Reflectance features of water stressed Larix gmelinii needles

In recent years, Xing’an larch (Larix gmelinii) has been seriously infected by pests and drought. In order to improve the accuracy of monitoring the damage to larch by remote sensing (RS) and to predict the health of the larch, we studied the reflectance features of larch needles under different water conditions at the needle level by using the LIBERTY (Leaf Incorporating Biochemistry Exhibiting Reflectance and Transmittance Yields) model. Before applying the LIBERTY model, we recalibrated it for the needles of L. gmelinii based on ten field-measured spectral curves. After recalibration, LIBERTY can accurately model the needle reflectance spectra of L. gmelinii. Based on the recalibrated LIBERTY model, we extracted and analyzed the sensitive bands to needle water content by simulating the needle reflectance spectra under different drought conditions. Then, we established mathematical equations between the spectral indices (MSI, NDWI, and GVMI) and needle water content. Results show that the variations of larch needle water content can significantly change the needle spectra at the near-infrared and short-wave infrared bands. The higher the water content is, the higher the absorption peak is. We believe that our study will provide the theoretical basis and an optional method to investigate the forest water stress using multi-spectral or hyper-spectral remote sensing data.     

外源茉莉酸类化合物对2种落叶松针叶内单宁含量的影响

为明确外源茉莉酸类化合物对落叶松防御物质单宁的诱导作用,利用喷雾处理和香草醛比色测定法,研究不同浓度外源茉莉酸类化合物对2年生兴安落叶松和长白落叶松的诱导作用,及对其针叶内单宁含量变化的影响。喷施茉莉酮(ZJ)、茉莉酸甲酯(MJA)和茉莉酸(JA)后,2种树体针叶内单宁含量增加或减少波动明显,诱导作用可持续10～20天。茉莉酮对兴安落叶松针叶内单宁含量变化的影响较茉莉酸甲酯和茉莉酸显著;但3种茉莉酸类化合物均明显影响长白落叶松针叶内单宁含量的变化。0.01mmol·L-1茉莉酮、茉莉酸甲酯和1mmol·L-1茉莉酸诱导兴安落叶松针叶内单宁含量明显变化;0.01mmol·L-1茉莉酸甲酯和1mmol·L-1茉莉酸对长白落叶松针叶内单宁含量变化影响显著。3种茉莉酸类化合物诱导兴安落叶松针叶内单宁含量的变化幅度高于长白落叶松。总之,喷施外源茉莉酸类化合物能够诱导落叶松针叶内单宁含量系统增加或减少,并具持效性;2种落叶松对外源茉莉酸类物质的应激反应不同,兴安落叶松的应激反应强度大于长白落叶松。     

Growth and photosynthetic traits of hybrid larch F1 (Larix gmelinii var. japonica x L. kaempferi) under elevated CO2 concentration with low nutrient availability

The hybrid larch F(1) (Larix gmelinii var. japonica × Larix kaempferi) is considered one of the most important tree species not only for timber production but also as an afforestation material for severe conditions such as infertile soil. To predict the ability of hybrid larch F(1) as an afforestation material under potential climates in the future, it is important to understand the response of hybrid larch F(1) to elevated CO(2) concentration ([CO(2)]) under low nutrient availability. Three-year-old seedlings of hybrid larch F(1) were grown under two different levels of [CO(2)], 360 (ambient) and 720 μmol mol(-1) (elevated), in combination with two different levels of nitrogen (N) supply (0 and 30 kg ha(-1)) for one growing season. Elevated [CO(2)] reduced the maximum rates of carboxylation and electron transport in the needles. Net photosynthetic rates at growth [CO(2)] (i.e., 360 and 720 μmol mol(-1) for ambient and elevated treatment, respectively) did not differ between the two CO(2) treatments. Reductions in N content and N use efficiency to perform photosynthetic functions owing to the deficiency of nutrients other than N, such as P and K, and/or increase in cell wall mass were considered factors of photosynthetic down-regulation under elevated [CO(2)], whereas stomatal closure little affected the photosynthetic down-regulation. Although we observed strong down-regulation of photosynthesis, the dry matter increase of hybrid larch F(1) seedlings was enhanced under elevated [CO(2)]. This is mainly attributable to the increase in the amount of needles on increasing the number of sylleptic branches. These results suggest that elevated CO(2) may increase the growth of hybrid larch F(1) even under low nutrient availability, and that this increase may be regulated by changes in both crown architecture and needle photosynthesis, which is mainly affected not by stomatal limitation but by biochemical limitation.     

CAUSES OF OUTBREAK OF THE LARCH CATERPILLAR(Dendrolimus superans Butler) IN DAXINGAN MOUNTAIN AND ITS CONTROL STRATEGY

Inl99o,intheDaxinganMountainfOrestregion,anoutbreakoflarchcaterpil1aroccurredona1argeareaofmorethanonemillionh.2,mainlydistributinginEighteenthStationForestryService,HumaCounty,HanjiayuanForestryServiceandotherForestryServices'Song1ing,Tahe,andAmuer.Duringl99o-l992,wesystematicallysurveyedthesituationoftheoutbreakofthelarchcaterpil1arandc0ntr0llingmeasuresweretaken,sothatitsdamagewaseffective1yc0ntrol1ed.THESITUATIONOFTHE0UTBREAK0FLARCHCATERPILLARINDAXINGANM0UNTAIN…     

Causes of outbreak of the larch caterpillar (Dendrolimus superans Butler) in Daxingan Mountain and its control strategy

In 1991, in Daxingan Mountain, an outbreak of larch caterpillar (Dendrolimus superans Butler) happened on large areas of more than one million hectares, where stands of larch were seriously damaged because needles on the trees were almost eaten up by the pest, causing enormous economic losses. Analysis of data collected indicated that the main cause of the outbreak of larch caterpillar on large areas was that, after thirty years of exploitation, mature and overmature forests decreased rapidly, middle-aged and young forests incresed in large amount, significant changes occurred in individual ecological conditions of stands, especially those tended, with decreasing canopy density and better light condition in the forest, and all these were adventageous to the outbreak of the pest. In addition, in recent years, the climatic condition in Daxingan Mountain changed significantly. The yearly average temperature raised gradually and the soil surface temperature in April and October increased year by year, which were advantageous to the outbreak of larch caterpillars. In short, the significant changes in the ecological conditions in Daxingan Mountain provided suitable conditions for the outbreak of the larch caberpillar, and after several years of increase in population number, the larch caterpillar outbroke into a serious disaster on vast areas. In the paper, composite control strategy was also discussed.     

松苗立枯病的无公害防治技术

利用泡底土、非耕作层土、草炭、落叶松干叶混锯末、牛粪水5种材料做覆土盖种的试验结果表明，防治樟子松苗立枯病效果最好的是松干叶混锯末小区，其次是泡底土小区；防治红松苗立枯病效果最好的是泡底土小区，其次是草炭小区。同时，这几种覆土材料对苗木的苗高、地径生长都有一定的促进作用。     

Activities of some defense proteins associated with age or plant family in larch needles of <Emphasis Type="Italic">Larix olgensis</Emphasis> and <Emphasis Type="Italic">L. kaempferi</Emphasis> × <Emphasis Type="Italic">L. gmelinii</Emphasis>

Defence proteins are a kind of chemical defence compounds. They play a key role in plant restraining biotic and abiotic harm. To illuminate activities of some defense proteins associated with age or plant family of larch, the larch needles were collected from two different families of Korean larch, Larix olgensis and a hybrid larch, L. kaempferi × L. gmelinii, respectively, and then the activities of defence proteins in those were tested using a UV spectrophotometry. The results showed that the activities of protective enzymes at the16-/17- and 19-year-age groups were higher than those at the other age groups in the both larch species. While the activities of polyphenol oxidase (PPO) at the 16-/17-year-age group and phenylalanine ammonia-lyase (PAL) and protease inhibitors at the 19-year-age group were the highest among all age groups. Then, compared with L. olgensis, the hybrid larch had significant effects on the activities of protective enzymes. The effects of plant family on the activities of PAL and chymotrypsin inhibitor were significantly different, and then those on the activities of PPO were not significantly different. The effects of the two families in L. olgensis on the activities of trypsin inhibitor (TI) were significantly different, while those in the hybrid larch on the activities of TI were contrary. To conclusions showed that the different age and plant family significantly affected the activities of defence proteins in the needles of two larch species, and then enhanced the larch resistance to pests. These could play a key function in forestry tree genetic improvement and management in future.     

Zur Pathologie einer Cytoplasmapolyedrose bei der Nonne (Lymantria monacha L.) in Abhängigkeit von der Nahrungspflanze

The virulence of a cytoplasmic-polyhedrosis virus (CPV) to the nun moth (L. monacha) depended on different food plants. Virus infected larvae fed with pine needles showed very serious symptoms like high mortality, delay of development and characteristic deformations of the pupae. The reactions of infected larvae were much lower on spruce. The lowest susceptibility could be observed, when larvae were reared on larch needles.     

结实量对兴安落叶松和长白落叶松针叶内游离氨基酸含量的影响

研究不同种类落叶松结实量与其抗性的关系,采用柱前衍生高效液相色谱法检测分析兴安落叶松和长白落叶松在不同结实等级情况下针叶内游离氨基酸含量变化.结果表明:兴安和长白落叶松针叶内含有17种游离氨基酸,虽然苯丙氨酸在2种落叶松内均为优势氨基酸,但2种落叶松针叶内的多种与抗性相关的游离氨基酸含量存在较大差异;兴安落叶松针叶内丙氨酸、精氨酸、谷氨酸、异亮氨酸、赖氨酸、苯丙氨酸和缬氨酸含量在不同结实等级间存在较大差异,长白落叶松针叶内天门冬氨酸和苯丙氨酸含量在不同结实等级间存在较大差异;兴安落叶松针叶内天门冬氨酸含量显著小于其在长白落叶松针叶内含量;当结实较少时,2种落叶松针叶内游离氨基酸总量,显著低于其他3个结实等级的游离氨基酸总量,结实较多时,针叶内游离氨基酸总量最高.说明结实量大小直接影响落叶松针叶内的资源分配,进而改变其对植食昆虫的适口性及抗性,种类间的差异对落叶松具有同样的影响.     

Environmental control of ozone uptake in Larix decidua Mill.: a comparison between different altitudes

We studied ozone (O(3)) uptake by European larch (Larix decidua Mill.) needles under ambient conditions at both a low and a high elevation site. At a given ambient O(3) concentration, the rate of O(3) uptake by needles was effectively controlled by stomatal conductance and, hence, by factors such as light, humidity and water status, which control stomatal conductance. At both study sites, atmospheric water vapor pressure deficit (VPD) was the climatic factor most closely correlated with ambient O(3) concentration. Thus, when ambient O(3) concentrations were highest, O(3) flux into the needles tended to be restricted by narrowing of the stomata. Mitigation of potential O(3) stress by stomatal closure was most marked at the low elevation site where both soil water stress and atmospheric VPD were greater than at the high elevation site.     

Endophytic fungi in Siberian larch (Larix sibirica) needles

Endophytic fungi were isolated from surface‐sterilized needles of the Siberian larch. Samples were collected from a native growing site of the Siberian larch in north‐western Russia and from sites in Russia, Finland and Iceland where the Siberian larch has been introduced. The isolated fungi were classified to operational taxonomic units (OTUs) using colony morphology and molecular characteristics. Needle colonization rates were 50–99% and in total 79 OTUs were found. There were five common OTUs, which covered 86.2% of all isolates. The most common OTU lacked from the youngest plantations in Finland (Solböle) and in Iceland (Kjarnaskógur). The highest similarity in regard to the frequency of OTUs occurred among the stands established long ago in Finland, and the UPGMA clustering using similarity indices separated the seven stands into two major groups.     

Enhanced seed production and metabolic alterations in Larix leptolepis by girdling

The demand for Japanese larch (Larix leptolepis) seeds has increased in Korea but their supply has been limited due to sporadic natural seed production. Among the various flower induction techniques, girdling woody stems has been recognized as a simple and efficient method to enhance seed production in a number of conifers. In this study, stem girdling was applied to 42-year-old Japanese larches, resulting in remarkable enhancement of seed cone production with no morphological changes in the seed characteristics. Metabolic alterations in needles of the girdled and the control trees were interrogated by using 23 individual metabolites including soluble sugars, polyamines and amino acids. In the girdled trees, the contents of both soluble sugars and polyamines were higher from June to July and then became similar to those in the control. The levels of amino acids were significantly increased only in August by girdling compared to the non-girdled trees. In control larch trees, the dominant amino acids were changed from Glu and Ala until July to Asp and Tyr in August. Interestingly, the concentrations of Asp-derived amino acids such as Lys, Met and Thr, were increased by girdling and they also showed significant correlations with the number of seed cones per trees, suggesting that the enhanced levels of three amino acids might positively influence on the development of seed cones in girdled larch trees. Although the role of Asp-derived amino acids on enhanced seed cone production remains unclear, the approach presented in this study might provide useful information in elucidating metabolic network modulation induced by girdling and will be further applied for enhanced seed cone production in Japanese larch trees.     

Comparative analysis on the litter in Korean pine Mongolian scots pine and dahurian larch plantations (I) Amount and fluctuation of litter fall

Investigations were made in korean pine, mongolian scots pine and dahurian larch plantations in Laoshan Plantation Experiment Station of Maoershan Experiment Forest Farm of Northeast Forestry University. Data are tabulated on the amount and seasonal and annual fluctuations of fractional composition of the litter (conifer needles, branches, cones, bark scales, broad leaves) in the three plantations. The accounts of conifer needle branch and bark scale litter are as follows: korean pine: 71.16%, 6.23% and 7.32%; mongolian scots pine: 43.65%, 18.52 % and 32.12%; dahurian larch: 90.30%, 7.83% and 1.85%. There are certain broadleaf litter in dahurian larch and mongolian scots pine plantations (account for 7.61% and 8.92% respectively). The litter wither and fall concent ratively in autumn in dahurian larch plantation and scattered all year long in korean pine and mongolian scots pine plantations. Along with the increase of stand age, the absolute amount of litter tend to increase, the relative amount of main fractional compositions (conifer needle, branch and bark scale) in korean pine and mongolian Scots pine plantations maintain stead, whereas in dahurian larch plantation, the relative amount of conifer needle is decreased gradually and the relative amount of other fractional compositions are increased gradually.     

Frost hardening in first-year eastern larch (Larix laricina) container seedlings

Eastern larch (Larix laricina [du Roi] K. Koch) container seedlings were tested to determine shoot frost hardiness development under short or long days and warm (15 to 25 °C) or cool (10/5 °C, day/night) temperatures, to aid in the development of greenhouse hardening strategies. Seedlings were sampled sequentially over time (25 seedlings per week) from a population of 1000 trees. Frost hardiness increased significantly after one week of fluctuated over the next 6 weeks, and increased thereafter through week 14. Seven weeks of warm, intermittent short days, followed by 6 weeks of cool, continuous short days, resulted in greater frost hardiness than 13 weeks of warm, intermittent short days. In contrast, seedlings exposed to 7 weeks of warm, intermittent short days, followed by six weeks of warm, long days were significantly less frost hardy. Stems with needles attached had lower Index of Injury than stems without needles.     

COMPARATIVE ANALYSIS ON THE LITTER IN KOREAN PINE MONGOLIAN SCOTS PINE AND DAHURIAN LARCH PLANTATIONS(Ⅰ) AMOUNT AND FLUCTUATION OF LITTER FALL

Koreanpine(Pinuskoraiensis)(KP),mongolianscotspine(Pinussylvestrisvarmongolica)(MSP)anddahurianlarch(LarisgmeIinii)(DL)arethemainconiferousspeciesforforestationinnortheastregionofChina-LargeareplantationsofKP,MSPandDLhavebeenplantedintheregionsincel95o's.Whetherthestandstabilityandecolo-gicalequilibriumcanbemaintainedandtheforestfloorproductivitycanincreaseintheplantati0nsismainlydeterminedbytheamount,fracti0nalandchemicalcomp0sitionanddecomp0sitionrateof1itters,exceptforinfluenceofl0ca…     

Distribution of the larch brown rust caused byTriphragmiopsis laricinum (Uredinales) in Russian Far East

The larch brown rust caused byTriphragmiopsis laricinum was found onLarix cajandri in Primorsky Territory, Russia. This was a new host and locality record for the pathogen. Preliminary survey of the disease incidence in several localities in East and Northeast Russia and Yakutia-Sakha Republic indicated the restricted distribution of the rust in a few localities in Primorsky Territory. As previously reported in China,T. laricinum was proved to form uredinia in nature and to be able to propagate vegetatively by urediniospores. This suggests the fungus could become a devastating pathogen threatening a large-scale larch plantation in Far East of Russia. Field observations and the failure of basidiospore inoculation onto larch needles suggest the heteroecious life cycle ofT. laricinum.     

Root secretion stimulating ash growth in larch-ash mixed forest

IntroduchonRePOrt6d as early as 1920s, the groWth of ashcould be increaSed as ash was mixed with larch.However, the mechanism of allelopathic effect betwedn larch and ash has not been clearly yet. Theallelopathic ~ in mixed forest were generallyregard6d as fOllowing four wayst volatile matt6rs, rootsecredon, St6m leaching, and litter decompositionmatt6rs (Zhai 1993). This paper presented the studies on the ~ of root secretion, focused on thosestimulahon allelochemicals that can increase the…     

日本落叶松 UDPGDH基因的cDNA克隆和表达分析

以日本落叶松杂交Solexa转录组测序获得的数据为依据,经拼接后获得尿苷二磷酸葡萄糖脱氢酶(UDPGDH)原序列,以该序列两端设计引物,在落叶松亲代和子代幼嫩针叶中成功克隆了UDPGDH基因cDNA序列,序列长1 443 bp,编码480个氨基酸。qRT-PCR结果分析表明:UDPGDH基因的表达量在落叶松杂交子代中远远高于亲本,正交子代的表达比反交子代高,说明UDPGDH在形成细胞壁半纤维素前体物过程中起着非常重要的作用,暗示UDPGDH在子代的高表达有利于杂种优势的形成。     

Fall fertilization enhanced nitrogen storage and translocation in Larix olgensis seedlings

Fall nutrient loading of deciduous forest nursery seedlings is of special interest because of foliage abscission and varied translocation patterns. For non-deciduous seedlings in the nursery, fall fertilization typically can reverse nutrient dilution and possibly increase nutrient reserves; however, this technique has received little attention with deciduous conifer trees that translocate nutrients before abscising foliage. We evaluated how fall nitrogen (N) fertilization affected N storage and translocation in the deciduous conifer Olga Bay larch (Larix olgensis Henry) seedlings during the hardening period. Seedlings were supplied with 25 mg N seedling^?1 for 15 weeks before hardening and fall fertilization treatments began with a three week application period of K¹⁵NO₃ at 0, 5, 10 and 15 mg N seedling^?1. During the hardening period, fall N fertilization had little effect on seedling morphology. The N concentration and content of needles decreased dramatically as needles abscised, while that of stems and roots increased. Six weeks after fall N fertilization ceased, all seedlings translocated similar net N from their needles. For the control seedlings, this accounted for 84 % of the N stored in stems and roots. For fall fertilized seedlings, however, the proportion of N stored in stems and roots translocated from needles accounted for only 41–61 % of the total because of absorption of fall fertilizer that was translocated directly to stems and roots. Six weeks after fall fertilization, the distribution pattern of N concentration and content in seedlings was found in this order: stems > fine roots > coarse roots > needles. Our results suggest that providing deciduous conifer seedlings N during hardening, in this case Olga Bay larch, is a way to promote nutrient loading during nursery production.