道路景观设计方法探讨

提出对道路景观的规划、调查、定位等系统分析,从而在道路的形态、周边环境的借景及路域生态系统的景观绿化等方面,探讨了道路景观设计的方法。     

日光温室内外金太阳杏光合特性的比较研究

为了探明杏对设施栽培的生理反应,对日光温室内外金太阳杏光合特性进行了比较研究。结果表明,日光温室栽培条件下,金太阳杏单位重量叶片的叶绿素含量增加;光(CO2)饱和点和光(CO2)补偿点降低鸦露地晴天净光合速率Pn日变化呈明显的双峰曲线,温室内也呈双峰线,但双峰出现原因不同。并且研究了影响光合作用的主要生态因子及变化规律,发现净光合速率与胞间CO2浓度、蒸腾作用、气温、叶温、光合有效辐射等因子相关。     

Growth response of Ficus benjamina to limited soil volume and soil dilution in a skeletal soil container study

The interactive effects of rooting volume and nutrient availability in a skeletal soil medium designed to meet street tree and pavement needs were observed in a containerized experiment. Benjamin fig (Ficus benjamina L.) was grown in a stone-soil blended skeletal soil material (CU-Soil™) and compared to a loam soil. The same topsoil used as the soil component in the skeletal soil material was used as the sole component in the comparison soil-only treatment.Plants grown in the skeletal soil material had reduced leaf tissue N content and depressed growth compared with plants grown in non-diluted soil. No other mineral deficiencies were found. Leaf number, chlorophyll concentration, shoot weight, and root characteristics were all affected.Reduced growth from soil dilution could be offset by the provision of an enlarged rooting volume for root development. Large containers of skeletal soil were observed to have smaller root systems compared to equivalent net volumes of loam soil at the first two harvest dates of the study. By the end of the study, the large containers of skeletal soil were observed to have developed larger root systems compared to equivalent net volumes of loam soil; resulting in comparable leaf N levels and total plant dry matter. Plants in skeletal soil had lower shoot: root ratios at the end of the study. Investing resources to further root growth in times of nutrient shortages is a probable plant reaction as evidenced by differences in specific root length between treatments. The study allowed a method for directly partitioning the containerization effect by having equivalent amounts of soil over two volumes.     

甜菜碱在果树胁迫中的作用

甜菜碱是一种非毒性渗透调节物质,对维持逆境胁迫下果树的代谢和生存具有重要的生理意义,系统讨论了甜菜碱在植物胁迫条件下的作用机制。由于并非所有植物在胁迫条件下会产生内源甜菜碱,因此外源甜菜碱使植物获得抗性的研究受到广泛关注。现对不同途径添加外源甜菜碱在果树抗逆过程中所起的作用进行举例说明,试图为增强果树的抗逆性提供新的技术措施。     

绿盲蝽越冬卵在苹果园中的空间分布型及抽样技术

近年来绿盲蝽Apolygus lucorum已经逐渐发展成为果树上的重要害虫之一, 对其越冬卵在果树上的空间分布型进行探究具有重要意义?本研究利用6种聚集度指标?Iwao回归方程和Taylor幂法则分析了苹果园中绿盲蝽越冬卵的空间分布型, 同时对苹果园绿盲蝽越冬卵聚集的原因和最适理论抽样数进行了分析与计算?结果显示, 绿盲蝽越冬卵在苹果园呈聚集分布, 并且随着越冬卵密度的增加, 分布越聚集?绿盲蝽越冬卵的种群聚集是由其生活习性与周围环境共同引起的?运用绿盲蝽越冬卵空间分布型参数, 建立Iwao理论抽样数模型, 从而明确不同密度下绿盲蝽越冬卵的最适理论抽样数, 为今后绿盲蝽越冬卵在苹果园内密度的准确调查和种群密度的预测提供了理论依据?     

苹果树体磷素动态规律与施肥管理

以"富士"苹果树为试材,对果树体生物量和各器官及其皮层、木质部的磷含量和累积动态进行了研究,以期探讨果树磷素吸收、转运和分配规律.结果表明,3月26日至9月21日,树体生物量呈直线增加,果实采收后,生长缓慢,7月30日后,根系快速生长,植株、地上部及根系中磷累积迅速增加;枝、干和根系皮层内磷含量与累积7月30日最低,休眠期最高,皮层磷含量枝＞干＞根系;而木质部磷含量与累积4月30日达最低,木质部磷含量根系＞枝＞干;一年内,果树吸磷总量为28.72 kg/hm2,果实和叶片共带走磷素7.94 kg/hm2,7月30日至9月21日,吸收磷素18.32 kg/hm2,占吸收总量的63.8%,9月21日至1月15日,吸收磷素10.40 kg/hm2,占36.2%;苹果树(苹果产量48 t/hm2)年推荐施纯磷47.86 kg/hm2,果实收获后秋季基施磷17.33 kg/hm2,果实膨大期前追施磷30.53 kg/hm2.     

Drying half of the root-zone from mid fruit growth to maturity in ‘Hass’ avocado (Persea americana Mill.) trees for one season reduced fruit production in two years

We tested the effect of extended drying of half the root system on fruit yield and fruit Ca concentration, an indirect measure of fruit quality, in avocado (Persea americana Mill. cv Hass). In a field experiment on a sandy soil, withholding irrigation and plastic sheeting was used to dry the root-zone beneath the whole canopy (DD) or half the canopy (WD), compared with well-watered trees (WW). The irrigation water contained added nutrients and was slightly saline. Yield, shoot growth, leaf conductance, leaf and fruit water status and mineral concentrations of leaves and fruit were studied. The responses of treated trees were assessed in the following season during which normal irrigation practices were restored. With respect to yield, the WD treatment behaved the same as the DD treatment. It reduced yield by more than half and proportionately more than the reduction in water supply thus reducing irrigation efficiency. Re-watering did not restore yield of WD or DD-trees in the next season. The WD and DD treatments had no effect on the concentration of Ca in the fruit mesocarp and so are unlikely to affect fruit quality. The main impact of reduced water supply on the trees was fruit abscission and this was linked to dry soil around the roots rather than the water status of the leaves or fruits. We conclude that extended drying of half of the root-zone in one season reduced irrigation efficiency for two seasons by promoting the abscission of developing fruit to the same extent as occurred when the whole root system was exposed to extended drying.     

果树嫁接的优势及关键技术

嫁接是果树无性繁殖的方法之一,即采取优良品种植株上的枝或芽接到另一植株的适当部位,使两者结合而生成新的植株。文章总结了嫁接在保持品种优良形状、丰产和提高抗逆性等方面的优势,介绍了常见的三种嫁接方法(T型芽接、木质芽接、插皮舌接);在此基础上提出了选择合适嫁接材料、注意嫁接时间、选择合适的嫁接方法、选取合适的生长点等提高嫁接成活率的措施。     

利用动态阈值决策树分类的华北平原冬小麦动态监测

华北平原是中国最大的粮食生产基地,准确监测其冬小麦种植面积及其变化对粮食产量预测和国家粮食安全具有重要意义。然而,不同土地利用产品所估算的小麦面积、空间分布及其动态均存在较大分歧,不能有效反映出冬小麦的长期变化特征。该研究结合作物物候特征和已有小麦专题数据产品,首先构建动态阈值决策分类算法,以降低传统方法在阈值设定和样本筛选方面的不确定性;进而分析了2003—2022年华北平原区冬小麦播种面积的长期变化规律。结果表明：1）该研究提出的动态阈值决策分类算法能准确地提取冬小麦面积,平均总体精度为93.44%,且与统计数据具有较高的一致性;2）2003—2022年华北平原冬小麦种植面积整体呈上升趋势,不同地区变化类型差异较大;3）研究时段内,持续种植冬小麦的耕地面积仅占各年份种植范围总面积的5%,种植次数低于10 a的面积占比达55%;4）河北中南部、山东省西部和河南省中北部冬小麦种植面积相对稳定,京津冀地区以及山区冬小麦播种面积变化相对频繁。该研究可为大尺度冬小麦动态监测提供了新的方法视角,并对科学制定耕地调控策略具有重要意义。     

受伤园林树木的保护与修复技术

介绍了园林绿化工程实践中常见倒伏受伤的园林树木的扶直、扶正、固定、树干疗伤、树洞修复、顶枝保护与修复、树干涂白等技术方法。