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1.
不同起源沙地樟子松林结构与生长比较研究   总被引:2,自引:0,他引:2  
樟子松已成为三北沙区防护林主要乔木造林树种,但是,最早于20世纪50年代在科尔沁沙地引种的沙地樟子松却出现了生长衰退、枯梢直至死亡的现象,而天然状态的樟子松在该阶段却正处于旺盛生长期。为了比较沙地人工樟子松林与天然林的林分结构、生长特点及所处立地的生态因子的异同,对辽宁省彰武县章古台(最早引种沙地樟子松区)和内蒙古自治区红花尔基(天然樟子松分布区)的樟子松林进行了综合调查。结果表明,Weibull分布函数可较好地模拟人工林树木直径分布,正态分布函数可用于模拟天然林树木直径分布。基于树干解析的树木生长模型(Chapman-Richards)分析,人工林胸径、树高与材积的相对生长率与平均生长率的最大值比天然林分别提早11、22年,6、18年和35、59年。人工林材积的生长加速度高峰值出现在14年,而天然林则出现在33年;人工林的数量成熟龄为43年,天然林为102年;因此,可以推断天然林的寿命比人工林要长近60年。这一结果可以归纳为以下综合作用:1)两种起源地生态因子的巨大的差异,主要包括:人工林区的纬度、平均气温、降水量、蒸发量、海拨高度等较天然林区高;2)人工林的林分密度较天然林大;3)人工林区的干扰强度较天然林强。图4表6参23。  相似文献   

2.
In order to examine the causes of degradation of Pinus sylvestris var. mongolica plantations on sandy land, the foliar concentrations of N, P, K and C were analyzed and compared between the field grown P. sylvestris var. mongolica trees from two provenances (natural forests and plantations). The results indicated that natural tree needles had lower N, P and C concentrations, and higher K concentrations than those of plantation tree needles. For plantation tree needles, ratios of N: P, P. K and N: K increased with tree age before 45 years old; but they were not clear for the natural tree needles. Compared with the conclusions reported on Pinus spp., we found that the foliar N and P concentrations were in the optimal range for both natural and plantation tree needles. This result suggested that N or P might not be the absolute limit factors in plant nutrient for P sylvestris var. mongolica on sandy land. However, foliar K concentrations in both natural and plantation tree needles were much lower than those reported on Pinus spp. (〉4.80 g kg-1).The N: P ratio of natural needles was in the adequate ranges, but N: P ratio of plantation needles was out of the adequate ranges. These results indicated that there was a better balanced nutrition status in the natural forest than in the plantations. If only considering the foliar nutrient concentrations of P sylvestris var. mongolica from different provenances, it might be concluded that the degradation phenomenon of P. sylvestris var. mongolica plantations was not induced by nutrition deficiency of absolute nutrients of N and P, but might be induced by other mineral nutrients or by the effectiveness of N and P nutrients. The unbalanced nutrition status and relatively quick decomposition of needles in the plantations might also contribute to the degradation.  相似文献   

3.
Natural regeneration in Mongolian pine, Pinus sylvesttis var. mongolica, forest at Honghuaerji of China (the original of the natural Mongolian pine, forest on sandy land) was studied in 2004. The total mean values of regeneration indexes were higher in mature stands (more than 80% individual stems were older than 50 years), the maximum of regeneration index reached 29 seedlings, m^ 2, with lowest values in the younger stand, e.g., in 32-year old and 43-year old stands. The stand age was an important factor determining the natural regeneration, which was the best in the older stands in this investigation (e.g. about 80-year old). The regeneration index seemed not to be closely in relation to canopy openness although Mongolian pine is a photophilic tree species. In each type of gaps, natural regeneration was very well. Regeneration indexes were satisfactory at the south and east edges in the circle gaps; and at the east edge of the narrow-square gaps. Results indicated that Mongolian pine, seedlings could endure shading understory, but it would not enter the canopy layer without gap or large disturbance, e.g., fire, wind/snow damage or clear cutting etc. These results may provide potentially references to the management and afforestation of Mongolian pine, plantations on sandy land in arid and semi-arid areas. Researches such as the comprehensive comparisons on regeneration, structure and ecological conditions and so on between natural Mongolian pine, forests and plantations should be conducted in the future.  相似文献   

4.
为了诊断沙地樟子松人工林的衰退原因,我们比较分析了沙地樟子松天然林和人工林中的叶片养分含量。结果表明,天然林中的樟子松叶片内氮、磷含量均比人工林中低,而钾含量比人工林高。樟子松人工林叶片中 N:P, P: K 和N: K在45年前随年龄增加而增加,从植物养分含量的角度来看,这一结果表明氮或磷可能不是沙地樟子松生长的绝对限制因子。然而,天然林和人工林叶片中的钾含量比以前报道过的松属植物中的含量都要低。天然林叶片中的N: P比值在正常的范围内,但人工林的则在该范围以外。这些结果表明天然林具有比人工林更好的养分平衡状况。如果只从樟子松的生长地来考虑,我们可以认为樟子松人工林的衰退现象可能是因其它的矿物元素或者氮和磷的有效性,而不是氮和磷的绝对含量不足造成的。养分的不平衡状况和人工林内针叶快速分解可能也是衰退的重要因素。图3表3参42。  相似文献   

5.
The biomass and net primary production of Mongolian scotch pine (Pinus sylvestris L. var.mongolica) plantations of west Kerqin sandy land were measured. According to average standard trees, the biomass, net primary production and their distributions of trunk, bark, branch, leaf and root of 16-year-old stand were analyzed. The regressive equation for the estimation of each organ biomass was established through dimensional analysis. Preferable equation with higher precision was selected. The study results showed that the total biomass of the forest community was 62.023 t/hm2 and net primary production was 5.045 t/(hm2·a), which indicates that the community of plantation possesses high bio-productivity. (Responsible Editor: Chai Ruihai)  相似文献   

6.
Effects of drought stresses induced by polyethylene glycol (PEG) (0.0%, 10%, 15%, 20%, 25%, and 30%, with four replicates) on germination of Mongolian pine (Pinus sylvestris var. mongolica) seeds produced in plantations (southern Keerqin sandy land) and natural forests (Hulunbeier sandy plain) were observed. The results indicated that the seeds from both provenances did not germinate when PEG concentration was more than 25%. The time of initial germination and that of its completion of stressed seeds from both provenances were delayed when compared with the unstressed seeds. The germination capacity and germination rate of natural seeds were significantly higher than those of plantation seeds for all treatment levels (P < 0.05). The mean growth rates of radicle and hypocotyl from natural seeds were significantly higher than those from plantation seeds at all treatment levels below 20% PEG treatment (P < 0.05). The ratios of radicle to hypocotyl of 20% PEG treatment were significant higher than those of the corresponding controls for both provenances (P < 0.05). These results suggested that Mongolian pine seeds/seedlings had stronger resistance to PEG drought stresses; 10% PGE stress did not significantly influence germination. Natural seeds exhibited more resistance to PEG stress than plantation seeds. It was concluded that drought stress on seed germination might be one cause of obstructed natural regeneration of Mongolian pine plantations on sandy land. It is recommended that natural seeds be used for afforestation, and light drought stress (e.g., 10% PEG stress) may be useful in improving seed germination and the growth of radicles and hypocotyls.  相似文献   

7.
樟子松是沙地主要针叶造林树种,沙地樟子松林天然分布于内蒙古自治区呼伦贝尔市红花尔基;红花尔基地区的气候特点为高纬度、低海拔、寒冷半湿润、短无霜期。沙地樟子松于20 世纪50 年代在科尔沁沙地引种成功,但一直不能天然更新,并于 20 世纪 90 年代初出现了生长衰退、枯梢直至死亡的现象,而天然沙地樟子松林无论在更新还是生长上却一直处于健康状态。为了认识天然沙地樟子松林天然林的更新特征,于 2004 年 7-8 月对红花尔基天然沙地樟子松林的20 块样地、3 种林窗(2 圆形、5 窄长方形、3 宽长方形)樟子松天然更新指数进行了调查。结果表明,林龄大的林分(大于 50 年)总平均更新指数高于林龄小的林分(小于 50 年),最大更新指数达29株m-2。更新的苗龄绝大多数小于10年生。回归分析表明,林龄是决定天然更新的主要因子;虽然樟子松是阳性树种,但林冠的郁闭度似乎对天然更新没有直接影响。林窗更新调查结果表明,林窗内更新指数都较高;对于圆形林窗更新高峰出现在林窗南缘和东缘,而对于窄长方形林窗,更新高峰则出现于东缘;而且更新苗龄相对较大(最大达 38 年)。上述结果表明樟子松更新苗具有一定的耐阴性,但如果没有较大林窗或较大的其它干扰,如火、风雪害或皆伐等,更新苗木将很难进行入主林冠层。  相似文献   

8.
This paper summarizes the result from the provenance test of eight years oldPinus sylvestris var.mongolica in Liangshui Natural Reserve comprehensively. The main contents include:(l) the geographic variation of the growth characters ofPinus sylvestris var. mongolica, tends to negative change gradually at latitude and has obvious climatic nature, (2) no significant difference exists in the morphological adaptability and resistant characteristics and so on; (3)on the basis of the geographic variation study on the growth characteristics, the provenances ofPinus sylvestris var.mongolica were classified into two geographic populations and two subpopulations as follows: the northern population of the Daxing’an Mountain (I) and the southern population of the Daxing’an Mountain as well as the Xiaoxing’an Mountain (II), which includes Honghuarji subpopulation (II -1) and Kalunshan subpopulation (II-2). (4) the height growth rhythm was analyzed according to the divided population and subpopulation; (5) the best provenance was selected for the Liangshui Natural Reserve and its neighborhood according to the results from SSR test of the growth characteristics (the breast height diameter and height of eight year old trees), the possibility of the early provenance selection was also verified by the method of order correlation analysis on the height growth of three, five, seven and eight years old provenances.  相似文献   

9.
The spatial distribution pattern of needle bright disease was mathematically studied. The results showed that it is tally with negative binomial distribution. The infected area and damaged amount can be forecasted with this spatial distribution pattern. Through the study on probability distribution of spatial points for single tree, the method and equations for calculation of the disease index of whole forest belt were determined. (Responsible Editor: Chai Ruihai)  相似文献   

10.
In order to find out the best foliar diagnostic index of phosphorus (P) nutrition in Mongolian pine (Pinus sylvestris var. mongolica) in the southeastern Keerqin Sandy Lands, the concentrations of total nitrogen (N), inorganic P, organic P and total P in needles of different ages and soil available P were examined. The results show that in the study area, soil available P was rather low (0.12–0.63 mg/kg) and was significantly correlated with inorganic P (cPi) and total P (cPt) concentrations in current year needles of Mongolian pine. The significant correlation between soil available P and needle cPt derived from the significant correlation between cPi and cPt. Compared with cPt, cPi did reflect the level of soil P supply more accurately and more directly. __________ Translated from Chinese Journal of Applied Ecology, 2008, 19(3): 494–498 [译自: 应用生态学报]  相似文献   

11.
lntroductionMongoIianscotchpine(PinussyvesmeL.var,mon-gohbe)isafondamentaItreespeciesincoIdtemper-atezone,mainlydistributedinHeiIongjiangProvinceandDaxing'anMOuntainforestregionoflnnerMon-goIiaAutonomousRegion.Withhighendurancetocold,droughtandpoorsoil,thistreespecieshasthecharacteristicsoff8stgroWth,shortfinaIcuttingageandgoodqualitytimber,atc-.IthasbeenproventhatMongoIianscOtchpineisoneofthemostsuccessfuIIyintroducedtreespeciesinsemi-aridregionafterbeingintroducedinto13provincesandau…  相似文献   

12.
沙地樟子松人工林合理经营密度的研究   总被引:4,自引:0,他引:4  
通过调查不同密度的沙地樟子松人工林胸径、树高、蓄积、干形等生长指标和松枯梢病的发病情况等健康指标,分析了密度对樟子松人工林生长与健康的影响。综合分析得出:亚湿润干旱区樟子松人工林的造林密度可以控制在1 250~2 500株·hm-2;当樟子松人工林林龄达到21 a时保留密度1 000株·hm-2左右;当林龄31 a时,密度控制为500株·hm-2左右。  相似文献   

13.
该文以林龄为32 a的樟子松林作为研究对象,研究了沙地樟子松人工林林内K、P、Mg、Zn、Cu、Fe、Mn等矿质元素2010-2011年通过降雨输入、地表径流输出以及积累、留存、淋溶、归还、吸收等循环过程。结果表明:沙地樟子松林林分矿质元素的收入大于支出,呈盈余状态。但林分的生产力却比较低,生物生产量仅为2.604 t·hm-2·a-1,原因可能是樟子松林对矿质元素的利用率较低。同时林分的归还量少,林分矿质元素循环效率低。建议采取人工措施调控樟子松林,建立良性循环的生态系统。  相似文献   

14.
Fixed quadrates were established in different stands. In continued six years, the occurring period, occurring amounts and the relation between epidemic disease and environmental factors were investigated according to spraying laws of spores and accounting measures of disease ranking. The occuring peak period of the disease was from the last ten days of May to the second ten days of June. The epidemic period was from the last ten days of June to the second ten days of July and the initial decease period was from the last ten days of July to the beginning of September. The change of the disease depended on air temperature, relative humidity and precipitation. A multiple linear regression model was established using computer, which can predict the disease index(Y) of 10 days later, with more than 95% reliability (Responsible Editor: Chai Ruihai)  相似文献   

15.
沙地樟子松天然更新与降水因子的灰色关联度分析   总被引:2,自引:0,他引:2  
沙地樟子松人工固沙林的天然更新在大部分引种地不能很好地进行,其天然更新存在着某些障碍因子。通过对辽宁省昌图县傅家林场樟子松天然更新情况的调查,采用灰色关联度分析的方法,对更新与降水因子的关系进行了分析。结果表明,更新产生的当年12月和翌年1,2月的降水量,即冬季降雪情况与天然更新关联最大。说明了冬季降雪是影响樟子松天然更新的一个关键因子。  相似文献   

16.
利用盆栽试验,研究施入不同比例的泥炭、风化煤对风沙土的改良作用及其促进樟子松幼苗生长的效果,并初步分析了两种有机物料的作用机理。试验结果表明,泥炭和风化煤都显著地改良了风沙土的理化性质,随着施入量的增加,两者对风沙土的影响都表现出土壤pH值下降、持水量增加、养分含量提高,且泥炭的效果普遍比风化煤的效果要好;两者均促进了樟子松幼苗生长。不同含量的泥炭对促进樟子松幼苗生长(苗高、地径、根长、生物量)的效果表现为8%>10%>5%>2%>0。不同含量的风化煤对高生长的影响依次是5%>8%>10%>2%>0,对地径生长的影响依次为5%>8%>2%>10%>0,对生物量的影响依次为5%>2%>8%>10%>0。总的来看,泥炭的效果比风化煤好。结合樟子松在沙地中的生长特性,推断泥炭和风化煤中含有微量抑制樟子松生长的物质,并提出8%的泥炭与风沙土之比是促进沙地樟子松幼苗生长的最佳配比。  相似文献   

17.
沙地樟子松生长规律的研究   总被引:7,自引:0,他引:7  
通过对内蒙古红花尔基林业局经营的沙地天然樟子松的生长特别和分布规律的研究,结果表明:沙地樟子松生长在不同光照条件和不同密度的环境下,林木的高生长和胸径生长存在很大的差异,樟子松在疏林(0.3~0.5)时,高生长快,胸径生长正常,材积生长数高。  相似文献   

18.
Changbai pine (Pinus sylvestris var.Sylvestriformis) is an endemic and important tree species in Changbai Mountain. There were only 63 plant species in Changbai pine plantation, where hemicryptophyte was dominant(39.68%). Simpson diversity index was 0.87, Shannon-Wiener diversity index was 2.96, and evenness index was 0.82. Community structure were divided into three layers: tree layer, shrub layer and herb layer. The total biomass and net production were 111.982 t/hm2 and 8942.80 kg/(hm2 a) respectively. The total biomass for tree, shrub and herb layers were 106.150, 2.230, 2.264 t/hm2, accounting for 94.79%, 1.99%, and 2.02%, respectively, and net production for those were 7465, 223, and 1182 kg/(hm2 a), accounting for 83.47%, 2.49%, and 13.22% of the total respectively. The nutrient content in various organs is in the order of needle> branch> root> bark> trunk, For the assimilated organ, the nutrient content is in the order of N> K> Ca> P> Mg, and that in absorption organ is in the order of Ca> N> K> P> Mg. For the whole plantation ecosystem, nutrient content is in the order of soil> litter> herb layer> shrub layer> tree layer. Nutrient storage and its accumulation rate in tree layer take up 88.79% and 76.43% of the total, respectively. The project is funded by the Opened Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences Responsible Editor: Chai Ruihai  相似文献   

19.
章古台沙地樟子松人工林土壤水分动态研究   总被引:11,自引:1,他引:11  
对章古台地区沙地樟子松人工林和流动沙地土壤水分动态进行了定位研究,结果表明,在整个生长季节内,降雨、蒸散、地形及土壤质地等因素对沙地土壤水分变化影响显著。0-100cm土层土壤贮水量以沙丘下部林地为最高,流动沙地次之,丘顶林地最低。表层0-5cm土壤含水量受降雨影响变幅较大,林地高于流动沙地;樟子松主要根栖层25-50cm土壤含水量低于流动沙地。5、6、9月为失墒期,7—8月为蓄墒期,其中以6月份土壤贮水量为最低。  相似文献   

20.
Water potential (ϕ w) and net photosynthetic rate (Pn) ofLarix olgensis andPinus. sylvestris var.mongolica decreased with the decrease of soil water content. ϕ w and Pn ofL. olgensis changed hardly during the first 9 days after stopping watering, then decreased sharply at the 10th day Pn ofP. sylvestris varmongolica decreased slightly during the first 8 days, then decreased sharply at the 9th day. Their respiration rate, chlorophyll content and their a/b ratio changed hardly. The following 3 conclusions were obtained and discussed exhaustively. (1) ϕ w can be used to direct watering as a sensitive index of judging whetherL. olgensis andP. sylvestris var.mongolica lacking water. (2) The decrease of Pn ofL. olgensis andP. sylvestris var.mongolica when drought had nothing to do with chlorophyll. (3)P. sylvestris var.mongolica had morphological drought resistance, while Lolgensis had physiological drought resistance, and their drought resistance was discussed comparatively first time.  相似文献   

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