Storage dynamics of fallen trees in a mixed broadleaved and Korean pine forest

A study of the storage dynamics in the mixed broadleaved and Korean pine forests was carried out in the Changbai Mountains, Jilin Province, P. R. China. The modifying law of fallen trees was the storage dynamics of the existing fallen trees and the annual input in the mixed broadleaved and Korean pine forest. The current storage of fallen trees was 16.25 t昲m-2 in the initially, but after 100 years, 85% of the storage in dry weight was decomposed, and little material was left after 300 years. The average annual input of fallen trees was 0.6 t昲m-2and it increased with time to 31.0 t昲m-2after 200 years, which was maintained until the climax community ended. The total storage of fallen trees increased in the early stage. The decomposition of fallen trees eventually reached equilibrium with storage being identical with the annual input of fallen trees.

Influence of canopy on precipitation and its nutrient elements in broadleaved/Korean pine forest on the northern slope of Changbai Mountain

The precipitation distribution quantity of canopy in broadleaved/Korean pine forest was measured during the growing season (Jun.–Sept.) in 2001 in the Changbai Mountain, Jilin Province, P. R. China. Results indicated that the amounts of stemflow, throughfall, and interception were 37.39, 322.12 and 109.69 mm, accounting for 7.97%, 68.65% and 23.38% of the total rainfall, respectively. The rate of stemflow was higher in Jul. and Aug. than other months. The rate of throughfall dropped off from Jun. to Sept., however, rate of interception changed contrarily from 19.43% to 31.02% during the growing season. According to our analysis, the concentration of nutrient elements were arranged as Ca>Mg>N>K>Fe>P>Cu>Mn for rainfall, K>N>Mg>Ca>P>Fe>Mn>Cu for throughfall, and Mn>P>K>Cu>Fe>N>Mg>Ca for being leached through canopy. Nutrients concentration in stewflow and throughfall changed significantly when rainfall passed canopy, and concentration of all elements increased except for Ca and Mg.

A preliminary study on in-stream large woody debris in broadleaved and Korean pine forest in Changbai Mountain, Northeast China

This study was conducted in Erdaobaihe River passing through the broadleaved and Korean pine forest located on the north slope of Changbai Mountain. In-stream large woody debris (LWD) in two segments of the river channel was investigated with base diameter, top diameter, length, and decay class. To study relationship between in-stream LWD and adjacent riparian forest, species of each log of LWD in segment 1 was identified, and the riparian forest was examined by setting a 32m?4 m quadrat consisting of twelve 8m?m small quadrats. The results showed that, in segment 1, in-stream LWD loading was 1.733 m3/100m or 10.83 m3hm-2, and in segment 2, it was 1.709m3/100m or 21.36 m3hm-2. In-stream LWD in decay class III and IV were accounted for a high proportion, which was different from that in the broadleaved and Korean pine forest, and the possible reason might be different decomposing velocities due to different decomposing conditions. Logs of LWD in stream and living trees in riparian forest declined as diameter increased, and it was in a reverse J-shaped distribution except logs of LWD in segment 1 in the first diameter class. Volumes of LWD in stream and living trees in riparian forest increased as diameter increased, and it was in a typical J-shaped distribution. Loading and species component of in-stream LWD were correlative to status of riparian forest to a certain extent, and there also existed difference. Comparing the correlation and difference was helpful to study on dynamic of the riparian forest.

Species composition and minimum sampling area of a riparian mixed broadleaved-Korean pine forest in Changbai Mountain Nature Reserve

Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changbai Mountain were investigated by using field data collected from eight sampling transects perpendicular to the Erdaobai River channel. Two kinds of species-area saturation curves were used to examine the relationship between species number and minimum sampling area. The results showed that riparian gymnosperms accounted for a high proportion of all gymnosperms in the Changbai Mountain Nature Reserve while riparian ferns and angiosperms accounted for a relatively low proportion. The average minimum sampling areas of riparian forest that included 60%, 80%, and 90% of the community species pool were about 85, 185, and 328 m 2 , respectively; while those for nonriparian forest were about 275, 390, and 514 m 2 , correspondingly.

Long-term changes in radial growth of seven tree species in the mixed broadleaf-Korean pine forest in Northeast China:Are deciduous trees favored by climate change?

The role of the temperate mixed broadleaf-Korean pine forest(BKF)in global biogeochemical cycles will depend on how the tree species community responds to climate;however,species-specific responses and vulner-abilities of common trees in BKF to extreme climates are poorly understood.Here we used dendrochronological meth-ods to assess radial growth of seven main tree species(Pinus koraiensis,Picea jezoensis,Abies nephrolepis,Fraxinus mandshurica,Phellodendron amurense,Quercus mongolica,and Ulmus davidiana)in an old-growth BKF in response to climate changes in the Xiaoxing’an Mountains and to improve predictions of changes in the tree species compo-sition.Temperature in most months and winter precipita-tion significantly negatively affected growth of P.jezoensis and A.nephrolepis,but positively impacted growth of P.koraiensis and the broadleaf species,especially F.mandshu-rica and U.davidiana.Precipitation and relative humidity in June significantly positively impacted the growth of most tree species.The positive effect of the temperature during the previous non-growing season(PNG)on growth of F.mandshurica and Q.mongolica strengthened significantly with rapid warming around 1981,while the impact of PNG temperature on the growth of P.jezoensis and A.nephrolepis changed from significantly negative to weakly negative or positive at this time.The negative response of radial growth of P.jezoensis and A.nephrolepis to precipitation during the growing season gradually weakened,and the negative response to PNG precipitation was enhanced.Among the studied species,P.koraiensis was the most resistant to drought,and U.davidiana recovered the best after extreme drought.Ulmus davidiana,P.jezoensis and A.nephrolepis were more resistant to extreme cold than the other species.Climate warming generally exacerbated the opposite growth patterns of conifer(decline)and broadleaf(increase)spe-cies.Deciduous broadleaf tree species in the old-growth BKF probably will gradually become dominant as warming continues.Species-specific growth-climate relationships should be considered in future models of biogeochemical cycles and in forestry management practices.

Dynamics of profiles and storage of carbon dioxide in broadleaved/Korean forest in Changbai Mountain

CO2 concentrations at different heights in a broadleaved/Korean forest (with a mean height of 26 m) were measured with infrared gas analyzer IRGA (model 2250D, LI-COR Inc. and LI-COR, 820) from Aug. to Oct. of 1999, Apr. to Jul. of 2000, and from Aug. 2002 to Sept. 2003. Based on the collected dada, the diurnal and seasonal dynamics of profiles and storage of carbon dioxide in the forest were analyzed. The diurnal CO2 profiles showed that the vertical distribution of CO2 concentration were different for daytime and nighttime, and the CO2 concentration was highest close to forest floor, no matter at daytime and nighttime. The seasonal profiles of CO2 showed that stratification in the canopy was evident during growth season. CO2 concentrations at different heights (60 m to 2.5 m) had a little change in March, with a difference of 10 mmolmol-1, but had a significant change in July, with a difference of 60 mmolmol-1. In July, there also existed a greater gradient of CO2 concentrations at canopy (22, 26 and 32 m), with a difference of 8 mmolmol-1. The calculated total storage (ΔC/Δt ) of CO2 in the air column with height of 40 m beneath eddy covariance instrument was negative, and made a little contribution to NEE.

Soil carbon dioxide fluxes of a typical broad-leaved/Korean pine mixed forest in Changbai Mountain, China

The forest ecosystem plays an important role in the global carbon cycling. A study was conducted to evaluate soil CO2 flux and its seasonal and diurnal variation with the air and soil temperatures by using static closed chamber technique in a typical broad-leaved/Korean pine mixed forest area on the northern slope of Changbai Mountain, Jilin Province, China. The experiment was carried out through the day and night in the growing season (from June to September) in situ and sample gas was analyzed by a gas chromatograph. Results showed that the forest floor was a large net source of carbon, and soil CO2 fluxes had an obvi-ous law of seasonal and diel variation. The soil CO2 flux of broad-leaved/Korean pine mixed forest was in the range of 0.302.42 mmol穖-2穝-1 with the mean value of 0.98 mmol穖-2穝-1. An examination on the seasonal pattern of soil CO2 emission suggested that the variability in soil CO2 flux could be correlated with variations in soil temperature, and the maximum of mean CO2 flux occurred in July ((1.27±23%) mmol穖-2穝-1) and the minimum was in September ((0.50±28%) mmol穖-2穝-1). The fluctuations in diel soil CO2 flux were also correlated with changes in soil temperature; however, there existed a factor for a time lag. Soil CO2 flux from the forest floor was strongly related to soil temperature and had the highest correlation with temperature at 6-cm depth of soil. Q10 values based on air temperature and soil temperature of different soil depths were at the ranges of 2.09–3.40.

Dynamics of nitrogen nutrition of coexisting dominant trees in mixed broad-leaved/Korean pine forest

Chemical analysis of ammonium, nitrate and total nitrogen in tree leaves and roots and anin-vivo bioassay for nitrate reductase activity (NRA) were used to monitor the seasonal variations in nitrogen assimilation among four coexisting dominant tree species, includingPinus koraiensis, Tilia amurensis, Fraxinus mandshurica andAcer mono, in a virgin mixed broad-leaved/Korean pine (Pinus koraiensis) forest. The soil study included individual horizons of L+F (0–5 cm), Ah (5–11 cm) and Aw (11–25 cm). All four species had nitrate and ammonium in their roots and leaves, and also NRA in leaves. This indicated that these coexisting species were adapted to ammonium + nitrate nutrition. A negative correlation existed between nitrate use and ammonium use. Ammonium concentration was higher than that of nitrate in tree leaves and roots, and also in soils, which indicated climax woody species had a relative preference for ammonium nutrition. There was a positive relationship between tree nitrogen nutrition use and soil nitrogen nutrient supply. Utilization of ammonium and nitrate as well as the seasonal patterns differed significantly between the species. Peaks of ammonium, nitrate, NRA and total nitrogen in one species were therefore not necessarily synchronous with peaks in other species, and which indicated a species-specific seasonal use of nitrogen. The species-specific temporal differentiation in nitrogen use might reduce the competition between co-existing species and may be an important mechanism promoting stability of virgin mixed broad-leaved//Korean pine forest.

NITROGEN NUTRIENT MECHANISM IN SECONDARY SUCCESSION PROCESS OF THE MIXED BROAD-LEAVED/ KOREAN PINE (PINUS KORAIENSIS) FOREST

Chemical and biochemical analysis methods were used to monitor the vedations of nitrogen nutrient among the dominance trees species in secondary succession process of the mixed broad - leaved/Korean pine forest on Changbai Mountains, Northeast China. Amounts of total nitrogen, anunonium and NRA in soils of virgin broad-leaved/Korean pine forest which is in climax were higher than those of secondary birch forests those are in succession Stage. The amount of nitrate was in the other hand. In climax, dominance trees species are tolerant mesophytic trees such as Pinus Koraiensis, Tilia amurensis, Acer mono and also Fraxinus mandshurica, they are all ammonium + nitrate adapted species, but they show a preference for the anunonium rather than those of the pioneer trees species in secondary birch forest, such as Populus davidiava and Betula platyphylla. Because they have more ammonium in their leaves and roots, especially Pinus koraiensis. Populus davidvana and Betula plaaphlla are intolerant trees, amounts of nitrate and total nitrogen is higher in their leaves and roots and also NRA in their leaves, so they preference for the nitrate rather than the others.In secondary birch forest, the regeneration trees species adapt their nitroggn nutrient to the variation of nitrogen nutrient situation in soil, finally they could survival well and the secondary birch forest would succession to climax. In climax, dominance trees species adapt their Nitrogen nutrient to the situation in soil and there are not strong competition in nitrogen nutrient among them, so they can coexist well and keep the climax as stable vegetation.

Recovery of species diversity after disturbance of broad-leaved Korean pine mixed forest in Changbai Mountain

Recovery of species diversity after catastrophic disturbance was influenced by a few factors, such as intensity of disturbance, availability of propagules, and the environmental conditions, In this paper, we examined pattems of species development after nearly 60a succession in bumed broad-leaved Korean pine mixed forest on northem slope of ChangbaiMountain. We aasessed the recovery of plant species diversity in 3 types of forests under the contition with gradient of soil moisture. Results revealed that recovery of plant species (liversity varied greatly under different environmental conditions.Species richness of secondary forests greatly related to the site condition. Secondary birch forest on mesic site had the greatest number of plant species and the following was poplar-birch forest and larch-birch forest.Most of characteristic taxa couldbe found in birch forest after 60a succession. For larch-birch forest on hydra site, most of climax species were still not able to invade, so it had the lowest species diversity.

A Retrospect on Studies of Broadleaved/Korean Pine Forests

It is well--known that broadlcaved/Korean pine forests distribute in the areanear the broad seas in the cast Asia.TheStudy history or the forests is coincided withthat of its exploitation and destroying.

Photosynthetic characteristics of dominant tree species and canopy in the broadleaved Korean pine forest of Changbai Mountains

Based on the light-photosynthesis response measurement at leaf level, combined with over- and under-canopy eddy covariance measurements, research on photosynthetic characteristics of single trees and forest canopy was conducted. The relationship between light intensity and photo-synthetic rates for leaves and canopy can be well fitted by a non-rectangular hyperbola model. Mongolian oak presented a high light compensation point, Lcp (28μmol·m-2·s-1), a light saturation point Lsp (>1800μmol·m-2·s-1), and a maximal net photosynthetic rate Pmax (9.96μmol·m-2·s-1), which suggest that it is a typical heliophilous plant. Mono maple presented the highest apparent quantum efficiencyα(0.066) but the lowest, Lcp (16μmol·m-2·s-1), Lsp (=800μmol·m-2·s-1), and Pmax (4.51μmol·m-2·s-1), which suggest that it is heliophilous plant. Korean pine showed the lowestαvalue but a higher Pmax, which suggest that it is a semi-heliophilous plant. At the canopy level, the values of both or and Pmax approached the upper limit of reported values in temperate forests, while Lcp was within the lower limit. Canopy photosynthetic characteristics were well consistent with those of leaves. Both showed a high ability to photosynthesize. However, environmental stresses, especially high vapor pressure deficits, could significantly reduce the photosynthetic ability of leaves and canopy.

Modeling diameter distribution of the broadleaved-Korean pine mixed forest on Changbai Mountains of China

The broadleaved-Korean pine mixed forest is a native vegetation in the Changbai Mountains, northeast China. The probability density functions including the normal, negative exponential, Weibull and finite mixture distribution, were used to describe the diameter distributions of the species groups and entire forest stand. There is a strong correlation between parameters and mean DBH except the shape parameters in the mixture distribution. The diameter classes of species and entire forest stand showed not negative exponential but normal and "S" distribution. The mixture function was better than normal and Weibull to describe the model distribution. The location parameter had an effect on the estimated frequency in the first diameter class, when the estimated location parameter was bigger than the lower limit of the first diameter class.

Meteorological control on CO_2 flux above broad-leaved Korean pine mixed forest in Changbai Mountains

The impacts of temperature, photosynthetic active radiation (PAR) and vapor pressure deficit (VPD) on CO2 flux above broad-leaved Korean pine mixed forest in the Changbai Mountains were studied based on eddy covariance and meteorological factors measurements.The results showed that, daytime CO2 flux was mainly controlled by PAR and they fit Michaelis-Menten equation. Meanwhile VPD also had an influence on the daytime flux. Drier air reduced the CO2 assimilation of the ecosystem, the drier the air, the more the reduction of the assimilation. And the forest was more sensitive to VPD in June than that in July and August. The respiration of the ecosystem was mainly controlled by soil temperature and they fit exponential equation. It was found that this relationship was also correlated with seasons; respiration from April to July was higher than that from August to November under the same temperature. Daily net carbon exchange of the ecosystem and the daily mean air temperature fit exponential equation. It was also found that seasonal trend of net carbon exchange was the result of comprehensive impacts of temperature and PAR and so on. These resulted in the biggest CO2 uptake in June and those in July and August were next. Annual carbon uptake of the forest ecosystem in 2003 was -184 gC. m-2.

长白山主要林分物种多度分布与性状分布的关系

【目的】探究长白山地区群落物种的多度分布格局及其驱动过程,以及多度分布与性状分布之间的关系,为当地森林经营与修复策略的制定提供理论依据。【方法】以长白山不同林分类型的3块5.2 hm2(次生山杨白桦林、次生针阔混交林、原始红松紫椴林)和1块5 hm2原始阔叶红松林固定监测样地为研究对象,通过采集样地内木本个体的6个关键功能性状(叶面积、比叶面积、叶片厚度、最大树高、叶片氮含量、叶片磷含量),分析样地的物种多度分布格局、功能性状分布格局以及二者之间的关系。【结果】不同林分类型中通过统计检验的模型种类各异,但所有最优模型均为统计模型。在性状分布格局中,最大树高、比叶面积和叶磷含量在4块样地均呈现正态分布。然而,功能性状分布格局转化得到的物种分布格局模型显示,尽管部分模型通过了统计检验,但与多度分布结果拟合度不高。【结论】在长白山地区,物种多样性的形成并非主要由随机过程驱动,而是受到竞争作用的显著影响,这决定了演替过程中群落物种组成的变化情况。虽然功能性状分布与物种多度分布之间存在一定的联系,但直接通过群落水平性状分布格局推断物种多度的方法尚不准确。

阔叶红松林林木与林分生长对采伐干扰的响应

提升森林质量、修复生态功能是东北阔叶红松林生态修复的核心,而阐明林木与林分生长对采伐干扰的响应机理是其中的关键。森林对采伐干扰的响应会受到空间尺度、时间尺度以及干扰程度等因素的综合影响。以往的研究侧重于比较不同采伐处理下林木生长的相对大小,而忽视了不同恢复时间下,林木和林分生长随干扰程度的变化。以吉林蛟河阔叶红松林采伐样地为对象,基于连续四次样地调查数据(2011、2013、2015、2018年),分别探讨了林木和林分生长在不同恢复阶段对不同程度采伐干扰的响应,并通过构建分段模型确定采伐干扰阈值。结果显示:林木和林分生长对采伐干扰的响应并不一致,采伐促进了林木生长,并且林木生长量随采伐强度的升高而升高;采伐降低了林分生产力,林分生产力随采伐强度的升高而降低。林木和林分生长对采伐干扰的响应存在时滞效应:林木和林分生长在采伐后两年内并无显著变化,而在采伐三年后才发生明显变化。此外,分段模型的结果显示:当保留木断面积为21.6 m^(2)/hm^(2)时,林分生产力最高,表明通过密度调整使阔叶红松林胸高断面积维持在21.6 m^(2)/hm^(2)附近,可使林分处于较高的生产力水平、促进森林恢复。研究结果能够为制定科学的阔叶红松林生态修复策略提供技术支撑。

胜山阔叶红松林粗木质残体空间分布格局

为探究胜山阔叶红松(Pinus koraiensis)林粗木质残体(Coarse woody debris,CWD)的形成过程及机制,采用点格局分析法对10.4 hm^(2)大型样地内不同分类的CWD的空间格局、空间关联性进行了研究。结果表明:(1)总CWD在0—7 m尺度聚集分布,7—50 m尺度随机分布。(2)腐烂等级5级CWD、倒木、伐根在所有尺度随机分布;其他CWD随尺度增大由聚集分布转为随机分布,但格局尺度不同(在2—10 m之间)。(3)大、中径级与小径级CWD在0—4 m、0—6 m尺度正相关;高腐烂等级与低腐烂等级CWD在0—5 m尺度以内正相关;枯立木与倒木在0—4 m尺度正相关;落叶松(Larix gmelinii)CWD与小径级、腐烂等级2级的红皮云杉(Picea koraiensis)CWD在0—3 m尺度正相关,与中径级、腐烂等级1、2级在13—16 m尺度负相关。胜山阔叶红松林CWD的形成是由树种特性、小尺度的个体竞争、大尺度的自然衰老、外界干扰、生境异质性等共同决定的;大、中径级对小径级CWD、先形成对后形成CWD、枯立木对倒木具有一定的正向影响,落叶松对红皮云杉CWD在小尺度有正向影响,而在稍大尺度有负面影响;在一定程度上揭示了该林型CWD的形成过程和机制。

氮添加对长白山阔叶红松林2种树木幼苗光合生理生态特征的影响

植物的光合作用是评估全球变化背景下碳循环的重要环节。目前,氮沉降增加日益明显,作为植物生长关键因子的可利用氮将对植物的光合生理生态过程产生影响。以长白山阔叶红松林主要树种红松和紫椴的幼苗为例,通过模拟氮沉降增加(氮添加量分别为0、23、46和69 kg N hm^(-2)a^(-1))的方法,利用Li-6400光合测定系统分别测算了两个树种的最大净光合速率(A_(max))、气孔导度(G_(smax))和水分利用效率(WUE)的值,并测算了叶氮含量、叶绿素含量、比叶面积、光合氮利用效率(PNUE)的值。通过分析A_(max)随不同施氮量的变化规律,同时结合其他叶片特征参数的变化,进一步探讨植物光合随氮添加的变化原因。研究结果显示:两个树种的A_(max)值在0—46 kg N hm^(-2)a^(-1)的氮添加范围内随施氮量的增加而增大,继续增加施氮量至69 kg Nhm^(-2)a^(-1)则出现下降。叶绿素含量、G_(smax)、PNUE和比叶面积在不同的氮添加水平下的变化规律与A_(max)的一致,且均与A_(max)呈显著正相关关系。叶氮含量与A_(max)的值仅在0—46 kg N hm^(-2)a^(-1)氮添加范围内呈显著正相关。A_(max)与WUE的相关关系不显著。相同氮添加水平下,氮添加对阔叶树种紫椴各生理生态参数(A_(max)、G_(smax)、叶氮含量、比叶面积、PNUE和WUE)的促进程度高于对针叶树种红松各生理生态参数的促进程度。研究结果可为评估氮沉降增加背景下我国东北地区的碳循环提供依据。

采伐对长白山阔叶红松林生态系统碳密度的影响

采伐对森林生态系统碳密度和固碳能力有重要的影响,且影响的程度因采伐强度和方式不同而有巨大差异。以长白山地区原始阔叶红松林在不同采伐方式、采伐强度干扰后形成的次生林为研究对象,通过对2007至2009年建立的11块1 hm2永久样地中植被层、凋落物层和土壤层碳密度在采伐前后变化特征的分析,研究了采伐强度与恢复时间对阔叶红松林生态系统碳密度的影响。结果表明:在短期内,采伐导致了植被层和土壤表层(0—20cm)碳密度值的减少,其中植被碳密度与采伐强度有显著的线性负相关关系(y=-0.9x+91.17,R2=0.626,P<0.01),而后,随着植被的恢复,生态系统碳密度增加,其中植被、土壤层碳密度呈显著线性正相关关系。根据植被碳密度与恢复时间之间的相关关系,确定以生态系统恢复、木材生产与固碳三者兼顾的合适采伐强度为30%,轮伐期为45a。

受干扰长白山阔叶红松林林分结构组成特征及健康距离评估

通过样地调查对不同干扰方式产生的过伐天然林、次生白桦林和人工落叶松林等群落的结构组成进行分析和分类探讨 ,并选取能够表征结构完整性和稳定性的一些指标因子 ,利用健康距离法对长白山阔叶红松林区的森林生态系统健康进行了评估实践 ,结果按顺序依次为 :原始阔叶类 0 14 <结构转换型0 2 3<结构保留型 0 32 <结构破坏型 0 33<严重干扰类型 0 4 4 <次生白桦林 0 5 3<人工落叶松林0 6 8.以期对阔叶红松林生态系统的恢复和区域林业可持续发展提供参考 .