生根粉在华北落叶松造林中的应用技术研究

用 ２５、５０、１００ｕｇ／ｇ 的 Ａ Ｂ Ｔ 生根粉３ 号浸泡华北落叶松苗木根系４ｈ 后造林,结果表明,生根粉在华北落叶松造林中效果明显,用５０ｕｇ／ｇ 生根粉浸根可使造林成活率提高１０ 个百分点,用 ２５ｕｇ／ｇ 浸根可使苗木生物量、苗高和地径分别提高３８．２％ 、７．３％ 和１８．８％ 。     

ABT生根粉对樟子松生长季造林翌年保存率和高生长的影响

用不同浓度的ＡＢＴ生根粉３号、氯化钠、ＡＢ－抗旱剂、吸水剂处理樟子松苗木后进行生长季造林。其结果表明，这几种药剂均可提高樟子松生长季造林翌年保存率，但以ＡＢＴ生根粉３号溶液浸根和以其溶液制成的泥浆效果最好。ＡＢＴ生根粉３号还可以提高樟子松生长季造林，翌年苗木的高生长量和发根量。     

樟子松夏季造林试验

樟子松夏季造林试验戴继先（河北省塞罕坝机械林场，围场０６８４６６）樟子枯春季造林因干旱多风成活率不高，而在夏季造林又因苗干针叶和根系的生理萎蔫，使光合产物少，苗木发根少，当年苗木虽然成活，但翌年大量死亡。为此，作者采用三因素正交试验法，对樟子松夏季造...     

ABT生根粉对樟子松生长季造林翌年保存率和高生长的影响

用不同浓度的ＡＢＴ生根粉３号，氯化钠，ＡＢ－抗旱剂，吸水剂处理樟子松苗木后进行生长季造林。共结果表明，这几种药镁可提高樟了松生长季造林翌年保存率，但以ＡＢＴ生根粉３号溶液浸极和以其溶液制成的泥浆效果最好。ＡＢＴ生根粉，３号还可以提高樟子松生长季造林，翌年苗木的高生长量和发根量。     

杨树苗木等级对造林后期生长的影响

采用什么等级的杨树苗木造林，在不同国家和地区有很大差异。其原因既有传统习惯问题，也有因自然条件或无性系特性不同而得出的结论。本试验目的是为了确定欧美杨（奈瓦）和欧美杨１—７２两个无性系，３～４个苗木等级，在淮北市粉煤灰复垦地上，造林后４年间的生长表现。结果表明，用欧美杨（奈瓦）大苗造林（２／３或１／２苗）有明显的缓苗现象；用小苗造林（１／１笛），到第２年末，便消除了与大苗林木的高、粗生长差异。用不同等级的１—７２杨苗木造林，缓苗情况差异不大，因此，用大苗造林的林木生长量到第４年仍然领先于用小苗造林的生长量。     

苗龄对樟子松造林成活率的影响

在干旱沙地和沙丘上分别对２年生、３年生、４年生、５年生的樟子松苗木进行造林试验，结果表明，４年生苗木生长最好，３年生苗木最差，２年生苗在有植被覆盖的沙地上造林，优于３年生苗，可保持在８０％以上的造林成活率。     

杨树苗木等级对造林后期生长的影响

采用什么等级的杨树苗木造林，在不同国家和地区有很大差异。其原因既有传统习惯问题，也有在自然条件或无性系特性不同而得出的结论。本试验目的是为了确定欧美杨（奈瓦）和欧美杨Ｉ－７２两个无性系，３－４个苗木等级，在淮北市粉煤灰复垦地上，造林后４年间的生长表现。结果表明，用欧美杨（奈瓦）大苗林（２／３或１／２苗）有明显的缓苗现象：用小苗造林（１／１苗），到第２年末，便消除了与大苗林木的高、粗生长差异。用不同     

长江下游滩地柳树无性系造林经营技术研究

根据长江滩地立地条件,试验分析了低湿滩地苏柳无性系人工林密度效应,不同规格苗木造林后期生长情况,插干、修枝、施肥的效果。由此提出推广滩地柳树插干造林,造林密度 低于１６７７株／ｈｍ＾２,造林苗高２．５－３．５ｍ和要因地施肥等造林、经营措施。     

长江下游滩地柳树无性系造林经营技术研究

根据长江滩地立地条件,试验分析了低湿滩地苏柳无性系人工林密度效应,不同规格苗木造林后期生长情况,插干、修枝、施肥的效果。由此提出推广滩地柳树插干造林,造林密度不应低于１６７７株／ｈｍ２,造林苗高２．５ｍ～３．５ｍ和要因地施肥等造林、经营措施。     

樟子松苗木培育方法的研究

经３年试验表明．樟子松１—１苗木的地径、苗高生长均达到了辽宁省林木育苗技术规程标准，造林平均成活率在８４％，应以株行距５～８×１０～１５ｃｍ移植，比培育３年生苗木提高圃地利用率，是培育造林苗木的主要方法。从５种密度切根不移植培育２年生苗木的试验看出，造林平均成活率达８８．８％，最高为９５％，以１２５～１５０株／ｍ２密度培育．转培育１一１苗省移植工序．是培育造林苗较理想方法。比１年生苗剪根保留１５ｃｍ和２０ｃｍ根长，培育１—１苗木为佳。     

3种方法培育杨大苗试验

通过采用留植、移植、剪根移植3种不同方法培育杨大苗的试验,结果表明:3种方法培育的杨大苗质量有明显区别。留植苗在苗高、地径上有优势,但根系不好,侧根数少,主侧根过粗,起苗时易造成机械损伤,造林不易成活;而移植苗较留植苗质量有所改善,侧根数增多,起苗时机械损伤较少,造林易成活;最好的是剪根移植苗,克服了以上2种方法所有弊病,苗木质量优良,造林成活率高。     

Ice nucleation and frost resistance of Pinus canariensis seedlings bearing needles in three different developmental states

Frost resistance and ice formation in different developmental states of needles of P. canariensis seedlings were assessed. Regrowth after frost damage was used to determine the overall frost survival capacity. Two distinct freezing exotherms (E1, E2) were registered. E1 was between ?1.7 and ?2.0 °C. Initial frost damage (LT₁₀) was 1.5–2.7 °C below E1. E2 was between ?5.6 and ?6.0 °C, and either corresponded with LT₅₀ or occurred in between LT₁₀ and LT₅₀. Current year needles were less frost resistant than 1-year-old needles. The overall recuperation capacity of seedlings revealed that frost survival may be underestimated when only needle damage is assessed. Freezing of seedlings with or without roots had no effect on the frost resistance of needles but recuperation capacity was significantly affected. Seedlings survived ?10 °C during summer indicating that they withstand the lowest naturally occurring frosts in Tenerife.     

赤松毛虫幼虫单体食叶量数学模型的研究

本文采用单体饲养的方法,测定了赤松毛虫幼虫单体在各龄的食叶鲜重和长度,用指数模型、幂函数模型、复合指数模型对幼虫单体食叶量进行了拟合,并进行了拟合优度比较,得出幼虫单体食叶鲜重(W)和食叶长度(L)的最优拟合数学模型。     

Nitrogen availability modifies the ozone responses of Scots pine seedlings exposed in an open-field system

Three-year-old Scots pine (Pinus sylvestris L.) seedlings were exposed to either ambient or elevated (1.5-1.6 x ambient) ozone concentration ([O3]) for three growing seasons in an open-field fumigation facility where they were irrigated during the growing season with a nutrient solution providing nitrogen (N) at 70 (LN treatment), 100 (control) or 150% (HN treatment) of the optimum supply rate. Treatment effects were most evident during the third year of exposure, when the ambient [O3] + HN treatment enhanced whole-plant biomass, root/shoot dry weight ratio, needle pigment concentrations and the number of chloroplast plastoglobuli in the mesophyll cells in current-year (C) needles, whereas it reduced starch accumulation in C needles and abscission of 2-year-old (C+2) needles. In the control fertilization, 3 years of exposure to elevated [O3] decreased stem-base diameter and increased K concentration and electron density of chloroplast stroma in C needles. Plants in the HN treatment exposed for 3 years to elevated [O3] had significantly lower heights, current-year main shoot length and root/shoot dry mass ratio than control plants, and increased abscission of C+2 needles. In contrast, O3-induced changes in the ultrastructure of mesophyll cells were most evident in seedlings grown for 3 years in the LN treatment. We conclude that, in Scots pine, a relatively O3-tolerant species, chronic O3 exposure leads to cumulative growth reduction, increased needle abscission and changes in carbon allocation that are strongly influenced by plant N availability.     

Early season short-day treatment did not affect the field performance of Pinus sylvestris container seedlings in summer planting

Abstract

When Scots pine (Pinus sylvestris L.) seedlings are short-day (SD) treated in May or early June, height growth ceases but seedlings reflush within a few weeks and grow secondary needles (later referred to as early SD treatment). These “2-year-old-like” seedlings have been thought to be more stress tolerant than traditional 1-year-old pine seedlings, and thus suitable for summer and autumn plantings. To test this, seedlings sown in April were early SD treated over a 3-week period from the beginning of June and the seedlings were planted at 10-day intervals from the beginning of July until the end of September, and also during the following spring. Neither survival nor height growth of early SD-treated seedlings differed from untreated (1-year-old) seedlings. Moreover, for both early SD-treated seedlings and 1-year-old seedlings, those planted in summer grew and survived better after planting but had more multiple leaders than seedlings planted in autumn or spring.     

Photosynthesis in Norway spruce seedlings infected by the needle rust Chrysomyxa rhododendri

Chrysomyxa rhododendri (DC.) De Bary is a needle rust with a host shift between Rhododendron sp. and Norway spruce (Picea abies (L.) Karst.), penetrating only the new developing flushes of the conifer. Because little is known about its effects on trees, we investigated several parameters related to photosynthesis in artificially infected 3-year-old Norway spruce seedlings. The potential efficiency of photosystem II (PSII; derived from chlorophyll fluorescence measurements) was reduced in infected current-year needles as soon as disease symptoms were visible, about three weeks after inoculation. Two weeks later, photosynthetic O(2) evolution (P(max)) of infected needles was less than 20% of control needles, whereas respiratory O(2) uptake (R(D)) was about three times higher than that of control needles. Nonstructural carbohydrate concentrations were about 60% of control values in all parts of the shoots of infected trees. Photosynthetic inhibition was associated with marked decreases in chlorophyll concentration and chlorophyll a/b ratio but only a small reduction in carotenoid concentration. In infected trees, P(max) of noninfected 1-year-old and 2-year-old needles was 50 and 80% higher than in the corresponding age class of needles of control trees. Estimation of potential daily net dry mass production, based on P(max), R(D), specific leaf area, carbon content and needle biomass, indicated that seedlings infected once were able to produce 60%, and those infected twice only 25%, of the dry mass of controls. We conclude that afforestation and regeneration of Norway spruce is seriously impaired in regions where seedlings are frequently attacked by Chrysomyxa.     

Effects of complex stress of chronic acid fog exposure with rhizosphere aluminum on nutrient status in Abies firma seedlings

We exposed momi fir (Abies firma Sieb. et Zucc.) seedlings to simulated acid fog of pH 3.0 for about 3 years (from July 1999). During the last year of acid fog exposure, half of the seedlings were subjected to rhizosphere Al stress (complex stress) and the nutrient status of seedlings was determined. Chronic acid fog exposure decreased Fe and Zn concentrations in current-year and 1-year needles, and Al in 1-year needles, but had little effect on major element concentrations. Aluminum treatment had a broad impact on nutrient status in fine roots and needles. In fine roots, increases in Al and Cu concentrations and decreases in B, Mn, and Zn concentrations were observed. In 1-year needles, Al treatment increased Al, B, and Mn concentrations and decreased Cu concentration. The complex effect of acid fog with aluminum on nutrient status was relatively slight. These results show that changes in nutrient status under chronic acid fog exposure and/or Al stress are induced before the decline of photosynthesis in momi fir seedlings, mainly due to Al stress.     

土壤干旱胁迫对樟子松针叶膜脂过氧化、膜脂成分和乙烯释放的影响

本文采用对盆栽樟子松苗木进行土壤干旱胁迫处理的办法,研究其针叶ＳＯＤ活性水平、ＭＤＡ含量以及膜脂成分和乙烯释放量的变化。结果表明：随着干旱胁迫的加强,ＳＯＤ活性呈现先上升后下降的趋势,ＭＤＡ含量逐渐上升到最高水平,在严重干旱末期下降,但仍处于高水平;ＩＵＦＡ在严重干旱胁迫下开始下降,乙烯伴随着ＩＵＦＡ水平明显的下降而产生,同时苗木走向死亡。这些结果表明樟子松针叶受土壤干旱胁迫,酶促保护系统破坏导致     

叶型对马尾松幼苗生长及叶绿素荧光特征的影响

【目的】研究叶型对马尾松幼苗生长及叶绿素荧光特征的影响,以期为马尾松苗木选择及栽培提供参考。【方法】以出圃时呈现为全初生条形叶、全次生针形叶和中间型的马尾松1年生幼苗为试验材料,分析其生长指标、光合色素含量及叶绿素荧光参数,研究初生叶和次生叶叶绿素荧光特征差异及对幼苗生长的影响。【结果】全次生叶幼苗出圃时苗木质量指数(QI)、干物质积累量及造林1年后净生长量均显著高于全初生叶幼苗;次生叶的叶长、体积和表面积等指标均显著大于初生叶;初生叶中叶绿素a、叶绿素b和总叶绿素含量均显著高于次生叶,两者间的类胡萝卜素含量无显著差异。初生叶的F_m、F_v/F_m、F_v/F_o均显著高于次生叶,F_o在2种叶型间无显著差异;初生叶的PSⅡ反应中心参数Y(Ⅱ)和F_v’/F_m’、淬灭参数q_P和NPQ、能量耗散参数Y(NPQ)和Y(NO)及光响应参数ETR_max、α、β和I_k也均高于次生叶,在高光强条件下,初生叶的非光化学淬灭和调节性能量耗散能力增强。由于次生针叶叶长、体积和表面积等形态指标均显著大于初生叶,因而具有次生针叶的幼苗的光合作用面积更大,干物质量积累较多,出圃时的苗木质量以及造林后的生长表现均高于全初生叶的幼苗。【结论】与次生叶相比,初生叶拥有较高的叶绿素含量,较耐光抑制,有较高的光能转化效率,但高光强条件下会通过热耗散的形式来减少多余光能对光合系统的损害;拥有次生叶的幼苗表现出较好的苗木质量及生长特性。     

Paclobutrazol affects the resistance of black spruce to high light and thermal stress

Detached needles from 20-week-old black spruce (Picea mariana (Mill.) B.S.P.) seedlings root-drenched with 60 mg of paclobutrazol were exposed to two temperatures (22 and 50 degrees C) and two light treatments (100 and 1900 &mgr;mol m(-2) s(-1) PAR) in a factorial combination for 4 h in vitro. Mean dry weights of individual needles from paclobutrazol-treated plants were approximately 1.9 times heavier than that of needles from untreated controls at 22 degrees C, but no differences were observed following incubation at 50 degrees C. Numbers of cells per needle remained constant in all treatments. Chlorophyll and carotenoid contents per needle were higher in seedlings treated with paclobutrazol than in untreated control seedlings, and the differences were most pronounced in the high temperature plus high light treatment. In low light at 50 degrees C, quantum efficiency of photosystem II was 45% higher in needles of paclobutrazol-treated seedlings than in needles of untreated control seedlings, but quantum efficiency of needles from treated seedlings declined when needles were exposed to high light at either temperature. Peroxidase and superoxide dismutase activities were up-regulated by paclobutrazol, whereas catalase activities were depressed and no significant differences were observed between treated and control needles at 50 degrees C in either light treatment. Paclobutrazol treatment did not moderate the depressive effects of high temperature on total soluble protein or on the activity of ribulose-1,5-bisphosphate carboxylase. In contrast, high activities of phosphoenolpyruvate carboxylase were maintained in paclobutrazol-treated needles under all stress conditions, whereas large losses in activity were recorded in untreated needles at 50 degrees C. Collectively, these observations suggest that paclobutrazol treatment may convey resistance to excessive light and high temperatures by increasing the potential of conifers to limit damage caused by oxidative stress.