsidies, should be increased in the future. We recommend the recycling of nutrients in water and sediments by hybrid agricultural-aquacultural systems and the adoption of nutrient use efficiency as an indicator at farm or regional level for the sustainable development of aquaculture; such indicators; together with water quality indicators, can be used to guide evaluations of technological, policy, and economic approaches to improve the sustainability of Chinese aquaculture.

https://iopscience.iop.org/article/10.1088/1748-9326/10/4/045002/pdf

Nutrient discharge from China’s aquaculture industry and associated environmental impacts

Aquatic macrophytes, often also called hydrophytes, are key components of aquatic and wetland ecosystems. This review is to briefly summarizes various macrophyte classifications, and covers numerous aspects of macrophytes` role in wetland ecosystems, namely in nutrient cycling. The most widely accepted macrophyte classification differentiates between freely floating macrophytes and those attached to the substrate, with the attached, or rooted macrophytes further divided into three categories: floating-leaved, submerged and emergent. Biogeochemical processes in the water column and sediments are to a large extent influenced by the type of macrophytes. Macrophytes vary in their biomass production, capability to recycle nutrients, and impacts on the rhizosphere by release of oxygen and organic carbon, as well as their capability to serve as a conduit for methane. With increasing eutrophication, the species diversity of wetland macrophytes generally declines, and the speciose communities are being replaced by monoculture-forming strong competitors. A similar situation often happens with invasive species. The roles of macrophytes and sediment microorganisms in wetland ecosystems are closely connected and should be studied simultaneously rather than in isolation.

The role of macrophytes in wetland ecosystems

Summary
1).Increasing rates of permafrost thaw in boreal peatlands are converting conifer forests to waterlogged open wetlands. Permafrost thaw increases soil nitrogen (N) availability, but it is unclear whether such changes are due solely to changes in surface soil N mineralization or N mobilization from thawing permafrost soils at depth.

2).We examined plant species composition and N availability along triplicate permafrost thaw gradients in Alaskan peatlands. Each gradient comprised four community types including: 1) a permafrost peatland with intact permafrost; 2) a drunken forest experiencing active thaw; 3) a moat representing initial complete thaw; and 4) a collapse scar bog representing several decades of post-thaw succession.

3).Concentrations of dissolved organic (DON) and inorganic N (DIN) in the upper 60 cm of soil increased along the permafrost thaw gradients. The drunken forest had the greatest mean concentrations of total dissolved N relative to the other community types, primarily due to greater concentrations of large molecular DON. The moat and collapse bog had significantly greater inorganic N concentrations than the permafrost or drunken forest, suggesting that changes in N availability are not a short-term effect, but can be sustained for decades or centuries. Across all plant community types, DIN and DON concentrations increased with soil depth during maximum seasonal ice thaw (September), suggesting that deeper soil horizons are important reservoirs of N post-thaw.

4).Vegetation responses to permafrost thaw included changes in plant community composition shifting from upland forest species to hydrophilic vegetation with deeper rooting profiles in the collapse scar bogs, and changes in foliar N and δ15N values. N concentrations in plant foliage and litterfall increased with concentrations of DIN during collapse bog succession, suggesting that plants are utilizing additional mineralized N.

5).Synthesis: Our results suggest that the conversion of forest to wetlands associated with permafrost thaw in boreal lowlands increases N availability, at least in part by increasing turnover of deep soil organic matter. Plants appear to utilize these additional deeper N sources over timescales of years to centuries following permafrost thaw.

This article is protected by copyright. All rights reserved.

https://besjournals.onlinelibrary.wiley.com/doi/epdf/10.1111/1365-2745.12639

Effects of permafrost thaw on nitrogen availability and plant–soil interactions in a boreal Alaskan lowland

Coexistence of multiple leaf nutrient resorption strategies in a single ecosystem.

N:P ratios, δ15N fractionation and nutrient resorption along a nitrogen to phosphorus limitation gradient in an oligotrophic wetland complex

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Les M. Basher

Author Tools

Chat about Author

Papers

N:P ratios, δ15N fractionation and nutrient resorption along a nitrogen to phosphorus limitation gradient in an oligotrophic wetland complex