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1.
Tohno S Tohno Y Moriwake Y Azuma C Ohnishi Y Minami T 《Biological trace element research》2002,87(1-3):83-93
To elucidate compositional changes of the cardiac valves with aging, the authors investigated the relationships among element
contents in the aortic valves, in which the accumulation of calcium and phosphorus was the highest. The subjects consisted
of 10 men and 14 women, ranging in age from 65 to 102 yr. Extremely significant direct correlations were found among the contents
of calcium, phosphorus, magnesium, sodium, and zinc in the aortic valves. In contrast, significant inverse correlations were
found between the contents of sulfur and the other elements, such as calcium, phosphorus, magnesium, and sodium. It should
be noted that these correlations present in the aortic valves were very similar to those in the arteries, especially those
in the thoracic aortas. The changes of the mass ratios of Mg/Ca and Mg/P in the aortic valves were similar to those in the
thoracic aortas. As calcium and phosphorus increased in the aortic valve, the mass ratios Mg/Ca and Mg/P decreased reversely
in the aortic valve. These results suggest that the compositional change of the aortic valve is very similar to that of the
thoracic aorta. 相似文献
2.
Tohno Y Tohno S Azuma C Moriwake Y Naganuma T Ohnishi Y Minami T 《Biological trace element research》2003,96(1-3):93-107
To elucidate compositional changes of the thoracic duct with aging, the authors investigated age-related changes of elements
in the thoracic ducts in comparison with the azygos veins. The subjects consisted of 22 men and 1 woman, ranging in age from
65 to 95 yr. After ordinary dissection, the thoracic ducts and azygos veins were resected from the subjects and element contents
were determined by inductively coupled plasma-atomic emission spectrometry. It was found that calcium appeared to increase
in the thoracic duct with aging, but the other elements, such as phosphorus, sulfur, magnesium, iron, zinc, and sodium, did
not change significantly with aging. In the azygos vein, both calcium and sulfur increased significantly with aging.
Regarding the relationship among elements, extremely significant direct correlations were found among calcium, phosphorus,
sulfur, and magnesium in the thoracic ducts, except for phosphorus and magnesium contents with a very significant direct correlation.
In the azygos veins, significant direct correlations were found between calcium and sulfur contents and between sulfur and
magnesium contents. However, no significant correlations were found among calcium, phosphorus, and magnesium in the azygos
veins. These results revealed that with regard to the relationship among calcium, phosphorus, and magnesium, the thoracic
duct was similar to the arteries, but not to the azygos vein. 相似文献
3.
Setsuko Tohno Yoshiyuki Tohno Takeshi Minami Yuko Okazaki Masako Utsumi Fumio Nishiwaki Yumi Moriwake Masa-oki Yamada 《Biological trace element research》1998,62(1-2):17-23
To elucidate age-related changes of mineral contents in human veins, the relative contents (RCs) of elements in the human
internal jugular veins, superior and inferior venae cavae, and femoral veins from 27 subjects ranging from 40 to 98 yr old
were analyzed by inductively coupled plasma atomic emission spectrometry.
The average RCs of calcium in the 27 specimens were the highest in the internal jugular vein, followed in descending order
by the superior vena cava, femoral vein, and inferior vena cava.
The RCs of calcium and phosphorus in the internal jugular veins started to increase after the age of 50 yr, became the highest
in subjects in their 60s and thereafter decreased gradually. It is noted that such accumulations of minerals, similar to the
internal jugular vein, were also found in the veins, such as the superior and inferior venae cavae, and femoral vein. Accumulation
of minerals in the veins is different from that of arteries, which increase progressively by aging, but do not decrease. 相似文献
4.
Tohno Y Tohno S Mahakkanukrauh P Vaidhayakarn P Somsarp V Minami T Moriwake Y Azuma C 《Biological trace element research》2001,84(1-3):19-35
To elucidate compositional changes of arteries with aging, the authors previously investigated age-related changes of mineral
contents in the various arteries of Japanese and Japanese monkey. To examine whether there were differences between races
in regard to age-related changes of mineral contents and the relationships among element contents in the arteries, the authors
investigated the arteries of Thai. The subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr. After the
ordinary dissection at Chiang Mai University was finished, abdominal aortas, common iliac, internal iliac, and external iliac
arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry.
The contents of calcium, phosphorus, and magnesium became the highest in the fifties in the abdominal aorta, common iliac,
and external iliac arteries, whereas the contents of calcium and magnesium became the highest in the sixties in the internal
iliac artery, and decreased thereafter. In regard to relationships among element contents, it was found that there were high
correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium
in all of the abdominal aortas and three iliac arteries. The mass ratios of magnesium to calcium and phosphorus were each
similar in the abdominal aorta, common iliac, and internal iliac arteries, except for the external iliac artery, in which
it was slightly high. These revealed that as calcium and phosphorus increased in the arteries with aging, magnesium increased
in the arteries as well. The differences between the arteries of Thai and Japanese were discussed in the present article. 相似文献
5.
Moriwake Y Tohno Y Tohno S Azuma C Minami T Takano Y 《Biological trace element research》2002,88(3):215-222
To elucidate compositional changes of elements in the meniscus with aging, the authors investigated the relationships among
elements in the medial meniscus by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 16 men
and 7 women, ranging in age from 65 to 93 yr. In the left medial meniscus, extremely significant correlations were found both
between calcium and phosphorus contents and between sulfur and magnesium contents, whereas significant correlations were found
between calcium and either iron or zinc contents, between phosphorus and either iron or zinc contents, and between iron and
zinc contents. On the other hand, in the right medial meniscus, there were only an extremely significant correlation between
calcium and phosphorus contents and a significant correlation between sulfur and magnesium contents. The common finding between
the left and right medial menisci was an extremely significant correlation between calcium and phosphorus contents and a significant
correlation between sulfur and magnesium contents. 相似文献
6.
Tohno S Tohno Y Moriwake Y Azuma C Ohnishi Y Minami T 《Biological trace element research》2001,84(1-3):57-66
To elucidate the mechanism of element accumulations in the arteries with aging, the authors investigated the mass ratios among
calcium, phosphorus, and magnesium in the common iliac arteries by inductively coupled plasma-atomic emission spectrometry.
The subjects consisted of 16 men and 8 women, ranging in age from 65 to 93 yr.
It was found that there were extremely significant correlations between calcium and phosphorus contents, between calcium and
magnesium contents, and between phosphorus and magnesium contents in the common iliac arteries. In regard to the mass ratio,
although the mass ratio of calcium to phosphorus was almost constant, the mass ratios of magnesium to calcium and phosphorus
were different at early and advanced stages of the accumulation of calcium and phosphorus. It was found that both the mass
ratios of magnesium to calcium and phosphorus were higher at an early stage of the accumulation of calcium and phosphorus
in the arteries than at an advanced stage of the accumulation. 相似文献
7.
Tohno S Tohno Y Masuda M Minami T Moriwake Y Utsumi M Yamada M 《Biological trace element research》1999,70(3):233-241
It is known that a large quantity of magnesium contains bones, and the magnesium contents in spongy bones decrease gradually
with advancing age. To elucidate the relationships between a decrease of mineral contents in human bones and an accumulation
of minerals in the other human tissues, the content of magnesium was analyzed by inductively coupled plasma-atomic emission
spectrometry among human bones, arteries, veins, and cartilages in 27 subjects (17 men and 10 women). These were resected
from the subjects who died in the age range 40–98 yr. Calcanei were chosen for analysis of magnesium contents in contrast
with femoral, popliteal, and common carotid arteries, internal jugular and femoral veins, superior and inferior venae cavae,
and pubic symphyses.
The magnesium contents in the calcanei decreased gradually with aging, whereas they increased progressively in the arteries,
veins, and pubic symphyses with aging. It was found that as the magnesium contents decreased in the calcanei, they increased
in the arteries, such as the femoral, popliteal, and common carotid arteries, whereas they decreased inversely in the veins,
such as the internal jugular and femoral veins and superior and inferior venae cavae. Furthermore, as the magnesium contents
decreased in the calcanei, they hardly changed in the pubic symphyses. These suggest that magnesium released from bones is
accompanied by accumulation of magnesium in the arteries. 相似文献
8.
Yoshiyuki Tohno Setsuko Tohno Yumi Moriwake Cho Azuma Yoshiaki Ohnishi Takeshi Minami 《Biological trace element research》2001,82(1-3):21-28
To elucidate compositional changes of the arteries with aging, the authors investigated the relationships among average contents
of calcium, phosphorus, sulfur, and magnesium in the arteries by inductively coupled plasma-atomic emission spectrometry.
The arteries used were the thoracic and abdominal aortas, coronary, common carotid, anterior, middle and posterior cerebral,
vertebral, basilar, internal thoracic, axillary, radial, truncus celiacus, common, internal and external iliac, femoral, popliteal,
and umbilical arteries. It was found that high correlations were found between the average contents of calcium and phosphorus,
between the average contents of calcium and magnesium, and between the average contents of phosphorus and magnesium in the
arteries, but not between the average contents of sulfur and the other elements. These correlations revealed that as the content
of calcium and phosphorus increased in the arteries, the magnesium content increased simultaneously in the arteries, but the
sulfur content did not. It is likely that magnesium forms compounds with phosphorus in the arteries. 相似文献
9.
Summary A pot experiment was carried out in the greenhouse, on sweet-lime (Citrus aurantifolia) seedlings grown in soils with three Mg/Ca ratios: 0.33, 0.11, and 0.05. Leaf analyses showed positive correlations between Mg/Ca ratios in the medium and magnesium contents, and Mg/Ca ratios in the leaves. Using a split-root technique it has been shown that impaired magnesium uptake at the Mg/Ca ratio of 0.05 in the medium, is not due to its low magnesium contents, but rather to an excess of calcium. 相似文献
10.
Yoshida S Takano Y Moriwake Y Tohno Y Masuda M Tohno S Minami T Yamasaki M Morikawa H Yuri K 《Biological trace element research》2001,80(1):13-22
To elucidate compositional changes of the uterine tube by aging, the authors studied age-related changes of elements in human uterine tubes by inductively coupled plasma-atomic emission spectrometry. The uterine tubes were resected postmortem or surgically removed from patients with uterine myoma. It was found that the contents of calcium and magnesium increased progressively with aging in uterine tubes, whereas the contents of phosphorus and iron decreased gradually with aging. The sulfur content of uterine tubes remained constant and independent of aging. Regarding relationships between elements, significant relationships were found between calcium and magnesium contents, between phosphorus and iron contents, between phosphorus and sulfur contents, and between phosphorus and sodium contents in human uterine tubes. 相似文献
11.
Azuma C Tohno S Mahakkanukrauh P Tohno Y Ongkana N Minami T Moriwake Y Kumai T Vaidhayakarn P Yamada MO Maruyama H 《Biological trace element research》2005,105(1-3):59-70
To elucidate compositional changes of the elastic cartilage with aging, the authors investigated age-related changes of elements
in the epiglottal cartilages by inductively coupled plasma-atomic emission spectrometry. After the ordinary dissection by
medical students at Chiang Mai University was finished, the epiglottises were resected from the subjects. The epiglottal cartilages
were isolated and the element contents were determined. The subjects consisted of 11 men and 14 women, ranging in age from
39 to 92 yr old. It was found that although the extent of accumulation of calcium and phosphorus was slight, calcium and phosphorus
increased progressively in the epiglottal cartilages with aging. In contrast, sulfur, magnesium, zinc, iron and sodium did
not change significantly in them. Regarding the relationships among elements, it was found that there were significant correlations
among calcium, phosphorus, magnesium, and sodium in the epiglottal cartilages, with one exception between calcium and sodium
contents. In comparison between men and women, no significant differences were found in the predominant elements such as calcium,
sulfur, and phosphorus in the epiglottal cartilages. 相似文献
12.
Tohno S Mahakkanukrauh P Tohno Y Vaidhayakarn P Minami T Somsarp V Moriwake Y Chomsung R Azuma C 《Biological trace element research》2002,87(1-3):69-82
To examine whether there were differences between races in regard to age-related changes of mineral contents and the relationships
among element contents in the arteries, the authors investigated the coronary arteries of Thai and Japanese. The Thai subjects
consisted of 13 men and 3 women, ranging in age from 39 to 84 yr, whereas the Japanese subjects consisted of 17 men and 9
women, ranging in age from 55 to 92 yr. After the ordinary dissections at Chiang Mai University and Nara Medical University
were finished, the coronary arteries were resected and the element contents were determined by inductively coupled plasma-atomic
emission spectrometry. In the Thai, an accumulation of calcium and phosphorus began to occur in the forties and increased
markedly in the fifties, whereas in the Japanese, an accumulation of calcium and phosphorus began to occur in the seventies
and increased markedly in the nineties. The result revealed that an accumulation of calcium and phosphorus occurred earlier
in the Thai than in the Japanese. Regarding the relationships among element contents, extremely significant correlations were
found between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium
contents in both the coronary arteries of the Thai and the Japanese. As far as the coronary arteries with a very high accumulation
of calcium and phosphorus, the mass ratios of magnesium to calcium and phosphorus were lower in the coronary arteries of the
Thai in comparison with the Japanese. 相似文献
13.
Ohnishi Y Tohno S Mahakkanukrauh P Tohno Y Vaidhayakarn P Azuma C Satoh H Moriwake Y Chomsung R Minami T 《Biological trace element research》2003,96(1-3):71-92
To elucidate whether the extent of element accumulation in the arteries and cardiac valves with aging was different between
different races, the authors investigated the accumulation of elements in the arteries and cardiac valves of the Thai with
aging and the relationships among elements in the cardiac valves. After ordinary dissection at Chiang Mai University was finished,
16 arteries and 4 cardiac valves were resected and element contents were determined by inductively coupled plasma-atomic emission
spectrometry.
In the 16 arteries, the average content of calcium was the highest in the site of the abdominal aorta ramifying into the common
iliac arteries, and it decreased in the order internal iliac, coronary, abdominal aorta, common iliac, external iliac, superior
mesenteric, inferior mesenteric, thoracic aorta, brachial, radial, common carotid, subclavian, ulnar, axillary, renal, and
internal thoracic arteries. The average contents of phosphorus and magnesium in respective arteries were parallel with the
average contents of calcium, except for the coronary artery. In comparison with the arteries of the Japanese, the trend of
calcium accumulation in the arteries of the Thai was almost similar to that in the arteries of the Japanese, except for the
coronary artery and thoracic aorta. The calcium accumulation in the coronary artery was much higher in the Thai than in the
Japanese, whereas that in the thoracic aorta was lower in the Thai than in the Japanese.
Regarding elements in the cardiac valves, the calcium content increased remarkably in the seventies in the aortic valve and
in the nineties in the pulmonary valve, but it hardly increased in both the mitral and tricuspid valves with aging. The average
content of calcium was the highest in the aortic valve, and it decreased in the order pulmonary, tricuspid, and mitral valves.
Regarding the relationship among elements in the aortic valves, it was found that there were extremely significant direct
correlations among the contents of calcium, phosphorus, and magnesium, whereas there were significant direct correlations
between zinc and either calcium or phosphorus contents. Although significant correlations were found between sulfur and the
other element contents in the aortic valves of the Japanese, no significant correlations were found between them in the aortic
valves of the Thai. In the mitral valves, extremely or very significant direct correlations were found among the contents
of calcium, phosphorus, magnesium, and sulfur, with some exceptions that there were no significant correlations between phosphorus
and either magnesium or sulfur contents.
In addition, no significant correlation was found in the calcium content between the aortic valve and coronary artery in the
same individuals. 相似文献
14.
Tohno Y Tohno S Mahakkanukrauh P Azuma C Vaidhayakarn P Moriwake Y Ohnishi Y Minami T 《Biological trace element research》2003,91(3):217-230
To elucidate quantitative changes of Ca, P, and Mg in the arteries with aging, the authors investigated changes of the mass
ratios of Mg to Ca and P in the arteries of Japanese and Thai by inductively coupled plasma-atomic emission spectrometry.
The arteries of Japanese that were used were the thoracic and abdominal aortas, coronary, common iliac, internal iliac, external
iliac, and femoral arteries, in which very high accumulations of Ca and P occurred in old age. The arteries of Thai that were
used were the abdominal aorta, ramifying site of the abdominal aorta, coronary, common iliac, internal iliac, and external
iliac arteries.
It was found that there were extremely significant correlations both between Ca and Mg contents and between P and Mg contents
in all of the arteries of the Japanese and the Thai. With regard to the mass ratio, the mass ratios of Mg to Ca ranged from
1.5% to 2.1% in the six arteries of the Japanese, except for the thoracic aorta at 3.1%, at an advanced stage of atherosclerosis,
being similar to each other. In the arteries of the Thai, the mass ratios of Mg to Ca ranged from 1.9% to 3.0%, except for
the coronary artery at 0.5%, at an advanced stage of atherosclerosis.
The mass ratios of Mg to P ranged from 2.5% to 2.7% in the six arteries of the Japanese, except for the coronary artery at
1.8%, at an advanced stage of atherosclerosis. With regard to the arteries of the Thai, the mass ratios of Mg to P ranged
from 1.9% to 3.3%, except for the coronary artery at 0.7%, at an advanced stage of atherosclerosis. These results revealed
that both the mass ratios of Mg to Ca and Mg to P were almost similar among the arteries of Japanese and Thai, except for
the coronary arteries. Therefore, these results suggested that the inorganic deposits in the coronary arteries of Japanese
and Thai were similar to those in the intimal tunica of the thoracic aorta, whereas in the other arteries, they were similar
to those in the middle tunica of the thoracic aorta. 相似文献
15.
Takano Y Tohno Y Moriwake Y Tohno S Minami T Yamada MO Yuri K 《Biological trace element research》2000,74(2):117-125
To elucidate changes of the ureter with aging, the authors investigated age-related changes of element contents in human ureters.
The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. The contents of calcium, sulfur, and
iron in the ureters increased progressively with aging, whereas the contents of phosphorus and magnesium did not increase
with aging. Significant relationships were found both between calcium and sulfur contents and between calcium and iron contents
in the ureters, but not between calcium and either phosphorus or magnesium contents. It was noteworthy that a significant
relationship was also found between sulfur and iron contents in the ureters. It remains uncertain whether calcium forms a
compound with sulfur or iron in aged human ureters or not. 相似文献
16.
Naganuma T Naruse K Tohno Y Tohno S Yamasaki M Minami T Moriwake Y Morikawa H 《Biological trace element research》2004,102(1-3):73-82
To elucidate the compositional change of ligaments with aging, the authors investigated both age-related changes of elements
and relationships among elements in the round ligaments of the uterus (round ligaments) by inductively coupled plasma-atomic
emission spectrometry. The bilateral round ligaments were resected from 20 cadavers and also from the uteri removed surgically
from 11 patients bearing uterine myoma or cancer. Thirty-one subjects ranged in age from 34 to 92 yr. It was found that both
S and Mg decreased gradually in the round ligaments with aging, but Ca, P, Zn, Fe, and Al did not change significantly with
aging. Regarding the relationships among elements, very significant direct correlations were found among the contents of Ca,
P, S, and Mg in the round ligaments, whereas significant inverse correlations were found between the contents of Zn and elements,
such as Ca, P, S, and Mg. It should be noted that there was an extremely significant direct correlation between Ca and P contents
in the round ligaments. 相似文献
17.
To examine whether an accumulation of elements in the arteries with aging differs between human and animal, the authors investigated
the relationships among element contents in the arteries of the Japanese monkeys. The Japanese monkeys consisted of five males
and four females, ranging in age from 2 to 29 yr. The aorta, common and external iliac, femoral, common carotid, subclavian,
and axillary arteries were resected from the monkeys and element contents were determined by inductively coupled plasma-atomic
emission spectrometry. It was found that there were very high correlations between calcium and phosphorus contents, between
calcium and magnesium contents, and between phosphorus and magnesium contents in all of the monkey arteries. In addition,
significant correlations were found among the other element contents in some, but not all of the arteries. These results were
consistent with the foregoing findings of the human arteries. It is likely that magnesium forms compounds with phosphorus
or calcium in the monkey arteries. 相似文献
18.
Yoshiyuki Tohno Setsuko Tohno Takeshi Minami Yumi Moriwake Masako Utsumi Fumio Nishiwaki Masa-Oki Yamada 《Biological trace element research》1998,63(2):105-111
To elucidate the relationships between the decrease of mineral contents in human bones and the accumulation of minerals in
the other human tissues, the relative contents (RCs) of calcium were analyzed by inductively coupled plasma atomic emission
spectrometry among human bones, arteries, veins, and cartilages in 27 subjects (17 men and 10 women). These were resected
from subjects who died in the age range from 40 to 98 yr old. Calcanei were chosen for analysis of mineral contents in contrast
with femoral, popliteal and common carotid arteries, internal jugular veins, and pubic symphysis.
It was found that the RCs of calcium in calcanei were agreeable to association with those in both the pubic symphysis and
the femoral artery, but they were not agreeable to association with those in the popliteal and common carotid arteries, and
the internal jugular veins. This suggests that calcium released from bones is accompanied by accumulations of calcium in the
artery and cartilage. 相似文献
19.
Age-related changes of elements and relationships among elements in the common bile and pancreatic ducts 总被引:1,自引:0,他引:1
Tohno Y Tohno S Yamada MO Azuma C Moriwake Y Minami T Maruyama H Omura T 《Biological trace element research》2004,101(1):47-60
To elucidate compositional changes of the common bile and main pancreatic ducts with aging, the authors investigated age-related
changes of element contents in the common bile and pancreatic ducts by inductively coupled plasma-atomic emission spectrometry.
After ordinary dissection by medical students was finished, the common bile ducts and main pancreatic ducts (pancreatic ducts)
were resected and the element contents were determined. The Mg content increased significantly only in the pancreatic duct
with aging, but the other element contents did not change significantly in both the common bile and pancreatic ducts with
aging. Regarding the relationship among the elements, significant direct correlations were found among the contents of Ca,
P, S, and Mg in the common bile ducts, with some exceptions between P and either S or Mg contents. In the pancreatic ducts,
significant direct correlations were found between S and Mg contents and between P and Na contents. The relationships in the
elements between the common bile and pancreatic ducts were examined. It was found that there were significant direct correlations
in the Ca, Mg, and Fe contents between the common bile and pancreatic ducts; that is, as Ca, Mg, and Fe increased in the common
bile duct, they increased simultaneously in the pancreatic duct. 相似文献
20.
干热河谷区不同林龄赤桉叶中养分含量和再吸收率的比较及其线性回归分析 总被引:2,自引:0,他引:2
以种植于干热河谷区的赤桉(Eucalyptus camaldulensis Dehnh.)幼龄林、中龄林和成熟林为研究对象,分析了赤桉鲜叶和凋落叶中养分(包括N、P、K、Ca、Mg和Na)的含量和化学计量比,并计算各养分的再吸收率;在此基础上,对鲜叶和凋落叶中各养分的含量与再吸收率进行线性回归分析.结果表明:成熟林赤桉鲜叶和凋落叶的有机碳、全氮、全磷、全钾和全钠含量总体上高于幼龄林,而全钙和全镁含量则低于幼龄林;且鲜叶中的全氮、全磷、全钾、全钠和全镁含量总体上高于凋落叶,而有机碳和全钙含量则低于凋落叶.成熟林赤桉鲜叶和凋落叶的C:N比、鲜叶的N:P比和N:K比以及凋落叶的K:P比和Ca:Mg比均低于幼龄林,但其鲜叶的K:P比和Ca:Mg比及凋落叶的N:P比和N:K比则高于幼龄林;且不同林龄鲜叶的C:N比、K:P比和Ca:Mg比均低于凋落叶.各林龄赤桉叶的Ca再吸收率及幼龄林和中龄林叶的Na再吸收率均为负值,而其余养分的再吸收率均为正值;随林龄增长,N、K和Mg的再吸收率先升高后降低,而P、Ca和Na的再吸收率却先降低后升高;总体上看,赤桉叶中各养分的再吸收率从高到低依次为P、N、K、Mg、Na、Ca.线性回归分析结果表明:赤桉鲜叶的全钾和全钠含量分别与K和Na再吸收率呈极显著正相关(P<001),全钙含量与Ca再吸收率呈显著正相关(P<005);而凋落叶的全氮含量与N再吸收率呈极显著负相关,全镁含量与Mg再吸收率呈显著负相关.综合分析结果显示:林龄对赤桉叶的养分含量和再吸收率有明显影响,其保存养分的能力随林龄增长呈现先增强后减弱的趋势. 相似文献