Deciduous tree fruits such as pears and apples are widely grown in the Pacific Northwest of the United States and are well adapted to the seasonal environment in that region. Extended cold periods provide adequate chilling to break dormancy and reinitiate growth in the spring. Cold exposure synchronizes the physiological processes and makes sure that bloom is uniform and that fruit matures in a uniform manner. As a result of global warming, some fruit-growing areas may experience inadequate cold exposure during the winter months, gradually shifting the southern boundary for production of deciduous fruits further north. However, climate change will affect not only growth and fruiting habits of fruit trees but also the insect and mite pests which feed on them. There is general agreement that in temperate regions a trend towards warmer summers and milder winters will generally benefit insect and mite pests and increase their injuriousness. Temperature changes in particular will impact the development, mortality, phenology, and voltinism of fruit pests. Here we discuss how climate change may affect pests and control practices on deciduous tree fruits in the Hood River Valley of northern Oregon. This small valley extends in a north-south direction from the Columbia River to the foothills of Mt. Hood and is characterized by a varied topography and large altitudinal differences (sea level to 600 m). The major pest of pears and apples in that area is codling moth, Cydia pomonella L., a cosmopolitan pest which is present in most deciduous fruit-growing areas of the world. Like its host trees, the codling moth is well adapted to a seasonal environment. Diapause is the principal mechanism which synchronizes its phenology with the tree and the presence of fruit, the larval food source. Diapausing overwintering larvae require cold exposure (chilling) to terminate diapause in late winter or early spring. At the lower elevations close to the Columbia River the codling moth is bivoltine but gradually becomes univoltine at the higher elevations where the growing season is shorter and fewer heat units (above 10oC) are available for development. Long-term temperature records from the lower Hood River Valley indicate that the 25 years since 1985 have been considerable warmer than the 25 years prior to 1985. For instance, the average heat units available for codling moth development over a season have increased by more than 10% over the last 25 years. The codling moth is adapting to this warming trend by gradually increasing its voltinism (number of generations). As a result, the severity of codling moth as a pest can be expected to increase. Therefore, fruit growers will have to adjust and intensify control practices to keep fruit free from codling moth damage. We will also explore how other fruit and foliage feeding pests which are part of the pest complex of pears and apples in northern Oregon fare under different global warming scenarios compared to codling moth.

빈도측정을 고려 한 삼림군립구조 조사시 교목층의 적정 조사구수를 결정하기 위하여 우점종인 물푸레나무의 중요치가 28.1%인 소백산지역 활엽수혼효림군집의 교목층을 대상으로 20개의 l0m × l0m 조사구를 설치한 후 종수-면적 곡선, performance curve, 통계학적 방법 등을 적용하였다. 종수-면적 곡선에 있어서 누적조사구수의 증가율보다 출현종수의 증가율이 낮은 최소 조사구수는 8개이었으며, 누적조사구수의 증가율에 비하여 출현종수의 증가율이 1/2 이하인 최소 조사구수는 11개이었다. 주요수종의 중요치에 의한 performance curve를 작성한 결과 우점종과 준우점종의 구분이 뚜렷해지는 최소 조사구수는 5개이었으며, 준우점종간의 구분도 뚜렷해지는 최소조사구수는 10개이었다. 따라서, 삼림군집 구조의 기본적인 측도인 출현종수와 중요치를 고려할 때 본 조사지에 있어서 l0m × l0m 교목층 조사구의 적정 조사구수는 10개인 것으로 나타났다. 이때, 군집을 대표한다고 할 수 있는 20개 전체조사구와의 유사도지수는 90% 이상이었으며, 모집단인 군집 종다양도에 대한 신뢰구간은 ±0.073이었다.

The standard emission rate(ERs) of isoprene was quantitatively measured in situ from Quercus mongolica Fischer that dominates more than about 85% of domestic oak trees. The ERs values in spring and summer were similar to 64.4 and 58.1 (㎍C/gdw/hr), respectively. The ERs in autumn, 7.06(㎍C/gdw/hr), was about 8～9 times lower than those in spring and summer. The coefficient of determination (r2) between ERs and CL․CT ranged from 0.593 to 0.836. The correlation coefficients between the ERs and PAR, the ER and temperature suggested that ERs have strong correlation with PAR(photosynthetically active radiation) and temperature. In addition, the high values of PAR, temperature, and ERs were found in the time zone of 15:00 ～17:00(spring), 15:00 ～ 16:00(summer), and 14:00 ～ 15:00(autumn).