{"type": "FeatureCollection", "features": [{"id": "10.1007/s00248-003-9001-x", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:14:41Z", "type": "Journal Article", "created": "2004-06-15", "title": "Microbial Community Structure And Oxidative Enzyme Activity In Nitrogen-Amended North Temperate Forest Soils", "description": "Large regions of temperate forest are subject to elevated atmospheric nitrogen (N) deposition which can affect soil organic matter dynamics by altering mass loss rates, soil respiration, and dissolved organic matter production. At present there is no general model that links these responses to changes in the organization and operation of microbial decomposer communities. Toward that end, we studied the response of litter and soil microbial communities to high levels of N amendment (30 and 80 kg ha(-1) yr(-1)) in three types of northern temperate forest: sugar maple/basswood (SMBW), sugar maple/red oak (SMRO), and white oak/black oak (WOBO). We measured the activity of extracellular enzymes (EEA) involved directly in the oxidation of lignin and humus (phenol oxidase, peroxidase), and indirectly, through the production of hydrogen peroxide (glucose oxidase, glyoxal oxidase). Community composition was analyzed by extracting and quantifying phospholipid fatty acids (PLFA) from soils. Litter EEA responses at SMBW sites diverged from those at oak-bearing sites (SMRO, BOWO), but the changes were not statistically significant. For soil, EEA responses were consistent across forests types: phenol oxidase and peroxidase activities declined as a function of N dose (33-73% and 5-41%, respectively, depending on forest type); glucose oxidase and glyoxal oxidase activities increased (200-400% and 150-300%, respectively, depending on forest type). Principal component analysis (PCA) ordinated forest types and treatment responses along two axes; factor 1 (44% of variance) was associated with phenol oxidase and peroxidase activities, factor 2 (31%) with glucose oxidase. Microbial biomass did not respond to N treatment, but nine of the 23 PLFA that formed >1 mol% of total biomass showed statistically significant treatment responses. PCA ordinated forest types and treatment responses along three axes (36%, 26%, 12% of variance). EEA factors 1 and 2 correlated negatively with PLFA factor 1 ( r = -0.20 and -0.35, respectively, n = 108) and positively with PLFA factor 3 ( r = +0.36 and +0.20, respectively, n = 108). In general, EEA responses were more strongly tied to changes in bacterial PLFA than to changes in fungal PLFA. Collectively, our data suggests that N inhibition of oxidative activity involves more than the repression of ligninase expression by white-rot basidiomycetes.", "keywords": ["Michigan", "Nitrogen", "Science", "Ecology and Evolutionary Biology", "Nature Conservation", "Microbiology", "Trees", "Soil", "Geoecology/Natural Processes", "Health Sciences", "Cellular and Developmental Biology", "Ecosystem", "Phospholipids", "Soil Microbiology", "2. Zero hunger", "Analysis of Variance", "Principal Component Analysis", "Ecology", "Life Sciences", "Natural Resources and Environment", "Molecular", "04 agricultural and veterinary sciences", "15. Life on land", "Enzymes", "13. Climate action", "0401 agriculture", " forestry", " and fisheries"]}, "links": [{"href": "https://doi.org/10.1007/s00248-003-9001-x"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Microbial%20Ecology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s00248-003-9001-x", "name": "item", "description": "10.1007/s00248-003-9001-x", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s00248-003-9001-x"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2004-04-19T00:00:00Z"}}, {"id": "10.1007/s10021-005-0085-7", "type": "Feature", "geometry": null, "properties": {"updated": "2026-07-25T16:14:53Z", "type": "Journal Article", "created": "2006-03-20", "title": "Microbial Cycling Of C And N In Northern Hardwood Forests Receiving Chronic Atmospheric No3- Deposition", "description": "Sugar maple (Acer saccharum Marsh.)-dominated northern hardwood forests in the upper Lakes States region appear to be particularly sensitive to chronic atmospheric NO                   3                   \u2212                  deposition. Experimental NO                   3                   \u2212                  deposition (3 g NO                   3                   \u2212                  N m\u22122 y\u22121) has significantly reduced soil respiration and increased the export of DOC/DON and NO                   3                   \u2212                  across the region. Here, we evaluate the possibility that diminished microbial activity in mineral soil was responsible for these ecosystem-level responses to NO                   3                   \u2212                  deposition. To test this alternative, we measured microbial biomass, respiration, and N transformations in the mineral soil of four northern hardwood stands that have received 9 years of experimental NO                   3                   \u2212                  deposition. Microbial biomass, microbial respiration, and daily rates of gross and net N transformations were not changed by NO                   3                   \u2212                  deposition. We also observed no effect of NO                   3                   \u2212                  deposition on annual rates of net N mineralization. However, NO                   3                   \u2212                  deposition significantly increased (27%) annual net nitrification, a response that resulted from rapid microbial NO                   3                   \u2212                  assimilation, the subsequent turnover of NH                   4                   +                 , and increased substrate availability for this process. Nonetheless, greater rates of net nitrification were insufficient to produce the 10-fold observed increase in NO                   3                   \u2212                  export, suggesting that much of the exported NO                   3                   \u2212                  resulted directly from the NO                   3                   \u2212                  deposition treatment. Results suggest that declines in soil respiration and increases in DOC/DON export cannot be attributed to NO                   3                   \u2212                 -induced physiological changes in mineral soil microbial activity. Given the lack of response we have observed in mineral soil, our results point to the potential importance of microbial communities in forest floor, including both saprotrophs and mycorrhizae, in mediating ecosystem-level responses to chronic NO                   3                   \u2212                  deposition in Lake States northern hardwood forests.", "keywords": ["0106 biological sciences", "Ecology", "Science", "Plant Sciences", "Soil C and N Cycling", "Ecology and Evolutionary Biology", "Life Sciences", "Natural Resources and Environment", "Nature Conservation", "Northern Hardwood Forests", "04 agricultural and veterinary sciences", "15. Life on land", "Microbial Respiration", "Nitrification", "01 natural sciences", "Environmental Management", "N Mineralization", "Geoecology/Natural Processes", "13. Climate action", "Atmospheric NO 3 \u2212 Deposition", "0401 agriculture", " forestry", " and fisheries", "Zoology"]}, "links": [{"href": "https://doi.org/10.1007/s10021-005-0085-7"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Ecosystems", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s10021-005-0085-7", "name": "item", "description": "10.1007/s10021-005-0085-7", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10021-005-0085-7"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2006-03-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Geoecology%2FNatural+Processes&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Geoecology%2FNatural+Processes&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Geoecology%2FNatural+Processes&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=Geoecology%2FNatural+Processes&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-07-26T08:15:07.446371Z"}