中国三明地区天然林林窗大小对环境异质性和格氏栲更新的影响

发布时间：2018-06-18 07:24

  本文选题：林窗大 + 微环境异质性　； 参考：《福建农林大学》2017年博士论文

【摘要】：林窗是由老树死亡、昆虫、某些疾病或雷电袭击、风或风暴吹倒、或其他倒下的树木击倒的区域。林窗的出现提高了森林动态。因此,林窗对维持森林生态系统很重要。当林冠层开阔形成林窗时,影响小气候、光照强度、土壤温度、气温和土壤水分的改变。中国福建三明的格氏栲天然林是以过熟的格氏栲(平均年龄超过100年)、米槠、马尾松与木荷为优势的亚热带常绿阔叶林,也是面积最大纯度最高的格氏栲天然林。许多研究人员都在研究这个物种。关于格氏栲天然林林窗的研究表明不同大小林窗和林窗内位置具有不同的土壤-空气温度、相对湿度和土壤含水量。那些环境条件也受季节影响。不同微地形的环境条件下可能影响格氏栲种子萌发和幼苗定居。之前的研究关注于林窗微气候研究。目前,由于格氏栲幼苗和幼树减少,使格氏栲种群不断下降,种群年龄结构不可持续,主要原因是种子萌发和幼苗定居不足和人为干扰的影响。承前所述,林窗能够影响物种更新,但目前发现多数研究这关注于林窗微环境研究。林窗环境的空间异质性和林窗大小影响微环境仍未知,关于幼苗更新机制和其对微环境的响应也未知。为此,探索了林窗影响微环境及环境因子影响叶片性状和林窗内格氏栲幼苗对微环境的响应。研究目的:1)调查林窗对白天时间的微环境动态的影响;2)揭示林窗大小对土壤化学-物理性质的影响;3)调查光照强度对微环境和叶片性状的影响;4)调查更新层叶片性状对林窗微环境的响应;5)调查林窗大小和林窗内不同位置对格氏栲更新的影响。结果表明:通过鱼眼镜头在每个林窗中心拍两张照片,采用半球面影像法计算林窗面积。测量了 9个林窗,其中,最大的林窗面积为216.72m2,最小的林窗面积为30.28 m2。根据林窗面积大小,将9个林窗分为3类不同大小的林窗(小(30-50 m2)、中(50-100 m2)、大林窗(150 m2)),小林窗由树枝折断产生,大中型林窗由树倒产生,同时,设置15 m×15 m的非林窗为对照。在整个林窗和非林窗内设置3 m×3 m的网格作为取样点。在整个林窗内从早晨8点到下午6点,每2h记录一次微环境因子变化,微环境因子包括土壤表层温度(ST0)、土壤深度为5cm的温度(ST5)、土壤深度为10cm的温度(ST10)、空气温湿度(AT)、光照强度(LI)和相对湿度(RH)等,数据从2014年6月15-25日和2015年1月5-15日。采用地统计分析法,阐述了 9个林窗和非林窗土壤物理-化学性质和土壤酶活性的空间模型,调查林窗大小和微环境对林窗内叶片性状的影响。在林窗和非林窗内的5个方向设置5 m×5 m样方收集叶片样本。于冬季和夏季收集更新层叶片(2 cmDBH,高度2-5 m.)测定叶片性状。选择的叶片性状包括:叶面积(LA)、叶干物重量(LDM)、比叶面积(SLA)、叶绿素a(Chla)、叶绿素b(Chlb)、总叶绿素含量(TChl)、类胡萝卜素(CAR)、可溶性糖含量、淀粉含量、氮含量(N)、碳含量(C)、磷含量(P)、钾含量(K)与叶片酶活性。对物种管理和保护,探讨了林窗是否有可能促进格氏栲幼苗更新,并调查了林窗内幼苗更新的最佳位置。在夏季林窗(中心、南方、东方、北方和西方)的五个方向调查格氏栲四个阶段(树木,树苗,灌木和幼苗)的基径、高度和数量。研究结果如下:微环境随时间而变化。在每个林窗内,从早晨10点到下午2点,林窗中心LI最强。除大林窗的北方向外,其他林窗均表现为北和西方向高于南和东方向。非林窗内,LI与ST呈显著正相关关系。不像中小型林窗,表现为随早晨到下午的时间增加,大林窗ST最高的时间为12点到下午2点,在林窗与非林窗中,AT与RH呈显著负相关关系。因此,不同大小林窗显著影响微环境因子,且LI对5个方向的环境因子影响较大。结果发现土壤物理性质除SCP和STP外,其他土壤物理性质与林窗大小具有显著性差异。林窗大小通常能够提高土壤物理性质,尤其是小和大林窗,表明林窗土壤比非林窗更适合植物生长。因此,大林窗显著影响林窗多数土壤物理性质的空间异质性。随不同大小林窗和不同季节变化,多数土壤化学性质有所不同。林窗大小影响土壤化学性质,与冬季相比,夏季对林窗土壤化学性质影响更大。研究表明林窗可能影响土壤化学性质但不同大小林窗具有不规则的响应。小林窗的土壤pH值显著低于中林窗,而中林窗土壤OM、TN、TC和C/N比最低,大林窗最高。小林窗的土壤pH值显著低于中林窗,而中林窗土壤OM、TN、TC和C/N比最低,大林窗最高。不同大小林窗土壤TP和TK具有相同变化模式,表现为随林窗增大而增大。与其他林窗相比,小林窗土壤AP和AK最高。冬季土壤OM、TP、TK、AP、UA、CA、TN、TC和C/N比的平均值高于夏季。土壤全氮、全碳、C/N比和土壤有机质具有显著相关性。大林窗内土壤有机质含量最高,表明大林窗土壤对植物生长具有较高的养分供给潜力。此外,土壤有机质与土壤pH值具有显著负相关关系。而在研究区内土壤pH的范围属于强酸性可能影响植物对养分的有效利用。土壤化学性质的空间异质性随季节变化。土壤pH变化较小,而林窗和非林窗内土壤OM含量适中。土壤TN和TC具有相同的变异值,但土壤C/N比的变异值差异较小。在林窗和非林窗内土壤TP、TK、AP、AK和HN的变异性适中。每个土壤化学性质的空间异质性具有不同的模式,主要取决于林窗特性和其影响因素。研究林窗土壤化学性质的空间异质性为林窗管理和物种保护提供基础数据。每个林窗都有其特定的微环境进而影响物种生长。当林窗形成后光照产生变化。结果发现,林窗内LI与ST、AT显著正相关,与RH呈显著负相关,而非林窗则相反。不同大小林窗的LI具有显著性差异,大林窗内LI均值最高,同时小林窗内LI均值最低。每个林窗LI的空间异质性不同,取决于地形、坡向和每个方向树木生长的位置。在大中型林窗内,LI与SLA具有显著负相关关系(r =-0.248,p = 0.04和r=-0.264,p = 0.008)。在所有的方向上,SLA随LI增加而增加。林窗大小影响Chla、Chlb、TChl和CAR平均值随季节变化。夏季叶绿素含量最高值出现于小林窗,叶绿素含量最低值出现于非林窗,而冬季叶绿素最高值出现于中林窗。此外,夏季对中林窗不同方向的Chla和TChl具有一定影响。由于可溶性糖和淀粉是十分灵敏的参数,因此未发现不同大小林窗影响物种可溶性糖和淀粉。不同大小林窗K含量受夏季和冬季影响,而P含量受冬季影响。不同大小林窗对C和N含量无影响。夏季影响可溶性蛋白的平均值,冬季影响SOD(U/g)酶活性,而林窗大小对其他酶活性无显著影响。运用RDA分析夏季和冬季叶片性状和环境变化表明夏季叶片性状与环境的相关性强于冬季。结果表明,与冬季相比,夏季环境对叶片性状的影响更大。p值表明夏季土壤化学性质与叶片性状的关系强于土壤物理性质。此外,夏季土壤化学性质的p值比冬季更显著。本研究区中夏季是植物生长的季节,可能植物对环境因子的响应强于冬季。结果发现格氏栲数量与林窗面积呈显著正相关关系(= 0.815,p=0.007)。格氏栲数量估计使用线性回归模型为:格氏栲数量=0.124×林窗面积+10.597(R2 = 0.664,p = 0.007)。大林窗内格氏栲数量高于小林窗(p = 0.031)。林窗中心的幼苗数量和大小与其他方位具有显著性差异(p= 0.041和p = 0.017)。然而,格氏栲与环境的相互作用十分复杂,主要取决于物种生态位转化。在格氏栲自然保护区内,与非林窗相比,林窗能够促进物种多样性和改变环境。林窗能够影响微环境,对季节具有持续波动和变化。林窗影响土壤物理-化学性质。林窗土壤组成比非林窗更好。林窗比非林窗具有更高的土壤土壤蓄水能力。土壤物理-化学性质的空间异质性为林窗管理提供基础数据。不同大小林窗的方位内,与非林窗相比,LI影响微环境和SLA。此外,叶片SLA与N、P含量具有显著正效应。研究结果表明林窗中心SLA的均值最低。林窗大小对叶片性状具有不同影响。每个叶片性状受物种、年龄、季节与环境因子等影响。本研究中很少物种受不同大小林窗环境因子的影响,是因为这些物种的叶片样本受数量限制。光照强度影响一些物种的SLA和叶绿素,而对于研究林窗对其的影响,本研究中叶片酶活性不是很好的参数。林窗能够促进格氏栲幼苗更新,格氏栲幼苗需要林窗促进更新,尤其是大林窗。对物种保护而言,林窗中心最适合格氏栲幼苗更新。研究为格氏栲天然林的管理和保护提供依据。
[Abstract]:A forest window is an area where old trees are killed, insects, certain diseases or lightning strikes, wind or storms blow down, or other fallen trees are knocked down. The emergence of a forest window increases the dynamics of the forest. Therefore, the forest window is important for maintaining the forest ecosystem. When the canopy is open to form a forest window, the forest has a small climate, light intensity, soil temperature, temperature and soil. The natural forest of Castanopsis kankam in Fujian, China, is a subtropical evergreen broad-leaved forest with the dominance of Castanopsis kankam (an average age of more than 100 years), Castanopsis Castanopsis, Pinus massoniana and Schima superba, and the highest purity of the natural forest. Many researchers are studying this species. Research on the natural forest window of Castanopsis kankam. The results showed that different sizes of forest windows and forest windows had different soil air temperature, relative humidity and soil water content. The environmental conditions were also affected by the seasons. The seed germination and seedling settlement of Castanopsis kankam may be affected by different microtopography. The decrease of seedlings and young trees makes the population of Castanopsis fargesii declining and the age structure of the population is not sustainable. The main reason is the effect of seed germination, the inadequacy of seedlings and the influence of human interference. The effect of the window size on the microenvironment was still unknown, and the mechanism of seedling regeneration and its response to the microenvironment were unknown. Therefore, the effects of the forest windows on the microenvironment and environmental factors affecting the leaf traits and the response to the microenvironment were explored. The purpose of this study was to investigate the effects of the forest windows on the microenvironment dynamics of the white days, and 2) to reveal the forest windows. The influence of size on soil chemical and physical properties; 3) investigate the effects of light intensity on microenvironment and leaf traits; 4) investigate the response of the leaf characters to the forest microenvironment; 5) investigate the influence of the size of the forest window and the different positions in the window on the regeneration of Castanopsis kankam. The results show that two photos are taken in each window center through the fish eye lens, 9 forest windows were measured by hemispherical image method. The maximum forest window area was 216.72m2, the smallest window area was 30.28 m2., according to the area of forest window, 9 forest windows were divided into 3 different sizes of forest windows (30-50 m2), middle (50-100 m2), Dalin window (150 m2), Kobayashi Yukimie broken and large middle forest. The window was produced by the tree. At the same time, the non forest window of 15 m x 15 m was set as the control. The 3 m x 3 m grid was set in the whole forest window and the non forest window as the sampling point. In the whole forest window, the microenvironmental factors were recorded every 2h from 8 to 6 p.m. and the microenvironmental factors included the soil surface temperature (ST0), the soil depth was 5cm temperature (ST5), soil depth (ST5) and soil. The soil depth is 10cm (ST10), air temperature and humidity (AT), light intensity (LI) and relative humidity (RH). Data from 15-25 days of June 2014 and 5-15 days of January 2015. The spatial model of soil physical and chemical properties and soil enzyme activity of 9 forest windows and non forest windows was introduced. The size and microenvironment of forest windows were investigated in the forest window. Leaf traits were collected in the 5 directions of 5 m x 5 m in the forest window and the non forest window. The leaf traits were collected in winter and summer (2 cmDBH, height 2-5 M.). The selected leaf traits included leaf area (LA), leaf dry weight (LDM), specific leaf area (SLA), chlorophyll a (Chla), chlorophyll b (Chlb), and total leaves. Green content (TChl), carotenoid (CAR), soluble sugar content, starch content, nitrogen content (N), carbon content (C), phosphorus content (P), potassium content (K) and leaf enzyme activity. On species management and protection, it is discussed whether the forest window may promote the regeneration of young seedlings of Castanopsis fargesii and investigate the best position of seedling regeneration in the forest window. The five directions of the south, the East, the north and the West investigate the base diameter, height and quantity of the four stages (trees, seedlings, shrubs and seedlings) of Castanopsis kankam (trees, seedlings, shrubs and seedlings). The results are as follows: the microenvironment varies with time. In each window, from 10 a. m. to 2 p.m., the heart LI is the strongest in the forest window. Except for the north of Dalin window, the other forest windows are north of the north. LI and ST showed significant positive correlation between LI and ST in the South and east direction. Unlike middle and small forest windows, the highest time of Dalin window was from 12 to 2 p.m. in the morning to afternoon. In the forest window and the non forest window, there was a significant negative correlation between AT and RH. Therefore, the different size of the forest windows significantly affected the microenvironment. LI has great influence on the environmental factors in the 5 directions. It is found that the physical properties of soil are significantly different from the size of the forest windows except SCP and STP. The size of the forest window usually improves the physical properties of the soil, especially the small and Dalin windows, indicating that the forest window soil is more suitable for the plant growth than that of the non forest window. Therefore, the Dalin window is more suitable for the plant growth. The spatial heterogeneity of most soil physical properties of the forest windows was significantly affected. The chemical properties of most soils were different with different sizes of forest windows and different seasons. The size of the forest windows influenced the chemical properties of the soil. Compared with the winter, the chemical properties of the soil were more influenced by the summer. The soil pH value of the small forest window was significantly lower than that of the middle forest window, while the medium window soil OM, TN, TC and C/N were the lowest, and the Dalin window was the highest. The pH value of the soil in the Xiaolin window was significantly lower than that of the middle forest window, while the middle forest window soil OM, TN, TC and C/N were the lowest, and the Dalin window was the highest. The soil TP and TK had the same variation pattern as the TK window. The performance was increased with the increase of forest windows. Compared with other forest windows, the soil AP and AK were highest in the small forest windows. The average value of soil OM, TP, TK, AP, UA, CA, TN, TC and C/N ratio in winter was higher than that in the summer. The soil total nitrogen, total carbon, C/N ratio and soil organic matter were significantly correlated. The soil organic matter content in the Dalin window was the highest, indicating that the Dalin window soil was grown for plants. There is a high potential for nutrient supply. In addition, soil organic matter and soil pH value have a significant negative correlation. In the study area, the range of soil pH may affect the effective utilization of nutrients to the plant. The spatial heterogeneity of soil chemical properties varies with the season. The soil pH change is smaller, and the soil OM content in the forest window and the non forest window. Moderate. Soil TN and TC have the same variation value, but the variation of soil C/N ratio is small. The variability of soil TP, TK, AP, AK and HN in the forest window and the non forest window is moderate. The spatial heterogeneity of the chemical properties of each soil has different patterns, mainly depending on the properties of the forest windows and its influencing factors. The space of the chemical properties of the forest windows is studied. Heterogeneity provides the basic data for forest window management and species protection. Each window has its specific microenvironment to affect the growth of species. As the light changes after the formation of the window, the results show that the LI in the window is significantly positively correlated with the ST and AT, and has a significant negative correlation with the RH, but the non forest window is the opposite. The LI of the different forest windows has significant differences. In Dalin window, the LI mean value is the highest and the LI mean in the forest window is the lowest. The spatial heterogeneity of each window LI is different, depending on the terrain, the slope direction and the location of the trees in each direction. In the large and medium window, the LI and SLA have a significant negative correlation (R =-0.248, P = 0.04 and r= -0.264, P = 0.008). In all directions SLA increases with the increase. The average value of Chla, Chlb, TChl and CAR changed with season. The highest chlorophyll content in summer appeared in the forest window, the lowest chlorophyll content appeared in the non forest window, and the highest chlorophyll value appeared in the middle forest window in winter. In addition, in summer, the Chla and TChl in different directions of the middle and forest windows were influenced by the soluble sugar and lake. The K content of different size forest windows was influenced by summer and winter, and the content of P was affected by winter. The contents of C and N were not affected by different sizes of forest windows. In summer, the average value of soluble protein, the activity of SOD (U/g) and the size of the forest window in winter were influenced by the average value of the soluble protein. The correlation of leaf traits and environment in summer and winter showed that the correlation between leaf traits and environment was stronger than winter. The results showed that compared with winter, the effect of summer environment on leaf traits was greater.P value than that of soil physics in summer, which showed that the relationship between soil chemical properties and leaf traits was stronger than that in soil physics in summer. In addition, the p value of soil chemical properties in summer is more significant than that in winter. The summer is the season of plant growth in this study area, and the response of plants to environmental factors is stronger than that in winter. The results show that the number of Castanopsis kankam is positively correlated with the area of forest window (= 0.815, p=0.007). The number of Castanopsis extract is estimated to be a linear regression model: Grignard The number of =0.124 of Castanopsis fargesii was +10.597 (R2 = 0.664, P = 0.007). The number of Castanopsis Castanopsis in Dalin window was higher than that of the small forest window (P = 0.031). The number and size of the seedlings in the center of the forest window were significantly different from other azimuth (p= 0.041 and P = 0.017). However, the phase interaction of Castanopsis kankam and the environment was very complex, mainly depending on the transformation of species niche. In the natural reserve of Castanopsis kankam, forest windows can promote species diversity and change the environment compared with non forest windows. Forest windows can affect microenvironment, fluctuate and change continuously. Forest windows affect soil physical and chemical properties. The composition of forest windows is better than that of non forest windows. Forest windows have higher soil soil storage capacity than non forest windows. The spatial heterogeneity of soil physical and chemical properties provides basic data for forest window management. Compared with non forest windows, LI affects microenvironment and SLA., and leaves SLA and N, P content has significant positive effect. The results show that the mean value of SLA in the center of forest window is the lowest. The size of forest window has different effects on the leaf traits. Leaf traits are influenced by species, age, season and environmental factors. In this study, few species are affected by the environmental factors of different sizes of trees, because the leaf samples of these species are limited by the number of leaves. Light intensity affects SLA and chlorophyll of some species. It is a good parameter. The forest window can promote the regeneration of Castanopsis kankam seedlings. The seedlings of Castanopsis kankam need to be updated with forest windows, especially the Dalin window. For species protection, the forest window center is the most suitable for the regeneration of Castanopsis kankam seedlings. The research provides the basis for the management and protection of the natural forest of Castanopsis kankanii.
【学位授予单位】：福建农林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S718.5
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本文编号：2034671