{"created":"2021-03-01T06:17:22.209596+00:00","id":820,"links":{},"metadata":{"_buckets":{"deposit":"4e05541d-c6fe-41db-9c80-09d670d4a827"},"_deposit":{"id":"820","owners":[],"pid":{"revision_id":0,"type":"depid","value":"820"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00000820","sets":["27:28:37","9:10:11"]},"item_2_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2008","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"154","bibliographicPageStart":"145","bibliographicVolumeNumber":"96","bibliographic_titles":[{"bibliographic_title":"The Journal of ecology"}]}]},"item_2_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"1.The concept of threshold has become important in ecology, but the nature of potential threshold responses of vegetation to grazing in rangeland ecosystems remains poorly understood. We aimed to identify ecological thresholds in vegetation changes along a grazing gradient and to examine whether threshold changes were expressed similarly at a variety of ecological sites. 2. To accomplish this, we surveyed the vegetation along grazing gradients at 10 ecological sites, each located at different landscape positions in Mongolia's central and southern rangelands. Evidence for a threshold in changes in floristic composition along the grazing gradient was examined by comparing linear models of the data with nonlinear models fitted using an exponential curve, an inverse curve, a piecewise regression and a sigmoid logistic curve. 3. Three nonlinear models (piecewise, exponential and sigmoid) provided a much better fit to the data than the linear models, highlighting the presence of a discontinuity in vegetation changes along the grazing gradient. The shapes of the best-fit models and their fit to the data were generally similar across sites, indicating that the changes in floristic composition were relatively constant below a threshold level of grazing, after which the curve changed sharply. 4. Except for two sites, the best-fit models had relatively narrow bootstrap confidence intervals (95% CI), especially around threshold points or zones where the rate of change accelerated, emphasizing that our results were robust and conclusive. 5. Synthesis. Our study provided strong evidence for the existence of ecological thresholds in vegetation change along a grazing gradient across all ecological sites. This suggests that vegetation responses to grazing in the study areas are essentially nonlinear. The recognition that real threshold changes exist in real grazing gradients will help land managers to prevent the occurrence of undesirable states and promote the occurrence of desirable states, and will therefore permit a major step forward in the sustainable management of rangeland ecosystems.","subitem_description_type":"Abstract"}]},"item_2_publisher_20":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"Wiley-Blackwell"}]},"item_2_relation_11":{"attribute_name":"DOI","attribute_value_mlt":[{"subitem_relation_type_id":{"subitem_relation_type_id_text":"info:doi/10.1111/j.1365-2745.2007.01315.x","subitem_relation_type_select":"DOI"}}]},"item_2_relation_26":{"attribute_name":"異版である","attribute_value_mlt":[{"subitem_relation_type":"isVersionOf","subitem_relation_type_id":{"subitem_relation_type_id_text":"http://doi.org/10.1111/j.1365-2745.2007.01315.x","subitem_relation_type_select":"URI"}}]},"item_2_select_14":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_select_item":"author"}]},"item_2_source_id_10":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AA00696840","subitem_source_identifier_type":"NCID"}]},"item_2_source_id_8":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"0022-0477","subitem_source_identifier_type":"ISSN"}]},"item_2_subject_15":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"290.13","subitem_subject_scheme":"NDC"},{"subitem_subject":"629","subitem_subject_scheme":"NDC"}]},"item_2_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"Department of Ecosystem Studies, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan"},{"subitem_text_value":"Center for Ecosystem Study, Mongolian State University of Agriculture, Mongolia"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Sasaki, Takehiro"}],"nameIdentifiers":[{"nameIdentifier":"3179","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"Okayasu, Tomoo"}],"nameIdentifiers":[{"nameIdentifier":"3180","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"Undarmaa, Jamsran"}],"nameIdentifiers":[{"nameIdentifier":"3181","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"Takeuchi, Kazuhiko"}],"nameIdentifiers":[{"nameIdentifier":"3182","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-05-30"}],"displaytype":"detail","filename":"J_Ecol_96_1_145.pdf","filesize":[{"value":"191.2 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"J_Ecol_96_1_145.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/820/files/J_Ecol_96_1_145.pdf"},"version_id":"6a4bc4d9-0d74-4b4b-b399-1cb2682fdbdd"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"arid and semi-arid rangelands","subitem_subject_scheme":"Other"},{"subitem_subject":"bootstrap confidence interval","subitem_subject_scheme":"Other"},{"subitem_subject":"ecological threshold","subitem_subject_scheme":"Other"},{"subitem_subject":"land degradation","subitem_subject_scheme":"Other"},{"subitem_subject":"Mongolia","subitem_subject_scheme":"Other"},{"subitem_subject":"ordination","subitem_subject_scheme":"Other"},{"subitem_subject":"piecewise regression model","subitem_subject_scheme":"Other"},{"subitem_subject":"plant functional types","subitem_subject_scheme":"Other"},{"subitem_subject":"rangeland management","subitem_subject_scheme":"Other"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"journal article","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"Threshold changes in vegetation along a grazing gradient in Mongolian rangelands","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Threshold changes in vegetation along a grazing gradient in Mongolian rangelands"}]},"item_type_id":"2","owner":"1","path":["11","37"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-01-06"},"publish_date":"2017-01-06","publish_status":"0","recid":"820","relation_version_is_last":true,"title":["Threshold changes in vegetation along a grazing gradient in Mongolian rangelands"],"weko_creator_id":"1","weko_shared_id":null},"updated":"2022-12-19T03:41:59.354374+00:00"}