欧美108杨速生丰产林水氮耦合效应研究

发布时间：2018-03-09 12:26

  本文选题：欧美108杨　切入点：速生丰产林　出处：《北京林业大学》2016年博士论文　论文类型：学位论文

【摘要】：当前,我国木材对外依存度已超过50%,同时随着我国对天然林实施全面保护措施及国际木材贸易保护意识的逐渐提升,我国的木材安全问题日益严峻,故大力营造和发展速生丰产用材林来缓解木材短缺势在必行。我国杨树人工林面积位居世界第,占全国乔木人工林的18.1%,大力营造和发展和杨树速生丰产林是解决木材安全问题的重要途径,但我国杨树人工林平均生产力目前在15 m3.hm-2.yr-1以下远低于世界平均水平。国内外诸多学者提出合理高效的集约水肥经营管理措施是有效提高速生丰产林生产力的重要手段,同时还可达到节水、减氮和增产的目的。将灌溉和施肥措施结合起来可以使水和肥两者的供应具有同步性,从而有效提高水肥利用效率。因此,在我国杨树速生丰产林的大力发展和经营过程中,选择恰当合理的水肥投入方式、投放时期、合理配比、最佳用量等关键技术可对林木速生、节水节肥以及减少环境污染具有重要意义。本文以欧美108杨(Populus×euramericana cv.'Guariento')为研究对象,将地表滴灌和随水施肥技术结合起来共同应用到杨树速生丰产林的水肥管理中,旨在从树木生理生态特性、细根生长与分布、林木生长、林地生产力和碳储量等方面进行欧美108杨水氮耦合效应研究,探明水氮耦合策略促进林木生长的作用机理,并综合提出其高效的最佳滴灌和施肥技术组合。这将有助于提升杨树速生丰产林的水分和养分管理水平,并为我国杨树速生丰产林的水肥管理提供一定的技术借鉴和理论指导,主要研究结果和结论如下：(1)水氮耦合措施有效改善了欧美108杨林地土壤水分和养分状况。在林木生长最快的4-7月土壤水势(ψs)波动幅度较大,7-8因降雨集中各处理的ψs值波动幅度相对较小,随后在9-11月份ψs值又开始出现新的波动,故生长季内需要进适时灌溉才能使各处理ψs保持其设定的阈值之上。在实施水氮耦合措施的3个生长季内,-25、-50和-75 kPa三个灌溉水平下的林地平均ψs保持在-13.79- -14.19 kPa、-21.15--25.83 kPa、-29.88- -37.00 kPa范围内；林地20 cm深处的土壤含水率在3个滴灌水平下分别比CK提高61-69%、50-56%和27-55%。水氮耦合措施对林地土壤养分的影响显著,如采取措施第一年,各耦合处理下0-20 cm土层有机质和全氮含量分别比CK显著高出1-81和3-59%,到第二年分别比CK高出29-134和31-81%。最优耦合处理D3F3下的各养分含量最高,如措施第一年3个土层的有机质含量分别比CK高出82、25和4%,第二年分别比CK高出107、106和75%。综上,水氮耦合措施可有效改善欧美108杨林地土壤水养资源,为促进其林木生长提供了良好的立地条件。(2)欧美108杨细根主要分布在0-20 cm土层,耦合措施实施第一年,各水氮耦合处理中D3F3处理促进细根生长的效果最显著,其3个土层细根生物量较CK分别提高了316、386和442%,根长密度较CK分别提高345、176和132%。耦合措施实施第二年,各土层细根生物量密度、根长密度和平均直径均表现为：高水高肥(D3F3)和中水高肥(D2F3)2个处理间差异不显著,但均显著高于其它处理,其中D3F3处理6个土层生物量密度是CK的3.12-47.74倍；细根表面积是CK的4.36-30.57倍。当灌溉量一定时,增加施肥量可显著促进欧美108杨细根的生长,但当施肥量一定时增加灌溉量对促进细根生长的效果不显著,即趋肥性强于向水性。欧美108杨细根生长对水氮耦合措施下所改善的林地土壤水养资源表现出高度可塑性,以此提高了林木吸收水养的能力,成为耦合措施促进其林木生长的重要机理之一。(3)水氮耦合措施会显著提高其叶片LAI、Pn、WUE和树干Vsf,且其影响随着措施实施年份越久其影响越显著。在3个生长季内,具有最大年均LAI的处理为D3F3,其年均LAI分别比CK显著高出21、44和58%。叶片Pn和WUE均是水氮耦合处理显著大于CK,在5a和6a生时,Pn分别比CK提高了23-63%和26-95%,WUE分别比CK提高30-110%和18-82%。树干Vsf与Rs、Ta、SWC和VPD呈极显著的正相关关系,与RH呈极显著负相关性,各水氮耦合处理的树干Vsf均显著大于CK,如在7月份,5a和6a生欧美108杨树干Vsf日均值在9个耦合处理下分别比CK提高27-70%和13-69%。水氮耦合措施中的灌溉水平对欧美108杨各生理生态因子的影响相比施肥水平和水氮交互作用更为显著,且对施肥效果的响应具有一定的滞后性。(4)地表滴灌和随水施肥(SDIF)措施可显著增加欧美108杨速生丰产林生物量和碳储量。5-7a生时林分生物量在SDIF处理下分别为11.49、27.68和38.70 t·hm"2,相比CK的7.54、15.77和24.88 t·hm-2分别提高了52、75和60%。欧美108杨林.木各器官有机碳含量在SDIF和CK处理之间无显著差异,各器官有机碳含量平均在46.28-58.30%范围内。5-7 a生时林分碳储量在SDIF处理下分别为6.20、15.18和21.72 t-hm-2,相比CK处理的4.05、8.63和13.46 t-hm-2分别增加了53、76和61%。5和6a生欧美108杨林地0-60 cm土层碳储量分别达到50.87和61.32 t·hm-2,相比CK的43.08和47.92 t·hm-2分别显著提高18和28%。(5)水氮耦合措施可显著促进欧美108杨林木生长并提高林地生产力。在措施实施第一年,最优耦合处理D3F3使5a生欧美108杨DBH、H和V年生长量分别达到4.9cm、3.0m和11.54 m3·hm-2·a-1,相比CK的4.0cm、1.9m和8.01 m3·hm-2·a-1分别提高23、58和44%；措施实施第二和三年,最优耦合处理D2F3使6和7a生欧美108杨DBH、H和V的年生长量分别达到5.6和3.1cm、4.2和2.3 m、27.85和25.96m3·hm-2·a-1,较CK的4.2和2.5 cm、3.3和1.6 m、20.48和16.58 m3.hm-2·a-1分别提高33和24%、27和44%、36和57%。水氮耦合措施下5-7 a生欧美108杨速生丰产林最高经济收益可达5522.37-39619.07元/公顷,比CK的4311-32429元/公顷增加22-28%。水氮耦合措施中各因子对欧美108杨林木生长和生产力的影响大小依次为：施氮水平水氮交互灌溉水平。此外,欧美108杨在水氮耦合措施下林木IDBH、IH和Iv与各因子的偏相关系数大小顺序依次为：土壤有机质(OM)土壤含水率(SWC)土壤全氮(N)叶面积指数(LAI)细根生物量(FRB)净光合速率(Pn)水分利用效率(WUE)树干液流速率(Vsf),最大偏相关系数为0.887,最小为0.315。综上,在对与本试验地环境相似地区的欧美108杨人工林进行水肥管理时：①地表滴灌的灌溉起始阂值应该在生长季内控制滴头正下方20 cm处的土壤水势在-25-50kPa范围；②生长季内的早春旱季(4-5月)灌溉次数和量较大,6-10月结合降雨情况,可降低灌溉次数和量；③欧美108杨栽植后的1-4年内采取滴灌施N措施可显著促进林地生产力,适宜施N量为450-600g/株/年,在生长季内4-8月份进行少量多次施肥,首次施肥应在展叶前进行；④根据根系分布规律和节水节肥的集约经营理念出发,滴灌垂直湿润区应维持在0-50 cm深度,水平湿润区应达到距离滴头50 cm处。
[Abstract]:At present, China's dependence on foreign timber has more than 50%, at the same time, along with the gradual upgrading of China's implementation of the comprehensive protection measures and the international timber trade protection consciousness of the natural forest, timber safety problem in China is becoming more and more serious, so vigorously to create and development of plantation to alleviate the shortage of wood of poplar plantation area I is imperative. Country in the world, accounting for 18.1% of tree plantations, vigorously to create and develop and poplar forest wood is an important way to solve security problems, but China's current poplar Lin Pingjun productivity below 15 m3.hm-2.yr-1 far lower than the world average level. Many scholars put forward the intensive fertilizer management measures is reasonable and efficient effectively improve the fast-growing and high-yield forest productivity is an important means, but also can achieve the water saving, reducing nitrogen and yield. The irrigation and fertilization measures can be combined with The water and fertilizer supply is synchronous, so as to effectively improve water use efficiency. Therefore, in our country to develop Yang Shusu growing forest and operation process, choose appropriate water and fertilizer inputs, delivery period, reasonable ratio, the optimum amount of the key technology of fast-growing trees, saving water and fertilizer and reduce the pollution of the environment is of great significance. This paper in Europe and the United States 108 Yang (Populus * euramericana cv.'Guariento') as the research object, the surface drip irrigation and fertigation technology together applied to poplar forest management of water and fertilizer, to trees from the physiological and ecological characteristics and fine root growth and distribution, forest productivity and forest growth. Carbon storage and other aspects of research and the 108 Yang coupling effect of water and nitrogen, explore the strategy of water and nitrogen coupling mechanism of promoting tree growth, and put forward the best and efficient application of drip irrigation Fertilizer technology portfolio. This will help to improve the moisture of poplar forest and nutrient management, provide certain technical reference and theoretical guidance for China's management of water and fertilizer and poplar forest, the main research results and conclusions are as follows: (1) measures of water and nitrogen coupling effectively improve the Euramerican poplar 108 the soil moisture and nutrient status in the forest. The fastest growth of 4-7 monthly soil water potential (PSI s) greater volatility, 7-8 due to the concentrated rainfall s value fluctuation of PSI is relatively small, then in the 9-11 month psi s value also began a new wave, so the growing season needs to make timely irrigation the PSI s maintains its threshold. In the implementation of measures of water and nitrogen coupling of the 3 growth of Tine, -25, s and -75 -50 forest average psi kPa three irrigation levels remained at -13.79--14.19 kPa, -21.15--25.83 kPa, -29.88--37.00 kPa within the scope of the forest; The content of soil water to a depth of 20 cm at the rate of 3 a level higher than CK under drip irrigation were 61-69%, 50-56% and 27-55%. effects of water and nitrogen coupling measures on soil nutrient significantly, such as measures to the first year, the coupling treatment 0-20 cm soil organic matter and total nitrogen content were significantly higher than the CK 1-81 and 3-59%, to second years were 29-134 higher than that of CK and 31-81%. optimal coupling treatment under D3F3 nutrient content was the highest in the first year, measures such as organic matter content of the 3 soil layers were higher than that of CK and 82,25 in 4%, second years were 107106 higher than that of CK and 75%. in water and nitrogen coupling measures can effectively improve the soil and water resources 108 poplar, in order to promote the growth of trees provides a good site conditions. (2) and 108 Yang Xigen are mainly distributed in 0-20 cm soil layer, coupling measures to implement the first year, the coupling of water and nitrogen treatment D3F3 could promote root growth effect Obviously, the 3 fine root biomass compared with CK were increased by 316386 and 442%, the root length density were more than that of CK 345176 and 132%. coupling measures for the implementation of second years, the density of fine root biomass, root length density and average diameter were: high water fertilizer (D3F3) and D2F3 (high water fertilizer) differences between the 2 treatments was not significant, but significantly higher than other treatments, the treatment of D3F3 6 soil biomass density is 3.12-47.74 times of CK; fine root surface area is 4.36-30.57 times of CK. When the irrigation amount, increasing the amount of fertilizer can significantly promote the Euramerican poplar 108 fine root growth, but when a certain amount of fertilizer when the increase of irrigation amount to promote root growth effect is not significant, the trend was stronger than that of water fertilizer to the soil water resources. Forest Populus euramericana 108 improvement measures for fine root growth under water and nitrogen coupling showed a high plasticity, in order to improve the absorption of water in the forest Ability to become one of the important measures to promote the coupling mechanism of tree growth. (3) measures of water and nitrogen coupling will significantly increase the leaf LAI, Pn, WUE and Vsf trunk, and the effect with the measures for the implementation of a year longer. Its influence is more significant in 3 growth Tine, processing with the largest annual LAI D3F3. The average LAI had significantly higher respectively than the CK 21,44 and 58%. Pn in leaves and WUE are water and nitrogen treatment was significantly higher than that of CK, 5A and 6A in Pn, respectively than CK increased 23-63% and 26-95%, WUE and 18-82%. respectively higher than CK 30-110% Vsf and Rs Ta, the trunk, and positively correlated significantly the SWC and VPD, showed a significant negative correlation with RH, the coupling of water and nitrogen treatment trunk Vsf were significantly higher than that of CK, such as 5A and 6A in July, 108 American poplar stem daily average Vsf in 9 coupled processing respectively higher than CK 27-70% and 13-69%. of water and nitrogen coupling measures in irrigation water level for 108 Yang Ge Effect of physiological and ecological factors than the fertilization level and water nitrogen interaction effect is more significant, and the response to fertilization effect has a certain lag. (4) surface drip irrigation and fertigation (SDIF) measures can significantly increase the yield in Europe and 108 poplar forest biomass and carbon storage of forest biomass in.5-7a at SDIF under the treatment of 11.49,27.68 and 38.70 respectively t HM 2, compared to CK 7.54,15.77 and 24.88 t hm-2 respectively increased 52,75 and 60%. and Yang Lin 108. No significant differences in wood organs between SDIF and organic carbon content in different organs of CK treatment, the average organic carbon content in the range of 46.28-58.30%.5-7 a when the carbon the reserves under SDIF treatment were 6.20,15.18 and 21.72 t-hm-2, compared to CK treated 4.05,8.63 and 13.46 t-hm-2 were increased by 53,76 and 61%.5 and 6a and 108 poplar 0-60 cm soil carbon reserves reached 50.87 and 61.32 T / hm-2, phase More than 43.08 of CK and 47.92 t hm-2 respectively increased 18 and 28%. (5) measures of water and nitrogen coupling can significantly promote the European Yang Linmu 108 growth and improve forest productivity. In the first year of the implementation of measures, the optimal coupling treatment D3F3 5A and Yang DBH H and V 108, annual growth reached 4.9cm and 3.0m respectively. 11.54 m3 - hm-2 - A-1, compared to CK 4.0cm, 1.9m m3 and 8.01 hm-2 A-1 respectively increased 23,58 and 44%; measures for the implementation of second and third years, the optimal coupling treatment D2F3 6 and 7a 108 and Yang DBH, H and V annual growth reached 5.6 and 3.1cm, 4.2 and 2.3 m, 27.85 25.96m3 and hm-2 A-1, a 4.2 CK and 2.5 cm, 3.3 m and 1.6, 20.48 and 16.58 m3.hm-2 A-1 respectively increased by 33 and 24%, 27 and 44%, 36 and 57%. 5-7 measures of water and nitrogen coupling a Europe 108 poplars high-yield forest maximum economic yield of up to 5522.37-39619.07 yuan / ha, 4311-32429 CK increased 22-28%. yuan / ha Each factor measures of water and nitrogen coupling in order for the influence on the growth and productivity of the 108 American Yang Linmu size: nitrogen levels of water and nitrogen interaction irrigation level. In addition, 108 poplar trees in Europe and the measures of water and nitrogen coupling under IDBH, the sequence of partial correlation coefficients of IH and Iv and all the factors are: soil organic matter (OM) soil moisture (SWC) soil total nitrogen (N) leaf area index (LAI) of fine root biomass (FRB) net photosynthetic rate (Pn) and water use efficiency (WUE) sap flow rate (Vsf), the maximum partial correlation coefficient was 0.887, the minimum is 0.315. so on and the experimental environment similar regions of Europe and 108 poplar plantation irrigation water and fertilizer management: the initial threshold value should control surface drip irrigation emitters in the growing season just below the 20 cm soil water potential in the range of -25-50kPa; the growing season in the spring dry season (4-5 months) and the number of times a large amount of irrigation, combined with 6-10 months The rain, can reduce the number and volume of irrigation; the European 108 poplar 1-4 years after taking fertigation N measures can significantly promote the productivity of forest land, suitable amount of N for strain 450-600g/ / year, for a small number of fertilization in the growing season for the first time in 4-8 months, fertilization should be in before the exhibition leaves according to the root; distribution and saving water and fertilizer intensive irrigation management idea, vertical wetted area should maintain at 0-50 cm depth, horizontal wetted area should reach 50 cm away from the emitter.

【学位授予单位】：北京林业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S792.11
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本文编号：1588544