• Title/Summary/Keyword: Remnant natural populations

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Experimental Techniques for Evaluating the Success of Restoration Projects

  • Robinson, George R.;Handel, Steven-N.l;Mattei, Jennifer
    • The Korean Journal of Ecology
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    • v.25 no.1
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    • pp.1-7
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    • 2002
  • The ecological background of a restoration project is complex and difficult to betermine without experimentation. A useful context for experiments is the well-studied process of natural succession, because the factors that drive or inhibit succession are also at work during reclamation (a form of primary succession) and restoration (which often resembles secondary succession). Using experimental studies on urban wasteland reclamation, we have tested for factors that stimulate or inhibit succession during early phases of woodland development in the Northeastern United states. The emphasis has been on mutualisms (seed dispersal, pollination, and mycorrhizae) and microsite limitations in the recruitment, growth, and reproduction of woody plants. Using plantings of seeds, seedlings, and clusters of reproductively mature plants on abandoned landfills, we have observed that (1) soil microsite deficiencies lead to very poor germination (<0.1$\%$) and seedling survival (<0.01$\%$) of most native species; (2) seed dispersal by birds is a significant and reliable source of woody plant recruitment; however (3) proximity effects are strong, with most (up to 95$\%$) of seed rain falling in the vicinity of planted clusters that are closest to putative seed sources; and (4) remnant natural woodlands are critical components of the recruitment process. To emphasize the last point, in one case, we found that the destruction of approximately 50$\%$ of nearby natural woodland vegetation led to a commensurate decline in seed rain. In another case, we found that the species richness of recruits was strictly limited by the species composition of nearby source plant communities, with no evidence of community enrichment by long distance dispersal over 5 years. We conclude from these results that the size and proximity of remnant natural populations are critical considerations when planning reclamation and restoration programs that rely on natural successional processes.

Actual distribution and present status of a threatened aquatic plant, Sagittaria aginashi (Alismataceae), in Korea

  • Shiga, Takashi;Tsubota, Kazumasa;Choi, Hyeok Jae
    • Korean Journal of Plant Taxonomy
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    • v.47 no.3
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    • pp.180-188
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    • 2017
  • We evaluated the actual distribution, present status, and number of remnant individuals of Korean Sagittaria aginashi (Alismataceae) based on herbarium specimens and field surveys. We also reidentified Korean S. aginashi by analyzing sequences of the internal transcribed spacer (ITS) region. We found nine specimens of S. aginashi in herbaria from four localities housed at the Osaka Museum of Natural History (OSA) and at the Korea National Herbarium (KH). During our field research, we could not confirm the current statuses of two collection localities (Taereung and Ansan-si), though this was not the case for Ulsan-si. In addition, we found two new localities in Ulsan-si and Yangsan-si. These three remnant populations are distributed in wetlands in mountainous areas (elev. 480-740 m). With regard to the number of flowering and immature individuals in the three localities, there were <50 and <2,000, respectively, in total. ITS sequences demonstrated that the sequences of Korean and Japanese S. aginashi are uniform and distinct from other Sagittaria species. These results indicate that S. aginashi is a rare and threatened species in Korea. It should be listed as an endangered species on the Korean Red List and requires urgent protection by conservation programs, including the extensive surveys of other possible natural habitats.

Characteristics of Habitats and Small Rodent Populations caused by Different Remnant Treatments on Forest Floor in Fired Coniferous Forest (산불피해지역에서 임상잔존물의 처리에 따른 서식환경과 소형 설치류 개체군 특성)

  • Lee, Eun Jae;Lee, Woo-Shin;Lee, Young-Geun;Lee, Myung-Bo;Rhim, Shin-Jae
    • Journal of Korean Society of Forest Science
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    • v.95 no.6
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    • pp.711-715
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    • 2006
  • This study was conducted to clarify the characteristics of habitats and small rodent populations between remnant removed and left areas caused by different remnant treatment on forest floor in fired coniferous forest, Mt Gumbong, Samcheok, Korea, There were higher value of variables of understory coverage, snags, downed coarse woody debris (CWD) in natural restored area. Mean number of captured individuals and body weights of Apodemus peninsulae and Eothenomys regulus were more higher in remnant left area than in removed area, The differences in density and body weight of small rodents would be related with habitats between both study areas. The remove of remnant trees on the forest floor would not be good for small rodents. The more detailed and long-term researches would be needed for proper restoration in fired forest area.