• Journal of Ecology and Environment
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• v.38 no.2
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• pp.185-193
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• 2015

A dramatic decline in the abundance of the scaled quail (Callipepla squamata) has been observed across most of its geographic range. In order to evaluate the influence of land cover patterns and their changes on scaled quail abundance, we examined landscape patterns and their changes from the 1970s to the1990s in two large ecoregions with contrasting population trends: (1) the Rolling Plains ecoregion with a significantly decreased scaled quail population and (2) the South Texas Plains ecoregion with a relatively stable scaled quail population. The National Land Cover Database (NLCD) and the U.S. Geological Survey's (USGS) Land Use/Land Cover data were used to quantify landscape patterns and their changes based on 80 randomly located $20{\times}20km^2$ windows in each of the ecoregions. We found that landscapes in the Rolling Plains and the South Texas Plains were considerably different in composition and spatial characteristics related to scaled quail habitats. The landscapes in the South Texas Plains had significantly more shrubland and less grassland-herbaceous rangeland; and except for shrublands, they were more fragmented, with greater interspersion among land cover classes. Correlation analysis between the landscape metrics and the quail-abundance-survey data showed that shrublands appeared to be more important for scaled quail in the South Texas Plains, while grassland-herbaceous rangelands and pasture-croplands were essential to scaled quail habitats in the Rolling Plains. The decrease in the amount of grassland-herbaceous rangeland and spatial aggregation of pasture-croplands has likely contributed to the population decline of scaled quails in the Rolling Plains ecoregion.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.1
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• pp.25-34
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• 1979

To clealify the cause of barley and wheat sterility that occurred 77 / 78 cultivation period in Yeongnam area, a few environmental conditions were analyzed. The results are summarized as follows; 1. During the important growing stages such as meiosis and heading stages of barley encountered with severe droughtiness and unusual low temperature. 2. Soil moisture contents in the double cropping paddy soils were higher than cultivated uplands, and in the subsoils than the surface soils, in the clay soils than the sandy soils, in the northern aspect than the southern aspect of slope, respectively. 3. The sterilizing percentage of barley in the double cropping paddy fields were lower than cultivated uplands, in the alluvial fans and plains were lower than cultivated uplands, in the alluvial fans and plains were lower than in rolling or in foot slopes and the northerm aspect of slopes were lower than southern aspect. 4. The sterilizing percentage in the sandy soils were higher than clay soils and in the soils that have shallower plowing layer and shallower available depth had higher sterility. 5. The sterilizing percentage of barley had negative correlation with soil moisture contents in the surface and subsoils in both of cultivated upland or double cropping paddy fields. 6. The droughtiness that prevailed over reproductive growing stages of barley might be cause the sterility and the severe coldness also could be accelerate the phenomenon.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.338-343
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• 2019

This study was conducted to nominate optimal ground cover plants eventually enhancing Aronia production in the highland rolling plains. Total number of 17 weed species were observed in Aronia field when no cover plant was applied. Meanwhile, 12, 14, 15 and 16 weed species were observed when kentucky bluegrass, white clover, rattail fescue and ground ivy were used, respectively. Untreated native weed species were 73.6 cm tall before cut, and kentucky bluegrass, white clover, Rattail fescue and ground ivy were 57.5, 36.8, 48.3 and 40.9 cm, respectively. Based on plant height before cut, two shortest plants, white clover and ground ivy, were considered effective as ground cover plants in Aronia field. Coverage at $3^{rd}$ year by cover plants ranged from 85% to 100%. Coverage of uncovered Aronia field by native weed species was 95% while coverage by 4 treatments, kentucky bluegrass, white clover, rattail fescue and ground ivy were 100, 87, 85 and 100%, respectively. Aronia yield per plant at $3^{rd}$ year was 1,916 g with white clover cover followed by 1,770 g with Rattail fescue, 1,766 g with ground ivy, 1,098 g without cover plants and 931 g with Kentucky Bluegrass. Out results indicated that ground ivy was the best among all treatments based on 3 criteria, (1) short plant architecture, (2) rapid ground covering and (3) better weed control. In addition, ground ivy cover appeared to secure better yield.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.265-275
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• 1985

Present studies were carried out to investigate the distribution and formation of organic tiers contained paddy soils in Honam area characteristics to give basic informations on the effective utilization, management and improvement of the soils. The results obtained were summarized as follows; 1. The extent of organic tiers contained paddy soils in Honam area were 6.538㏊ and the amount of peat deposits were presumed about 2.41 million M/T. 2. Out of the total extent of the organic tiers contained paddy soils, about 97.6% was distributed in Honam plains (water-sheds of Mangyeong-Dongjin river), while about 1.5% in the Naju plains (water-sheds of Yeongsan river), and 0.9% in the Wando and Yeocheon areas. 3. The period of peat formation was presumed to be about the early of Seung Moon period (B.C. 4,250), and the Gongdeog series and the Bongnam series were formed in the bog conditions close to the valley mouth of near rolling and hill with small steram channels, and the Gimje series was formed in the out-skirts plains of the Gongdeog and Bongnam soils. 4. In the casue of peat formation, it was presumed to be the Gimje series that accumulated the fibrous peat out of the autochthonous peat such as reeds and grasses etc, to be the Gongdeog and Bongnam series that accumulated the autochtonous peat and the xylem and fibrous peat out of first allochthonous peat. 5. In the Organic horizons of these soils, the range of muck and peat horizons were in 62-68cm and 68-137cm of soil profile in the Gongdeog series, 52-84cm and 84-113cm in the Bongnam series respectively, one of muck horizon was in 46-71cm in the Gimje series. 6. The marks of soil horizons of the soils were expressed that the lower soils than the horizon of muck and peat were formed Cg, Aag for the muck horizon, 0 for the peat horizon, 0 of peat horizon were distingushed with Oag and Oig according to Organic forms. 7. The depthe occurred the muck and peat horizons were positively correlated with the width of local in the Gongdeog series ($r=0.881^{**}$, $r=0.827^{**}$), but not in the Bongnam series and Gimje series.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.265-270
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• 1989

Soil properties for the limestone-derived soil were examined to relate soil formation to stratigraphy of parent materials and hillslope positions in Bangjeol Ri, Yeongweol Eup, Gangweon Do. Pyeongchang, Anmi, Yulgog and Mungyeong series were described for topographic positions such as shoulder position, footslope, terrace and local bottom associated with toposequence where the landscape consisted of gently rolling hillslopes and nearly level plains. 1. Pyeongchang, Anmi, Yulgog and Mungyeong series had the standard hue of the 2.5YR, 5YR, 10YR and 2.5Y, respectively. Thus, color sequence of soil could be related to hillslope positions on the landscape. 2. With ascending slope toward summit, the clay content increased while silt content decreased 3. Silt/Clay ratios ranged from 0.27 to 3.76 and it was increased with descending to bottom. It, also, appeared that maturity of soil was higher at summit position than at bottom. 4. Soils developed in limestone were neutral in soil reaction and very low in available $P_2O_5$. OM, available $SiO_2$, CEC, and active Fe in soils seemed to be increased with ascending to summit position.