• Journal of Ecology and Environment
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• 제46권1호
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• pp.8-17
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• 2022

Background: Parthenium hysterophorus L. (Asteraceae; hereafter Parthenium) is an invasive alien species of global significance because of its' negative ecological and socioeconomic impacts. This species is spreading rapidly from lowland Tarai to Middle Mountain regions in Nepal. In the present study, we analyzed the impacts of Parthenium on plant community composition including their soil seedbank in subtropical grasslands located in central Nepal. Data was collected in a 10 m long transects passing through areas of high (> 90% cover), medium (40%-60%) and low (< 10%) levels of Parthenium cover using a plot of 1 m². Altogether, we sampled 90 plots in 30 transects. Seedling emergence method was used to estimate soil seedbank density in the soil samples (0-10 cm depth) collected from the plots with high Parthenium cover. Results: There was no significant difference in the plant species richness at different levels of Parthenium invasion whereas there was a significant change in the species composition of above ground flora due to Parthenium invasion. There was also a significant difference in species composition between soil seedbank and aboveground flora in the highly invaded plots. Parthenium was the most dominant in soil seedbank, contributing 65% to the total soil seedbank. Conclusions: Our study suggests that Parthenium has considerable negative impact on the native grassland flora, and the dominance of Parthenium in the soil seedbank means there is a challenge for its management. It also suggests the need of monitoring the soil seedbank dynamics while managing Parthenium weed.

• Journal of Ecology and Environment
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• 제43권2호
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• pp.271-281
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• 2019

Background: The plant communities within reservoir drawdown zones are ecologically important as they provide a range of ecosystem services such as stabilizing the shoreline, improving water quality, enhancing biodiversity, and mitigating climate change. The aim of the study was therefore to identify the major environmental factors affecting these plant communities within the drawdown zone of the Soyangho Reservoir in South Korea, which experiences a monsoonal climate, and thereafter to (1) elucidate the plant species responses and (2) compare the soil seedbank composition along main environmental gradients. Results: Two main environmental gradients affecting the plant community structure were identified within the drawdown zone; these were a vertical and longitudinal gradient. On the vertical dimension, a hydrological gradient of flood/exposure, the annual-dominated plant community near the water edge changed to a perennial-dominated community at the highest elevation. On the longitudinal dimension from the dam to the upstream, plant species composition changed from an upland forest-edge community to a lowland riverine community, and this was correlated with slope degree, soil particle size, and soil moisture content. Simultaneously, the composition of the soil seedbank was separated along the vertical gradient of the drawdown zone, with mainly annuals near the water edge and some perennials at higher elevations. The species composition similarity between the seedbank and extant vegetation was greater in the annual communities at low elevation than in the perennial communities at higher elevation. Conclusions: The structures of plant community and soil seedbank in the drawdown zone of a monsoonal riverine reservoir were changed first along the vertical and secondly along the longitudinal gradients. The soil seedbank could play an important role on the vegetation regeneration after the disturbances of flood/exposure in the drawdown zone. These results indicate that it is important to understand the vertical and longitudinal environmental gradients affecting shoreline plant community structure and the role of soil seedbanks on the rapid vegetation regeneration for conserving and restoring the drawdown zone of a monsoonal reservoir.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제1권1호
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• pp.22-30
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• 2020

Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested.

• Weed & Turfgrass Science
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• 제1권4호
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• pp.1-5
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• 2012

번거로운 토양 종자은행 조사를 위해 간편한 모니터링 방법을 고안하였으며 이를 이용하여 경운과 무경운에 따른 토양내 잡초종자의 수직적 분포 양상을 관찰하였다. 본 시험은 강원도 화천의 유기농 옥수수 포장에서 수행되었다. 포장의 조성은 2010년부터 경운과 무경운 조건으로 2년간 조성된 무경운 포장에서 30 cm 깊이의 비파괴 토양 시료를 채취한 후 그 안에서 발생하는 잡초를 헤아려 종자의 토양 분포정도를 조사하였다. 토양속 잡초 종자의 분포는 경운구의 경우 15 cm 이내에 75%의 종자가 분포되어 있는 등 30 cm 깊이까지 대체로 고르게 분포되고 있었던 반면 무경운 조건에서는 15 cm 이내에 85% 이상의 종자가, 20 cm 이내에 93%의 종자가 분포되어 대체로 토양 표면에 집중되었다. 한편 잡초의 발생초종수와 개체수는 경운구가 무경운구에 비해 3배나 많은 양이 발생되었으며 주요 우점초종은 돌피, 석류풀, 바랭이 등의 일년생 초종이었다.

• 한국산림과학회지
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• 제110권4호
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• pp.577-589
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• 2021

매토종자는 식물의 장기 보존과 식생 동태에 기여하며, 토양 깊이에 따라 다양성과 밀도가 감소하는 특성으로 인해 군집의 다양성 감소과정 이해에 필요한 핵심관점(예측성 및 무작위성)을 제공한다. 우리는 한반도 온대중부 식생기후의 성숙림인 광릉숲에서 지표식생을 포함하여 토양층위(상토 및 하토) 별 종조성 및 다양성의 변화 및 구조화 양상을 분석하였다. 수직 10 cm 차이를 두고 채집된 두 층의 토양에서 27과 40속 44종 3변종 47분류군의 총 934개체가 발아하였다. 광릉숲의 매토종자는 초본의 구성 비율보다 목본 식물의 다양성 및 발아 밀도가 높았고, 빈터종보다는 가장자리종이 풍부하였다. 생육형을 비롯한 대부분의 비교 특성에서 종 풍부도와 발아밀도는 감소하였지만 큰 편차에 의해 통계적 유의성은 없었다. 상토 및 하토에서 종조성의 집단 내 변이성은 유사하였고, 공통 출현종(제타다양성)의 감소 및 종의 잔존 확률 변화 경향 역시 거의 유사하였다. 토양 내 두 군집 종조합의 구조화 과정은 멱함수보다는 지수 상관으로 적합되어 무작위 과정의 우세를 보였다. 광릉숲에서 토양 깊이(10cm) 별 군집 종조성 및 다양성의 양상은 형질 특성과 상호작용 보다는 종자의 수직 이동에 따른 이입 및 소실의 임의 과정(stochastic processes)에 의해 구조화되는 것으로 평가되었다.

• Ecology and Resilient Infrastructure
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• 제2권1호
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• pp.99-104
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• 2015

다수의 매토종자를 함유하고 있는 표토는 중요한 생태복원 재료로서 많이 알려져 있으나, 이를 실제로 활용하는 구체적인 방법에 대한 자료는 부족한 실정이다. 본 연구에서 하천복원 재료로서 표토의 가치에 대해 재평가하였다. 또한 실제로 황구지천 하천환경정비사업에서 완경사 호안, 고수부 복원, 식재 등에 표토를 활용한 결과 생태적, 치수적, 경제적 및 시공적 측면에서 자연친화적 하천 복원에 매우 효과적이었다. 결론적으로 표토가 하천복원의 유용한 재료인 것을 확인하였다.