化学除草剂在林业防火上的应用

杂草对林业危害非常严重,它与果树、苗木、花卉、树木等栽培植物在生长期内对阳光、土壤中的水分和养分争夺十分激烈,有的传播病虫害,严重影响种植物的生长,特别是寄生攀附类恶性杂草能够直接危害种植物的生命，造成种植物的减产或绝收。更为严重的是林木内树下茂密的杂草在秋冬季干枯后是冬季森林火灾的直接隐患。所以，生长季节除草工作既能保障栽培植物的正常生长又能直接预防冬季火灾的发生，意义非常明显。     

桐果农间作园对小气候影响的研究

结果表明，桐果农间作园的建立，提高了生长初期的日平均气温和土壤温度，降低了夏季生长盛期的日平均气温。减小了植物生长季的地表日温差，增加了干燥季节的空气相对湿度。有利于减少危害，促进植物生长。     

灰霉病防治

正"灰霉病,大棚花卉的主要病害之一,主要危害花卉的花、果及叶片,在花卉的生长季节常伴随发生,尤其在冬春棚室生长期间。"灰霉病,大棚花卉的主要病害之一,主要危害花卉的花、果及叶片,在花卉的生长季节常伴随发生,尤其在冬春棚室生长期间。如果放松管理,该病就极易发生和流行,严重时可引起大量落花落叶,影响植物开花,降低观赏价值。     

秋季栽植常青树好处多

自古以来人们把植树季节定为春季和冬季，也就是在植物休眠期进行起苗移栽，年年如此，代代如此，成为传统的习惯。植物生长期不能起苗栽植的原因，是这段时间里的气温比较高，植物的蒸腾作用大，需要水份特别多，如果此时起苗截断根系，植物的叶子就会缺水枯黄落叶，最后...     

杉木球果主要害虫发生期与杉木球果生长期的关系

研究了杉木球果主要害虫发生期与杉木球果生长期（下同）的关系：杉木球果麦蛾在杉木球果的各个生长期都起危害作用，但在杉木球果直径达２．５ｃｍ左右时危害最严重；长角岗缘蝽在杉木球果直径达到２．５ｃｍ左右至种子达到生理成熟期间危害严重；杉木扁长蝽在杉木球果的各个生长期都起危害作用，在成熟的球果中能剥到大量的杉木扁长蝽若虫。     

毒死蜱、乙酰甲胺磷、阿维菌素防治枸杞瘿螨药效试验

枸杞生长期长，害虫种类多且危害严重。枸杞瘿螨是危害枸杞的主要螨类，危害广泛而严重。除4月中旬枸杞展叶，5月下旬，6月上旬新枝萌发瘿螨向嫩叶、新枝扩散而暴露于瘿外，其余时间都在瘿内危害，防治难度非常大。该试验在室内就40%毒死蜱、30%乙酰甲胺磷、0.9%阿维菌素3种药剂毒力及其对枸杞瘿螨防治效果进行试验检测，表明这3种药剂对枸杞瘿螨均有显著的防治效果，可以在生产中推广应用。     

绿色家园的彩叶植物

彩叶植物一般分为常色叶植物、春色叶植物和秋色叶植物三类。常色叶植物是指整个生长期内都呈现彩色叶色,而春色叶植物及秋色叶植物只是在生长期的某一段时间呈现彩色叶色。       

湘东黄脊竹蝗监测方法与防治效果研究

指出了湘东黄脊竹蝗主要危害毛竹，其次危害刚竹、水竹等，在食料缺乏时也危害水稻等禾本科农作物。通过建立监测调餐样地，针对湘东黄脊竹蝗各个生长期的不同特点，采取不同的防治措施，对防治效果进行了总结和探索。     

园林花卉：屋顶绿化技术

屋顶绿化是用植物材料来覆盖平台屋顶的一种绿地形式。由于屋顶绿化与大地隔离，因此屋顶种植的植物所需水分完全依靠自然降水和浇灌。受建筑荷重的限制，屋顶供种植的土层厚度较浅，有效土壤水的容量小，土壤易干燥，土壤温度变化幅度大。植物根部冬季易受冻害，夏季易受灼伤。加之屋顶风力比平地大、种植层的土壤易失水肥等因素，     

种子强吸水抗旱包衣技术

植物繁殖及更新最难度过的时期就是种子萌发和萌发后的幼苗生长期。在此期间，植物可持续供应水分，是植物成活的关键，水成为恢复植被的限制因子。强吸水抗旱(丸化)技术利用种子包衣剂中的高分子吸水树脂，解决了干旱、半干旱地区植物种子萌发和幼苗生长期水分需求问题，而且通过丸化技术解决了干旱、半干旱地区牧草种植、退耕还林(草)人工造林，种植时对水、肥、根瘤菌、农药、生长促进剂等的综合需要问题。     

宁夏枸杞春季霜冻指标研究

为给枸杞春季霜冻预报和预警提供参考,以3年生盆栽宁夏枸杞‘宁杞1号’为研究对象,于2016、2017、2018年在MSX-2F型霜冻箱内进行人工模拟霜冻试验,处理温度为-3、-4、-5、-6、-7、-8℃,处理时间为1、2、3h,研究不同温度和持续时间处理下宁夏枸杞花蕾期、初花期、盛花期的霜冻率,最终确定宁夏枸杞的霜冻等级。结果表明:根据霜冻率,将霜冻程度划分为3个等级,轻度为霜冻率低于40%,中度为霜冻率40%~80%,重度为霜冻率高于80%;不同低温和持续时间对宁夏枸杞花蕾期、初花期、盛花期的影响程度不同,温度越低、持续时间越长,宁夏枸杞的霜冻率越大;同一温度和持续时间处理下,花蕾期的耐霜冻性最强,初花期的次之,盛花期的最弱。     

Impacts of seasonal air and soil temperatures on photosynthesis in Scots pine trees

Seasonal courses of light-saturated rate of net photosynthesis (A360) and stomatal conductance (gs) were examined in detached 1-year-old needles of Scots pine (Pinus sylvestris L.) from early April to mid-November. To evaluate the effects of soil frost and low soil temperatures on gas exchange, the extent and duration of soil frost, as well as the onset of soil warming, were manipulated in the field. During spring, early summer and autumn, the patterns of A360 and gs in needles from the control and warm-soil plots were generally strongly related to daily mean air temperatures and the frequency of severe frost. The warm-soil treatment had little effect on gas exchange, although mean soil temperature in the warm-soil plot was 3.8 degrees C higher than in the control plot during spring and summer, indicating that A360 and gs in needles from control trees were not limited by low soil temperature alone. In contrast, prolonged exposure to soil temperatures slightly above 0 degrees C severely restricted recovery of A360 and especially gs in needles from the cold-soil treatment during spring and early summer; however, full recovery of both A360 and gs occurred in late summer. We conclude that inhibition of A360 by low soil temperatures is related to both stomatal closure and effects on the biochemistry of photosynthesis, the relative importance of which appeared to vary during spring and early summer. During the autumn, soil temperatures as low as 8 degrees C did not affect either A360 or gs.     

Climate warming and the risk of frost damage to boreal forest trees: identification of critical ecophysiological traits

According to a hypothesis presented in the mid-1980s, climate warming will, paradoxically, increase the risk of frost damage to trees in the boreal and temperate zones. Dehardening and even growth onset may occur in trees during mild spells in winter and early spring, resulting in damage during subsequent periods of frost. In the present study, ecophysiological traits critical to the occurrence of frost damage in trees in the boreal zone were identified. Diagnostic computer simulations were performed to examine why one simulation model of frost hardiness in an earlier study predicted heavy frost damage as a consequence of climate warming, whereas another closely related model did not. The modeling comparison revealed that the response of ontogenetic development to air temperature during quiescence is a critical factor determining the risk of frost damage. As the response can be readily determined in growth-chamber experiments, the findings of the present study can be used to guide experimental work on the environmental regulation of the annual cycle of frost hardiness in trees.     

Temperature control of the development of frost hardiness in two populations of Leptospermum scoparium

Seedlings of Leptospermum scoparium J.R. et G. Forst (manuka) originating from seed from a low altitude coastal site (Auckland) and from a high altitude inland site (Desert Road) were grown for 96 days in four controlled environments to compare the relationship between growth temperature and frost hardening. Day/night temperature treatments were 12/6, 12/3, 12/0 and 12/-3 degrees C. Frost hardiness was determined at 14-day intervals by exposing whole seedlings to temperatures ranging from -2 to -8 degrees C. Frost damage differed significantly between the two populations: Desert Road seedlings were less affected than Auckland seedlings. At all growth temperatures, the time courses of frost hardiness of both populations followed curvilinear relationships reaching a maximum hardiness at about Day 50, after which the seedlings spontaneously dehardened. The rate of frost hardening increased linearly with decreasing temperature from 6 to 0 degrees C, but thereafter, no further increase occurred with decreasing temperature to -3 degrees C. The frost hardening process was more sensitive to temperature in the Desert Road seedlings than in the Auckland seedlings, and this difference may account for the intraspecific variation in frost hardening capacity of this species. Comparisons with Pinus radiata D. Don and Lolium perenne L. indicated that interspecific variation in frost hardening capacity can also be accounted for by differences in the sensitivity of the hardening process to temperature.     

绿枝高接对猕猴桃成活及新梢生长量的影响

针对猕猴桃春季硬枝嫁接时期温度低、愈合时间长、枝条萌发后易受晚霜冻和溃疡病危害主杆、大枝而较难防治的情况,利用6～7月光照充足、雨量较多、温度适宜,在猕猴桃嫁接后接口愈合快、成活率高的特点,采用绿枝高位嫁接技术,可促进猕猴桃早萌芽、抽枝快、早成园。此技术的应用,为猕猴桃产业的发展、减轻枝杆病害探索出一条新途径。     

生理干旱对北方地区城市森林中针叶树生长的影响

常绿针叶树是北方地区城市森林的重要树种。在沈阳城市森林中,常绿针叶树约占公共绿地树木总量的20%。在严寒的冬季,北方城市中大部分树木落叶、休眠,惟有常绿针叶树保持着植物的生机,体现了城市的活力。然而,冬末和早春的生理干旱常常导致常绿针叶树松针失绿、枯黄甚至整株死亡,严重影响了城市绿化的景观效果。加强常绿针叶树生长季节和秋末的水、肥等管理,保持常绿针叶树旺盛的生长势,是减轻生理干旱影响的重要措施。       

洛南县蚕桑产业生产常见问题及对策

指出了洛南县栽桑养蚕历史悠久,近年来发展蚕桑产业成为该县农民脱贫致富的重要产业。由于蚕桑产业的发展受天气、当地政策、茧丝绸行情等诸多因素的影响,对洛南县蚕桑产业生产过程中出现的问题进行了梳理,探讨了霜冻、高温、多雨等对蚕桑产业有影响的常见问题,针对这些问题从冻前预防、冻后补救和科学养蚕3方面提出了相应的对策,以期提供参考。     

Broadleaf seedling responses to warmer temperatures “chilled” by late frost that favors conifers

Climate change includes not only shifts in mean conditions but also changes in the frequency and timing of extreme weather events. Tree seedlings, as the potential future overstory, are responding to the selective pressures of both mean and extreme conditions. We investigated how increases in mean temperature and the occurrence of late spring frosts affect emergence, development, growth, and survival of 13 native and non-native broadleaf and conifer tree species common in central Europe. Three temperature levels (ambient, +3, and +6 °C) and three spring frost treatments (control, late, and very late) were applied. Development responses of first-year seedlings to warmer temperatures were similar in direction and magnitude for broadleaf and conifer species. Stem size also increased with rising mean temperature for most species, though broadleaf species had maximal height advantage over conifer species in the warmest treatment. Sensitivity to frost differed sharply between the broadleaf and conifer groups. Broadleaf survival and stem length exhibited strong reductions due to frost events while conifer species only showed minor decreases in survival. Importantly, more rapid development and earlier leaf-out in response to warmer temperatures were associated with increased mortality from frost for broadleaf species but decreased mortality for conifer species. This research suggests that compositional shifts in the direction of species favored by increasing mean temperatures may be slowed by extreme events, and thus, the occurrence and impacts of such weather events must be acknowledged and incorporated into research and forest planning.     

民勤荒漠区无霜期及春季低温变化特征分析

以甘肃民勤治沙综合试验站数十年气象定点观测资料为基础,统计、分析了民勤荒漠区无霜期、春季低温、冻土层的变化特征。结果显示:该地区平均终霜期为5月10日,初霜期为9月28日,50 a来终霜期有逐渐提前、初霜期有逐渐推后的趋势,但不同年份变异幅度增大;3-5月份地表平均最低温度、气温逐渐上升,≤0℃出现比率下降,但4月下旬至5月上旬大强度的降温天气时有发生;3月份冻土层的变化与气温变化趋势相近。30 a以来地表平均日最低温度和气温亦有所提高。     

Fall frost resistance in willows used for biomass production. I. Characterization of seasonal and genetic variation

Fast-growing willow clones (six clones of Salix viminalis L. and one clone each of S. viminalis x S. schwerenii E. Wolf and S. dasyclados Wimm.) were compared with respect to growth rhythm and frost hardening in the fall. Frost resistance of stem tissues was assessed by controlled freezing followed by analysis of chlorophyll fluorescence and scoring of visible cambial discoloration. The fluorescence method proved superior to scoring based on visible cambial discoloration because it was more rapid and less subjective, but needed calibration against cambial damage. Frost hardening in mature parts of stems did not start until growth cessation was initiated in the shoot apices, irrespective of whether growth cessation occurred early or late in the fall. Frost resistance varied because of clonal variations in: (1) pre-hardening frost resistance; (2) timing of growth cessation and hence start of frost hardening; and (3) rate of frost hardening. Compared with coastal and southern clones, continental and northern clones started hardening earlier, and a continental clone proceeded through hardening more rapidly at a given temperature. A cross between a continental and coastal clone was intermediate in timing. The pre-hardening frost resistance, however, was unrelated to both growth and frost hardening characteristics.