Adolescents’ perceptions of park characteristics that discourage park visitation

Parks are key amenities of liveable cities that support physical activity and social interaction. However, parks are often not well attended by adolescents, and little is known about what park characteristics may discourage adolescents from visiting parks. The aim of this study was to explore what park characteristics adolescents perceive as most likely to discourage park visitation. Adolescents (n = 444, 13–18 years, 53% female) from seven schools in diverse areas of Melbourne, Australia completed an online survey at school. In response to an open-ended question, participants listed three park characteristics that would most likely discourage their park visitation. Content analysis was performed to determine categories of park characteristics from the coded responses. The six most frequently stated park characteristics that would discourage park visitation related to: play equipment (e.g., small/children’s playgrounds, no play equipment, no swings; 44% of participants mentioned the category at least once); social factors (e.g., crowded parks, presence of undesirable people; 32%); natural environment (e.g., small/no grassy space, large grassy open space; 28%); maintenance (e.g., dirty facilities, rubbish; 23%); sport/recreation features (e.g., skate park; 20%); and amenities (e.g., no shade, toilets, drink taps; 19%). To encourage more adolescents to increasingly visit parks, it is imperative for stakeholders to address the park features that they perceive as unappealing to ensure that park design caters to this important age group.     

Soundscape effects on visiting experience in city park: A case study in Fuzhou,China

The main objective of this study was to reveal the relationships between sound/soundscape perception and public visiting experience in city parks, based on a questionnaire survey of 146 park users in West Lake park in Fuzhou, China. The results indicated that, the three visiting experience indicators, i.e., soundscape tranquil degree (STD), landscape aesthetic degree (LAD) and visiting satisfaction degree (VSD) were positively related with each other, and LAD (correlation coefficients = 0.728, p < 0.01) was more associated with VSD than STD (correlation coefficients = 0.565, p < 0.01). Perception of certain individual sounds was found in close relationships with the three indicators. Specifically, STD showed the most significant relationships with harmonious degree of individual sounds, where perception of traffic sounds showed the most negative effects, while perception of music related sounds and water sound showed positive effects. LAD was more associated with perceived occurrences of individual sounds, where traffic sounds and music related sounds showed the most significant effects again. Both perceived occurrences and dominant degree of individual sounds showed the most and equal relationships with VSD. Specifically, mechanical sounds showed the most negative effects, and dog barking showed significant negative effects too, while music related sounds could be the only kind of sound positively contributed to VSD. Social/demographical/behavioral factors and visit motivations all showed significant relationships with individual sound perception and visiting experience. Considering the effects of all associated factors, key factors were detected for each of the visiting experience indicators. All the three visiting experience indicators showed negative relationships with certain traffic sounds, while tree rustling sound was the only sound showing positive relationship with STD. Age was the most important social/demographical/behavioral factor showing positive relationships with LAD and VSD. The research results provided theoretical references for management and design of soundscapes to contribute to more satisfied experiences in city parks.     

朝天椒苗期对水涝胁迫的生长及生理响应

以耐涝性不同的朝天椒品系‘ZHC1’‘ZHC2’和‘ZHS2’为试材,采用模拟短期水涝胁迫方法,研究了水涝胁迫对朝天椒苗期生长及生理指标的影响,以期探讨辣椒的耐涝机制。结果表明:在淹水24h(W24h),供试辣椒茎粗比对照显著增加;‘ZHC2’(耐涝)植株的鲜、干质量大于对照。在恢复24h(R24h)时,‘ZHC2’和‘ZHS2’(中等耐涝)株高分别比对照显著增加。水涝胁迫促进‘ZHC2’和‘ZHS2’根系浅层分布及不定根形成。‘ZHC2’叶绿素受水涝胁迫的伤害较小,淹水时类胡萝卜素含量升高。水涝胁迫下3个辣椒品系的可溶性糖、脯氨酸含量上升。每个时期‘ZHC2’叶片和根系中丙二醛(MDA)含量最低,‘ZHC1’则最高。总之,茎增粗,根系浅层分布及不定根形成,叶绿素受伤害较小,类胡萝卜素、可溶性糖及脯氨酸含量上升可能有助于提高‘ZHC2’的耐涝性及淹水后的生长恢复。不定根形成、类胡萝卜素及丙二醛含量是朝天椒耐涝性鉴定的重要指标。     

低温胁迫下番茄幼苗根穗互作对其抗坏血酸—谷胱甘肽循环的影响

为探讨番茄根系与接穗及其互作效应影响嫁接苗耐冷性的效应大小与生理机制,以耐冷性强的番茄‘060112’(R)和冷敏感番茄‘060911’(S)为试材,采用靠接法进行嫁接,组成双根双穗嫁接苗RS/RS,待嫁接苗成活后通过断根或断穗,形成R/R、R/RS、R/S、S/R、S/RS和S/S共6个根/穗组合处理,置于光强22 klx、光周期12 h/12 h光照培养箱,测定昼夜温度10℃/3℃低温胁迫9 d及25℃/15℃常温恢复3 d时嫁接苗叶片和根系中活性氧水平及As A-GSH循环中关键酶和抗氧化物质的变化。结果表明,低温胁迫显著提高了番茄嫁接苗叶片和根系中H_2O_2含量及超氧阴离子产生速率,但耐冷性强的R根系嫁接苗活性氧水平显著低于冷敏感的S根系嫁接苗,虽然R接穗嫁接苗活性氧水平亦显著低于S接穗嫁接苗,但降幅不及根系嫁接苗的大,表明根系在增强嫁接苗耐冷性中的作用大于接穗。低温胁迫下,各处理嫁接苗叶片和根系As A-GSH循环中关键酶(APX、MDHAR、DHAR、GR)活性和抗氧化物质(As A、DHA、GSH、GSSG)的含量均显著增加,且除DHA和GSSG外,均以R根系或R接穗嫁接苗较高,S根系或S接穗嫁接苗较低,RS根系或RS接穗嫁接苗居中,表明低温胁迫下耐冷性强的R根系或接穗嫁接苗的抗氧化能力显著高于S根系或接穗嫁接苗。具RS双接穗的嫁接苗中又以RS-R叶片的抗氧化能力显著高于RS-S叶片,且互作效应的P值小于0.01(或0.05),表明根、穗对嫁接苗耐冷性存在显著的互作效应。     

Landscape Position, Local Environmental Factors, and the Structure of Molluscan Assemblages of Lakes

Biotic communities are structured by both regional processes (e.g., dispersal) and local environmental conditions (e.g., stress). We examined the relative importance of landscape position (position within the hydrologic flow system and distance from other lakes) and local environmental factors in determining the assemblage structure of lake-dwelling snails and fingernail clams in a boreal landscape. Both landscape position and local environmental factors were highly influential in structuring the molluscan assemblages. In canonical correspondence analysis, 53.6% of snail and 48.2% of fingernail clam assemblage composition were accounted for by both sets of variables. The pure effects of landscape position were higher than those of environmental variables, and a considerable amount of variability was shared by the two sets of variables. In regression analysis, 95.5% of snail and 62.2% of fingernail clam species richness was accounted for by the explanatory variable groups, with most of the variability being related to shared effects, followed by landscape position. The effects of landscape position on species composition suggest that passive dispersal increases the similarity of molluscan assemblages in adjacent lakes. This process does not lead to an overall homogenisation of assemblage composition across the landscape, however, because local conditions set a strong environmental filter, excluding species that arrive at an unsuitable lake. These environmental filters may reflect either extinction probability (area, productivity) or species niche differences (calcium levels, abiotic stress). Landscape position may also be important in maintaining the species richness of lake-dwelling molluscan assemblages. By providing potential colonists, nearby source lakes are likely to be important in countering local extinctions. Our test of the relative importance of landscape position and local drivers of assemblage structure was partly confounded by their co-variation. Nevertheless, studying the relationship between landscape position and local variables is useful because it can tell us about the importance of local and regional processes in shaping lake communities.     

外源油菜素内酯对弱光下番茄幼苗光合碳同化关键酶及其基因的影响

以弱光敏感型番茄品种‘基尔斯’为试验材料,研究叶面喷施24–表油菜素内酯（EBR）对弱光胁迫下番茄幼苗生长、光合碳同化关键酶活性及基因表达的影响。结果表明,弱光胁迫下幼苗质量、茎粗和壮苗指数分别下降了70.5%、13.0%和77.7%,而株高增加了45.3%,说明外源EBR显著缓解了弱光胁迫对幼苗生长的抑制。弱光胁迫使番茄叶片净光合速率（P_n）降低42.8%,而喷施EBR后P_n提高到对照的72.0%。弱光胁迫导致番茄光合碳同化相关的核酮糖–1,5–二磷酸羧化/加氧酶（Rubisco）、果糖–1,6–二磷酸醛缩酶（Ald）、果糖–1,6–二磷酸酯酶（FBPase）和Rubisco活化酶（RCA）活性分别降低41.6%、31.3%、31.4%和19.6%,EBR处理后显著提高了这些酶的活性。同时弱光胁迫显著降低碳同化关键酶基因RbcL、RbcS、RCA、Ald、FBPase、SBPase、GAPDH、TK和PRK的表达量,而EBR显著提高这些基因的表达水平,其中SBPase和GAPDH的mRNA转录接近对照水平,TK和PRK的mRNA转录水平比对照提高了29%和37%。这些结果表明外源EBR通过调控弱光胁迫下番茄幼苗碳同化相关酶活性及其基因表达,提高叶片净光合速率,缓解弱光胁迫对植株的伤害,从而增强番茄幼苗的弱光耐性。     

Influence of patch,habitat, and landscape characteristics on patterns of Lower Keys marsh rabbit occurrence following Hurricane Wilma

Degradation of coastal systems has led to increased impacts from hurricanes and storm surges and is of concern for coastal endemics species. Understanding the influence of disturbance on coastal populations like the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) is important to understanding long-term dynamics and for recovery planning. We evaluated the effect of disturbance on the rabbits by determining which patch, habitat, and landscape characteristics influenced habitat use following Hurricane Wilma. We determined patch-level occurrence 6–9 months prior to Hurricane Wilma, within 6 months following the hurricane, and 2 years after the storm to quantify rates of patch abandonment and recurrence. We observed high patch abandonment (37.5% of used patches) 6 months after Hurricane Wilma and low rates of recurrence (38.1% of abandoned patches) 2 years after the storm, an indication that this storm further threatened marsh rabbit viability. We found the proportion of salt-tolerant (e.g., mangroves and scrub mangroves) and salt-intolerant (e.g., freshwater wetlands) vegetation within LKMR patches were negatively and positively correlated with probability of patch abandonment, respectively. We found patch size and the number of used patches surrounding abandoned patches were positively correlated with probability of recurrence. We suggest habitat use following this hurricane was driven by the differential response of non-primary habitats to saline overwash and habitat loss from past development that reduced the size and number of local populations. Our findings demonstrate habitat use studies should be conducted following disturbance and should incorporate on-going effects of development and climate change.     

Promoting pro-environmental gardening practices: Field experimental evidence for the effectiveness of biospheric appeals

Pro-environmental gardening practices can help to address climate change and biodiversity loss. However, little is known about how urban garden owners can be motivated to engage in such practices. In the present study, we tested the effectiveness of behavior change techniques for the promotion of pollinator-friendly garden flowers in a field experiment. Over a period of three weeks, we observed purchases of a pollinator-friendly seed mixture positioned in the checkout area of a Belgian wholesale store (total number of purchases = 162). Customers were exposed to posters that highlighted either the environmental benefits (e.g., conserving insect biodiversity) or the personal benefits (e.g., having a beautiful garden) of planting the seeds. In comparison to a control condition, seed purchases increased by 82% when environmental benefits were highlighted. The effect of stressing personal benefits was not significant. Our results indicate that pro-environmental gardening practices can be promoted by highlighting their environmental benefits at a point of decision.     

赤霉素对盐胁迫下樱桃萝卜种子萌发和 生长的影响

摘要：为探索缓解樱桃萝卜盐胁迫效应的化学调控措施,研究了NaCl（0、50、100、150 mmol/L）胁迫对樱桃萝卜种子萌发和幼苗生长的影响以及赤霉素（0、10、20、30、40 mg/L）对100 mmol/L NaCl胁迫的调控作用。结果表明：NaCl胁迫显著抑制了樱桃萝卜种子的萌发和幼苗生长,且NaCl浓度越大,抑制作用越强。在100 mmol/L NaCl处理下,种子发芽率、发芽势、发芽指数、活力指数、株高、单株鲜质量、根长、根表面积、根投影面积、根体积、根平均直径、根尖数、根分枝数、根系活力、叶绿素a含量、叶绿素b含量分别较对照显著降低4.33百分点、5.33百分点、30.05%、26.01%、20.88%、19.52%、50.08%、70.27%、70.83%、100.00%、23.08%、15.69%、22.73%、10.67%、12.86%、23.81%,过氧化氢 酶（CAT）活性较对照显著提高13.51%。在100 mmol/L NaCl胁迫下,采用30 mg/L赤霉素进行调控处理,樱桃萝卜的种子发芽率、发芽势、发芽指数、活力指数、根长、根表面积、根投影面积、根平均直径、根尖数、根分枝数、株高、叶绿素a含量、叶绿素b含量分别较对照显著提高4.78百分点、12.96百分点、23.09%、42.03%、108.44%、135.29%、140.00%、79.17%、15.45%、114.29%、15.38%、41.67%、70.00%,CAT活性则较对照显著下降33.33%,根系生长发育得到显著改善,株高和叶绿素含量均显著增加;但是当赤霉素浓度为40 mg/L时,效果开始减弱。说明低浓度赤霉素可以缓解盐胁迫对樱桃萝卜造成的抑制作用,但是浓度过高可能会造成新的胁迫,30 mg/L赤霉素是缓解樱桃萝卜盐胁迫的合适浓度。     

东北山樱根浸提液对幼苗生长和根系呼吸代谢的影响

以东北山樱(Cerasus sachalinensis Kom.)为试材,研究其根浸提液对幼苗生长及根系呼吸代谢的影响。结果表明,东北山樱根浸提液对幼苗株高、茎粗、发根数量、茎叶和根的生长量、根系活力、PSⅡ最大光化学效率及呼吸底物含量均表现出低促高抑的化感作用效果。100 g.L-1质量浓度处理对呼吸速率、呼吸途径、呼吸酶活性和中间代谢产物均无显著影响,呼吸代谢顺利进行;200 g.L-1质量浓度使呼吸速率显著升高,激活了HK、PK和G-6-PDH的活性,降低了MDH的表达量,TCA受到抑制,丙酮酸积累,幼苗表现出一定的逆境胁迫状态;400 g.L-1质量浓度使根系呼吸速率下降42.82%;G-6-PDH和6-G-PDH的活性显著提高,调控PPP大量运行,EMP-TCA受阻,丙酮酸和柠檬酸含量显著下降,幼苗呼吸代谢过程紊乱。     

不同茄子品种幼苗耐热性研究

以45 ℃/36 ℃（昼/夜）的温度对4个茄子品种进行胁迫处理,研究了高温胁迫对茄子的热害指数、电解质渗透率、SOD活性、MDA含量及叶绿素荧光参数的影响。结果表明,高温处理后,茄子热害指数、电解质渗透率及MDA含量显著上升,耐热品种上升幅度低于不耐热品种;SOD活性显著降低,恢复2 d后耐热品种06-E417和紫妃1号的SOD活性比处理前上升了20.3 %和20.7 %,不耐热品种则没有表现这种趋势。高温胁迫后,茄子Fv/Fm、Fv/Fo、ΦPSⅡ、qP、ETR及Fv’/Fm’均显著降低,耐热品种降低的幅度低于不耐热品种,表明在高温胁迫后耐热品种具有较高的光系统Ⅱ活性。     

Restorative effects of visits to urban and forest environments in patients with exhaustion disorder

This experimental study investigated differences in perceived restorativeness, mood, attention capacity and physiological reactions when visiting city and forest environments. Twenty female patients diagnosed with exhaustion disorder visited three different forest environments and one city environment in randomized order. They performed a standardized 90-min test procedure in each of these environments. Evaluation of the environments and psychological effects in mood were studied with self-administered questionnaires. Attention capacity was studied with Necker Cube Pattern Control task. Physiological responses were measured with regularly scheduled controls of heart rate and blood pressure, and a single test of heart rate recovery. Visits to the forest environments were perceived as significantly more restorative, enhancing mood and attention capacity compared to the city. This also applies to the results of heart rate and to some extent to the results of the diastolic blood pressure. The results from this experimental study support our hypothesis that short visits to forest environments enhance both psychological and physiological recovery and that visits to forest environments are likely to be beneficial when suffering from exhaustion disorder.     

干旱胁迫对砂糖橘树体营养的影响及其与成花的关系

 为了探讨干旱胁迫对砂糖橘（Citrus reticulata‘Shatangju’）树体营养的影响及营养与成花的关系,设置了不同干旱胁迫时间（0、2、4、6、8周）和不同氮素水平（每次每盆单独施N︰P₂O₅︰K₂O为15︰15︰15的复合肥5 g和另外加尿素6 g两水平）两因素进行盆栽试验研究。结果表明,干旱胁迫4周后树体氮素和钾素增加,而非结构性碳水化合物糖和淀粉呈下降趋势,磷素无明显变化,树体中C/N,P/N与对照相比降低。各养分含量及相互比率在干旱胁迫4周左右存在一个明显拐点,且与砂糖橘的成花时间表现高度一致。每枝成花数量和氮素及钾素有显著正相关关系,和C/N呈负相关关系,而和树体磷含量无显著相关关系。在正常供水情况下不同营养状况砂糖橘均未成花,但在干旱胁迫情况下氮素、钾素以及C/N和成花特性间有很好的相关关系。     

枸杞玻璃化组培苗恢复技术

以枸杞不同程度玻璃化组培苗为试材,采用组织培养法,研究了不同基本培养基、外源添加物、添加聚丙烯酰胺、改变培养条件及玻璃化苗脱水处理在玻璃化组培苗恢复中的作用,探索出最佳的枸杞玻璃化组培苗恢复方法。结果表明:1/2MS+6-BA 0.5mg·L^-1+活性炭0.5g·L^-1为枸杞轻度玻璃化苗恢复最佳培养基,适宜枸杞中度玻璃化苗恢复培养基为1/4MS+6-BA 0.5mg·L^-1+活性炭1.0g·L^-1。当添加聚丙烯酰胺8、16g·L^-1,枸杞轻度、中度玻璃化苗恢复率均达到最高,聚丙烯酰胺对枸杞玻璃化的组培苗有明显的逆转效果,逆转后的组培苗生长良好。经过脱水处理后,玻璃化苗明显得到恢复。脱水2d轻度玻璃化苗的恢复率可达77.61%。随着脱水的天数增加,枸杞中度玻璃化苗恢复率逐渐提高,当脱水天数达3d时,恢复率最高达71.24%。培养期间增强封口膜的透气性和光照强度能有效提高枸杞玻璃化苗恢复率。     

淹水对不同葫芦科作物叶绿素荧光特性的影响

在温室条件下,研究了根部淹水3d及淹水恢复3d后对黄瓜、丝瓜、苦瓜、黑籽南瓜叶绿素荧光参数的影响。结果表明,淹水对黄瓜、黑籽南瓜造成的胁迫最大,其光适应下初始荧光（F0’）、光适应下最大荧光（Fm’）、表观光合电子传递速率（ETR）、实际光化学量子产量（Yeild）、光化学猝灭系数（qP）显著降低,非光化学猝灭系数（qN）极显著升高;丝瓜表现为最耐淹水,苦瓜次之;淹水恢复3d后,黄瓜、黑籽南瓜的光系统II最大光化学效率（Fv／Fm）和其对照出现显著性差异,说明淹水对其光抑制的表现可能在恢复时才显现出来;试验中黄瓜恢复最慢,而黑籽南瓜恢复相对较快;淹水对黑籽南瓜胁迫较重可能和其处理时叶片数量较多有关。     

Influence of potassium humate on biochemical and agronomic attributes of bean plants grown on saline soil

To study the effect of soil application of potassium humate (KH) (0, 70 and 140 Kg ha^?1) on agronomic, biochemical attributes, and yield and its components on bean (Phaseolus vulgaris L.) cultivars ‘Bronco’ grown under two sites having different level of salinity (EC = 3.00 or 5.00 ± 0.20 dS m^?1). Two field trials were conducted at the Agriculture Test Station, Faculty of Agriculture, Fayoum University, in 2014 and 2015. The obtained results indicated that addition of KH increased all of the studied growth parameters, i.e. plant height, number of leaves, leaf area, stem diameter and canopy dry weight. Moreover addition of KH significantly increased membrane permeability measurements. KH significantly increased chemical composition related to salt tolerant either inorganic e.g. N, P, K, and decreased Na and Cl contents of leaves or organic components e.g. chlorophyll a + b, carotenoids, anthocyanin total phenolics, total flavonoids and proline. DPPH radical-scavenging activity and yield and its components were increased. The soil application of KH was found to be highly effective at improving the growth and yield of bean plants by alleviating the inhibitory effects of soil salinity stress.     

The association between plant diversity and perceived emotions for visitors in urban forests: A pilot study across 49 parks in China

Urbanization introduces uncertainties to the biodiversity of plant communities. The perception of biodiversity can be associated with positive mental health and well-being, but direct evidence is still insufficient. In this study, we collected data about plant biodiversity assessments from studies on urban forests in the literature of China’s national knowledge infrastructure. Records of the species amount, Shannon index, and Simpson index were extracted from 49 urban forest parks in 13 cities across mainland China from 2018 to 2021. A total of 1938 facial photos were obtained from microblogs with check-in locations at these parks in the Sina Microblog in 2020. Happy, sad, and neutral emotions and positive response index (PRI; happy minus sad) were rated and mapped for spatial distributions. The amount of species was distributed as a heterogeneous pattern for all plant types, and biodiversity was higher in the northern regions (e.g., ~55% in Qingdao and over 50% in Taiyuan) than in southern cities along the Yangtze River (e.g., ~35% in Huaihua and Changsha). Trees did not account for the association of biodiversity with emotional expressions. Smiles were elicited mostly in parks with more diverse shrubs (Shannon index: R=0.4335; P = 0.0029) and herbs (R=0.6162; P = 0.0008). Females showed more smiles than males (47% vs. 32%, respectively; F=39.15, P < 0.0001), and happy emotions tended to be higher in older visitors (senior vs. younger: 58% vs. 43%, respectively; F=2.72, P = 0.0280). Overall, we recommend visiting parks in northern cities of China for the benefit of evoking positive emotions through experiencing abundant undergrowth species. Female visitors would benefit more than males in the promotion of mental well-being by perceiving diverse shrubs and herbs in urban forest parks.     

Calcium starvation increases salt susceptibility in olive plants but has no effect on susceptibility to water stress

Summary

The responses of leaf water status, growth, and ion concentrations to water or to saline stresses were compared in olive cuttings of different Ca²⁺ status. Mist-rooted ‘Picual’ olive cuttings were grown in a greenhouse in 2 l plastic pots containing perlite. A nutrient solution with or without 2.5 mM CaCl₂ was initially used to irrigate the plants. When the Ca²⁺-starved plants differed in height from the Ca²⁺-treated plants, water or saline stress (i.e., no irrigation or 75 mM NaCl, respectively) were applied. The results indicated that Ca²⁺ increased growth in saline-treated plants, but not in water-stressed plants. After 98 d growth, the stresses were relieved and the plants were irrigated again with or without Ca²⁺. Growth increased and leaf water status was increased during this recovery period, but no direct effects of Ca²⁺ were observed in the response of plants to stress-relief. We suggest that the beneficial effect of Ca²⁺ on tolerance to salt stress in olive plants was related to protection against Na⁺ toxicity, because there was no response of water-stressed plants to the supply of Ca²⁺.