본 연구는 수변구역 매수토지의 복원에 영향을 미치는 요인을 파악하고 그 중요도를 정량적으로 산정하여 매수토지의 실질적 회복력을 분석하기 위한 평가지표 개발에 필요한 기초자료를 제시하고자 한다. 주요 결과는 다음과 같다. 첫째, 국내·외 관련연구에 대한 문헌고찰을 통해 34개의 회복탄력성 예비항목을 추출하였으며, 관련 전문가 델파이 조사를 통하여 생태적 대응력 7개, 물리적 대응력 6개, 관리적 대응력 4개 인자를 도출하였다. 둘째, 확정된 주요인자에 대한 신뢰도 분석, 계층적 의사결정법(AHP) 분석을 실시한 결과, 매수토지에 복원된 식생의 구조적 안정성, 야생동물 종다양도, 야생동물 구조적 안정성, 토지매수 후 복원시 습지의 규모, 출현 식물 종수, 매수토지와 인접한 주변 토지피복 현황이 중요인자로 도출되었다. 본 연구결과는 수변구역의 토지매수, 복원, 관리단계별 회복탄력성 강화인자를 고려한 생태적 복원과 관리계획에 유용한 정보로 활용될 수 있을 것으로 기대된다.
본 연구는 낙동강수계 매수토지 생태복원지를 대상으로 2007년 복원 공사 직후부터 4년간의 식생구조 변화를 모니터링하고 식생 관리방안을 제시하고자 하였다. 연구대상지는 낙동강 수계 생태복원지 중 총 15개소(208,342m2)를 대상지로 하였고 조사는 2007년 11월, 2008년 9월, 2009년 10월, 2010년 9월에 각각 시행하였다. 식재종 및 개체수 변화 분석 결과 교목층은 당단풍나무, 상수리나무, 신나무, 갈참나무, 굴참나무 등은 비교적 개체수가 증가하거나 변화가 없었고 떡갈나무, 말채나무, 뽕나무, 쪽동백나무, 팥배나무는 100% 고사한 것으로 나타났다. 관목은 초본과 덩굴성 식물에 의한 피압으로 대부분 고사하였다. 식재밀도는 4년간 평균 28주/100m2 → 20주/100m2 → 16주/100m2 → 16주/100m2로 감소하였다. 생장량은 복원 공사 직후 이식에 따른 스트레스로 다소 감소하였으나 이후 활착이 이루어짐에 따라 안정화되는 경향을 나타내었다. 흉고단면적 변화는 2007년 복원직후에 507.1cm2/100m2이던 것이 2008년에 301.8cm2/100m2로 감소하였으며 이후에는 324.9cm2/100m2(2009년), 372.7cm2/100m2(2010년)으로 다소 증가하는 경향을 나타내었다. 수변 생태복원지의 식재구조 개선을 위해서는 토양습도를 고려한 수종의 선정과 대상지 여건을 고려한 적정 식재구조의 차별화가 필요하였다.
The purpose of this study was to propose an efficient management plan for purchased land considering the hydrological, watershed characteristics and ecological functions of the target land and surrounding area based on the result of monitoring the water quality improvement effect obtained by purchasing the land in the watershed area in the Geum river system. For this purpose, this study investigated through literature review, and examined ways to apply them to this research by deriving implications from a comprehensive analysis of previous research cases. After that, the components of assessment were derived to evaluate the ecological function of the purchase land, and the ecological function evaluation model for each land and area was proposed. In order to select purchase and restoration priorities of the land, this study analyzed the ecological status of the purchased land in main watersheds and tributaries using Arc GIS ver 10.1. Through this, a process to select restoration priorities was developed. And this study constructed the integrated management process with proposing a mid - to long - term plan by integrating the purchased land valuation and restoration priority selection process. Based on this process, this study suggested an effective management plan for purchased land through the integrated ecological management system of lands purchased. It can be used systematically in appraisal valuation, land purchase system, restoration project, and follow-up management of land purchase.
Riparian management has become important as stream water quality as well as riparian ecosystem gain more public attentions. The objective of this study was to determine riparian widths based on the functions of nutrient removal and wildlife habitat protection and to apply for the Jinwee stream area as a preliminary case. Nitrogen and phosphorus filtration efficiencies were considered in water quality aspect, while the habitat radii of amphibian and reptiles were used for wildlife conservation purpose. In addition, observation of endangered species and human impact on wildlife disturbance in riparian area were also taken into account in determining riparian widths. The stream confluence zone was emphasized by doubling the riparian widths as the focal point for wildlife habitat conservation. As the results, three different levels of riparian widths were proposed depending on the major riparian functions and applied to the Jinwee stream section as the case study. The proposed method can be used to determine riparian width in other stream areas based on different functional focus, ie, water quality or riparian conservation purposes.
The growth conditions of planted trees, invasion of nuisance herbaceous species, competition between species, and effects of erosion control were monitored over five years in a riparian greenspace in Gapyeong County that was established through multilayered and grouped ecological planting. Of 156 trees planted in the upper and middle layers, 5.8% died. This tree death was attributed to poor drainage or aeration in the rooting zone from the clay-added root ball and too deep planting as well as a small-sized root ball and scanty fine roots. Of all the trees, 21.6% grew poorly due to transplant stress in the first year after planting, but they started to grow vigorously in the third year. This good growth was largely associated with soil improvement before planting, selection of appropriate tree species based on growth ground, and control of dryness and invasive climbing plants through surface mulching and multilayered/grouped planting. Mixed planting of fast-growing species as temporary trees was desirable for accelerating planting effect and increasing planting density. Thinning of fast-growing trees was required in the fifth year after planting to avoid considerable competition with target species. To reduce the invasion of herbaceous and climbing plants that oppress normal growth of planted trees, higher density planting of trees (crown opening of about 15%), woodchip mulching to a 10-cm depth, and edge planting 2 m wide were more effective than lower density planting (crown opening of 70%), no surface mulching, and no edge planting, respectively. This reduction effect was especially great during the first three years after planting. Nuisance herbaceous plants rarely invaded higher density planting with woodchip mulching over the five years. Higher density planting or woodchip mulching also showed much greater erosion control through rainfall interception and buffering than lower density planting with no mulching did. Based on these results, desirable planting and management strategies are suggested to improve the functions of riparian greenspaces.