叶幕微气候与葡萄生理、产量和品质形成之间基本关系的研究

本实验在北京地区生态条件下，建立了叶幕微气候和葡萄生长发育及生理（营养生长、有机物质代谢、产量和品质诸构成因素的器官生理）之间的基本关系，明确了叶幕微气候对葡萄整体生理的深刻影响；论证了叶幕微气候（尤其是叶幕光能总截留）对果实品质形成的决定作用，为北京地区及其类似气候条件下的葡萄栽培方式改良提供了叶幕微气候调控方面的理论依据。     

中幕微气候与葡萄生理,产量和品质形成之间基本关系的研究

本实验在北京地区生态条件下，建立了叶幕微气候和葡萄生长发育及生理（营养生长、有机物质代谢、产量和品质诸构成因素的器官生理）之间的基本关系，明确了叶幕微气候对葡萄整体生理的深刻影响；论证了叶幕微气候（尤其是叶幕光能总截留）对果实品质形成的决定作用，为北京地区及其类似气候条件下的葡萄栽培方式改良提供了叶幕微气候调控方面的理论依据。     

叶幕高度对“赤霞珠”葡萄叶幕微气候及其品质的影响

以"赤霞珠"葡萄为试材,采用单因素三水平设计方法,研究了葡萄的叶幕高度对叶幕微气候的影响,并分析了微气候的改变对葡萄酒品质的影响,为贺兰山东麓产区葡萄的优质生产栽培提供参考依据。结果表明:不同处理的叶幕内层光照依次为1.2m1.5m1.8m(指叶幕高度,下同);葡萄成熟期间不同处理的月平均气温日较差依次为1.2m1.5m1.8m;不同叶幕高度处理对葡萄的总糖含量、pH影响不显著,总酸含量随叶幕高度的增加而降低;不同处理葡萄酒单宁含量依次为1.5m1.2m1.8m,且1.5m处理比1.2、1.8 m处理高出200、230 mg·L-1,不同处理葡萄酒总酚含量依次为1.2m1.5m1.8m,花色苷含量依次为1.5m1.2m1.8m。综合考虑叶幕微气候、葡萄、葡萄酒品质指标,1.5m处理能提高"赤霞珠"葡萄及葡萄酒的品质,适宜在宁夏产区推广。     

光伏板对吐鲁番‘无核白’葡萄叶幕微气候、叶片质量及果实品质的影响

以吐鲁番7年生‘无核白’为试验材料,研究不同密度光伏板对‘无核白’叶幕微气候、叶片质量以及果实品质的影响,旨在找到合适的光伏板密度,为葡光互补新型栽培模式的推广提供科学依据。结果表明:随着光伏板密度的增大,叶幕空气温度降低,空气相对湿度增大,光照强度显著降低。‘无核白’葡萄叶片质量、果实品质随着光伏板密度的增大呈现出先上升后下降的变化趋势,中度遮阴条件下,‘无核白’叶片的纵、横径,叶绿素含量和果实中可溶性固形物含量均表现最佳。在吐鲁番地区采用光伏板遮阴对‘无核白’葡萄叶幕微气候有显著影响,适度遮阴有利于缓解夏季高温强光对葡萄生长发育的危害,但过度遮阴会产生负面影响。在吐鲁番地区推广葡光互补栽培模式时,建议选择光伏板的间隔为1.0 m。     

葡萄不同栽培方式叶幕光能利用的综合评估参数—叶幕受光指数

本文提出并论证了葡萄不同栽培方式叶幕光能利用的综合评估参数—叶幕受光指数（ＣＥ），并建立了ＣＥ值的测算系统。计算了国内外九种主要栽培方式的ＣＥ数值，并据此对这些栽培方式的叶幕结构的光能利用效率进行了排序简评。文中提出：ＣＥ≥１．４５为葡萄叶幕光能利用的最佳取值范围，并指出在不同条件下ＣＥ的取值范围有所变化。     

根际土壤湿度和叶幕微气候对葡萄叶片水分代谢影响的模拟分析

在盆栽条件下取得初级数据以后进行数学模拟和分析。结果表明：根际土壤湿度对葡萄叶片水分代谢过程影响显著。根际土壤湿度与叶片水势（ψ_(ＷＬ)）、气孔扩散阻力（Ｒ_s）、蒸腾速率（Ｔ_ｒ）的关系可用相应的Ｌｏｇｉｓｔｉｃ方程表示。方程的拐点被定义为根际土壤湿度阀值。根际土壤湿度对叶片水分代谢的进程也有影响。供水充足的植株，叶片蒸腾速率（Ｔ_ｒ）在一日内都维持较高水平，呈单峰曲线型。而水分亏缺植株，则表现出明显的“午休”现象，且一日内蒸腾作用很弱。叶幕微气候诸因子对葡萄叶片水分代谢的影响作用较为复杂，基本遵循多元线性相关关系。建立了Ｒ_ｓ、Ｔ_ｒ与叶幕微气候诸因子的关系模型。进一步分析了葡萄根际土壤湿度阀值漂移与叶幕微气候因子的关系，结果表明：随光照增强、温度升高、湿度下降，阀值增大。     

叶幕厚度对“赤霞珠”葡萄叶幕微气候、光合特性及果实品质的影响

机械修剪以其高效高质的优势逐渐受到国内外葡萄种植业青睐。为探究机械修剪对葡萄叶幕微气候、光合特性及果实品质的影响,以4年生"赤霞珠"品种为试材,叶幕厚度分别设置为70cm(不抹副梢)、85cm(抹副梢)、85cm(不抹副梢)、100cm(不抹副梢),并于生长期调查了葡萄叶面积,测定光照强度、光合指标及浆果品质,采用单因素方差分析(ANOVA)进行数据分析。结果表明:叶幕厚度对叶幕微气候无显著影响,但随叶幕增厚,果际周围温度略降、湿度略升、光照强度减弱;葡萄转色期,70cm(不抹副梢)叶幕光合速率较85cm(抹副梢)显著提高12.9%,85cm与100cm处理差异不大;70cm(不抹副梢)、85cm(抹副梢)处理能在提高产量的同时促使葡萄提前成熟,增加果实含糖量、pH及总花色素含量,100cm处理能提高总酚、单宁及总酸含量。总体来讲,山西晋中地区的"赤霞珠"葡萄叶幕厚度应选择70cm。     

避雨栽培对“户太八号”葡萄生长及果实发育的影响

以"户太八号"葡萄为试材,比较了露地栽培与避雨栽培2种模式下葡萄的生长发育状况、外观品质及理化性质。结果表明:避雨栽培极显著削弱了叶幕层光照强度,为常规栽培的68.71%;避雨栽培下葡萄日平均净光合速率降低12.10%,叶绿素含量平均降低5.57%;在叶幕微气候方面,避雨栽培下叶幕层日平均温度提高了1.68℃,日平均湿度降低了10.98%。与常规栽培比较,避雨栽培平均果粒质量降低了1.52g,平均果穗质量降低了92g;避雨栽培下葡萄的可溶性固形物高于常规栽培,差异不显著;含酸量在果实发育时期极显著低于常规栽培下的葡萄,且差值较大。避雨栽培可显著提高果实固酸比,提高果实品质。     

温室葡萄光照分布与果实品质研究

为选择理想的温室葡萄叶幕型,对温室内2种叶幕结构的光照分布和果实品质进行了测定分析。结果表明:叶幕I("V"形整枝"W"型叶幕)光照分布比较均匀,全天中各部位受光都较好,光照时间长,果实品质好,成熟期早;叶幕Ⅱ(单篱架垂直叶幕)光照分布不均匀,下层光照差,果实品质稍差。因此,温室葡萄栽培适宜采用"V"形整枝"W"型叶幕。     

冰酒葡萄威代尔单蔓龙干直立叶幕栽培技术

通过对冰酒葡萄连体自然冷冻栽培技术的摸索改进,研究总结了酿酒葡萄品种威代尔的单蔓龙干直立叶幕栽培技术,主要包括栽培地块与苗木选择、单蔓龙干直立叶幕树形整形修剪、肥水管理、花果管理、下架防寒、果实采收等方面。     

Rainfall interception and stem flow by eucalypt street trees – The impacts of canopy density and bark type

Understanding how trees influence water movement in an urban landscape is important because in an ‘engineered xeriscape’ small changes in rainfall frequency or magnitude have significant implications to plant water availability and mortality at one extreme, and stormwater runoff and flooding at the other. This study relates direct measures of tree canopy interception and discusses their implication for catchment hydrology in different urban landscape contexts. We measured canopy throughfall and stemflow under two eucalypt tree species in an urban street setting over a continuous five month period. Eucalyptus nicholii has a dense canopy and rough bark, whereas Eucalyptus saligna has a less-dense canopy and smooth bark. E. nicholii, with the greater plant area index, intercepted more of the smaller rainfall events, such that 44% of annual rainfall was intercepted as compared to 29% for the less dense E. saligna canopy (2010). Stemflow was less in amount and frequency for the rough barked E. nicholii as compared to the smooth barked E. saligna. However, annual estimates of stemflow to the ground surface for even the smooth barked E. saligna would only offset approximately 10 mm of the 200 mm intercepted by its canopy (2010).Tree canopy and bark characteristics should be considered when planting in pervious green space, or impervious streetscapes, because of their profound impact upon tree and surrounding water availability, soil water recharge or runoff. This study provides an evidence base for tree canopy impacts upon urban catchment hydrology, and suggests that rainfall and runoff reductions of up to 20% are quite possible in impervious streetscapes. Street tree canopies can function as a cost-effective compliment to water sensitive urban design for stormwater reduction benefits.     

20 years later: Does reduced soil area change overall tree growth?

Urban conditions have been thought to affect tree growth, but there is little conclusive evidence as to the severity of those influences or how various species respond differentially to urban stress. Reduced growth expectations are important to understand, because they affect design choices for the urban tree canopy, particularly as required by legislative mandate. Five tree species (Acer rubrum, Prunus serrulata, Pyrus calleryana, Quercus pallustris and Zelkova serrata) grown in parking lots ranging from 18 to 23 years old in central and northern New Jersey, USA were studied. Tree height, diameter at breast height (DBH), and canopy radius were measured, as was apparent plant available soil (nonpaved planting zone area). Tree DBH, commonly recorded for many municipal inventories, was found to be a useful predictor of canopy area. Data were normalized within site, to facilitate multiple site analysis. Across different parking lots, reductions in tree size were consistently associated with reduced apparent soil access. A previous study from Florida, USA was used for comparison of regional data, permitting conclusions on canopy reductions, relative to specification of design space for tree establishment.     

大蒜群体光合特性及其与产量关系的研究

 对大蒜群体光合特性及其与产量的关系进行了研究。结果表明, 大蒜群体光合速率(CPn) 随生育期先增后降, 蒜薹伸长期最高。CPn 日变化呈明显单峰曲线, 峰值在中午12 时左右。大蒜群体光合作用饱和光强为1 760μmol·m^{- 2}·s ^{- 1} ; 补偿点290μmol·m^{- 2}·s ^{- 1} ; CO₂ 饱和点和补偿点分别为1 883μmol·mol ^{- 1}和121μmol·mol ^{- 1} 。在种植密度为22. 5～52. 5 株/ m² , 叶面积指数(LAI) 为1. 39～3. 14 范围内, CPn 随种植密度和LAI 的增加而增加。低密度下产量随种植密度的增加而逐渐增加, 超过52. 5 株/ m² 时则减少, CPn 与大蒜产量成正相关。     

苹果树形改造对树冠结构和冠层光合能力的影响

为解决乔化密植苹果园树冠郁闭、光照差、产量低、品质差的问题, 于2001～2004年在北京昌平区十三陵农场(东经116°13′, 北纬40°13′, 海拔79 m) 对1986年定植的富士苹果(M alus domestica Borkh.‘Fuji’) 进行树形改造试验, 将三主枝疏散分层形逐步改造为高干开心形。经过3年的改造, 主干高度从0.29 m提高到1.37 m, 主枝数从15.8个减少到4.58个, 冬剪后枝数从2 119.73 ×10³ ·hm^{- 2}减少到814.07 ×10³ ·hm^{- 2} , 叶面积指数从3.98减少到2.31。改造后树冠的叶片和光照分布更加均匀, 低于30%的无效光区从43%减少到24%。通过对冠层光合作用的数值模拟发现, 改造树冠层的光合作用比未改树略有降低, 在整个生长季(5～9月) 改造树的冠层光合能力比未改造树小14.6%, 但平均单叶光合速率却增加40.4%。改造后苹果产量从27.3 t·hm^{- 2}增加到54.5 t·hm^{- 2} , 可溶性固形物从12.83%增加到15.55%。     

棚架下垂叶幕与水平叶幕对香百川葡萄叶片光合特性的影响

[目的]比较棚架下垂叶幕和水平叶幕下葡萄叶片臭氧伤害状况以及对光合性能的影响.[方法]以5年生的葡萄品种香百川为试材,利用臭氧监测仪监测7-9月份栽培环境中臭氧浓度,采用CIRAS-3便携式光合作用测定仪和Handy PEA测定2种叶幕叶片的净光合速率和荧光特性.[结果]下垂叶幕缓解了臭氧伤害情况,其主梢叶片发生臭氧伤...     

Quantifying urban tree canopy interception in the southeastern United States

Urban stormwater is a major contributor to surface water degradation in the United States, prompting cities to invest in ways to naturally capture, store, and slowly release runoff through green infrastructure (GI). An often overlooked, yet integral, component of GI is urban tree canopy, which functions as GI through the process of rainfall interception (i.e., rainfall captured and stored within the canopy prior to returning to the atmosphere via evaporation). Nine trees from three native species commonly found in urban areas in the southeastern United States were studied in three parks in Knoxville, TN, USA to quantify interception. Throughfall (rainfall that passes through the canopy) and stemflow (rainfall that travels down the trunk) data were collected with continuous measurements by a network of automatic rain gauges positioned underneath each tree canopy. Data were collected from January 2018 to May 2019 which resulted in 98 storm events collected for each red maple (Acer rubrum) and willow oak (Quercus phellos), and 97 storm events collected for each white pine (Pinus strobus). Annually, red maples, white pines, and willow oaks intercepted 24.4%, 52.4%, and 33.2% of gross throughfall, respectively. Seasonally, white pines performed the most consistently with interception varying only from 49.2% to 57.0% between seasons compared to an interception range of 13.2–39.7% and 17.5–54.2% for red maples and willow oaks, respectively. Results demonstrated the effect of event duration, rainfall intensity, and seasonality on the interception potential of each species. Overall, these observations are a step toward allowing the storage capacity of urban trees to be properly credited as part of efforts to reduce stormwater runoff.     

The impact of greenfield residential development on mature trees

Mature trees provide a range of ecosystem services in urban landscapes, represent important wildlife habitat, and impact positively on human wellbeing. However, mature trees are perceived as a risk to people and infrastructure and occupy land suitable for development. Trees are slow to reach ecological maturity and thus difficult to replace when removed. In this study, we: (a) quantified native canopy cover retained during residential development using aerial imagery; (b) identified where native trees are/are not retained within residential developments with a focus on mature trees; and (c) evaluated the effectiveness of current legal mechanisms for protecting native trees during residential development. Native canopy cover was reduced by 49% during residential development. Mature trees had the highest probability of retention within residential developments if they occurred within intact remnant vegetation. A lower probability of retention for mature trees was observed in urban green space, and almost no mature trees were retained in other areas within residential developments, such as residential blocks and road verges. Mature trees had greater probability of retention where the jurisdiction offered some legislative protection. The loss of mature trees during residential development could be reduced with a greater focus on avoiding the removal of existing trees during the planning stage rather than offsetting the impacts elsewhere; and by designing green space within residential developments to ensure adequate separation between mature trees and people and infrastructure.     

生姜群体光台特性的研究

利用田间同化箱对生姜的群体光合特性进行了研究。结果表明，生姜群体光合速率（ＣＰｎ）有明显的季节变化和日变化，随着季节的进展ＣＰｎ呈二次曲线型。ＣＰｎ的日变化呈单峰曲线，峰值出现在中午１２时左右。ＣＰｎ的峰值与旺盛生长季节相吻合。在本试验范围内单位土地面积的ＣＰｎ随ＬＡＩ的增加而增加，若以叶面积计算ＣＰｎ则随叶面积指数（ＬＡＩ）的增加而降低。在田间试验条件下ＣＰｎ随光强和ＣＯ２浓度的增加而增加，在自然光下未测到生姜ＣＰｎ的光饱和点。     

苹果开心形树冠不同部位光合与蒸腾能力的研究

 以18年生开心形富士苹果(Malus pumila Mill. ‘Red Fuji’) 为试材, 定点测定了冠层不同部位晴天时的光照分布、气孔导度、光合速率和蒸腾速率。结果表明, 树冠外围的光照强度、单叶光合能力比较高, 内膛、中部和外围叶片最大光合速率分别为13.46、14.69和15.98μmol·m^{- 2} ·s^{- 1}。气孔导度、光合速率和水分利用效率的日变化呈双峰曲线, 而蒸腾速率呈单峰曲线, 在中午外围叶片的蒸腾速率略有降低。内膛、中部和外围叶片在晴天的平均光合速率分别为4.53、6.63和6.54μmol·m^{- 2} ·s^{- 1} , 平均蒸腾速率分别为3.36、4.06和4.40μmol·m^{- 2} ·s^{- 1}。这说明苹果在冠层不同部位的光合与蒸腾能力存在一定的差别, 冠层中部的光合速率和水分利用效率最大, 外围的蒸腾能力最强, 内膛最差。