共查询到11条相似文献，搜索用时 15 毫秒
1.
克隆植物不同年龄分株间可以通过生理整合作用相互传递资源, 实现资源共享。施肥可以改变林地资源状况, 进而可能影响分株间的整合作用及不同年龄分株间的生长关系。该文采用标准主轴(SMA)估计法和多元回归分析, 对不同施肥管理下大型克隆植物毛竹(Phyllostachys edulis)种群不同年龄分株(1年生分株、3年生分株和5年生分株)间的胸径(DBH)关系进行了研究, 探讨毛竹不同年龄分株DBH大小关系对施肥的响应。结果表明: 连续5年施肥有效地增加了毛竹1年生分株的DBH, 而施肥1年处理下, 1年生分株DBH与3年生分株和5年生分株平均DBH差异不显著(p > 0.05)。1年生分株与3年生分株和5年生分株DBH之间的SMA斜率为0.88-1.10, 均与1.00不存在显著差异(p > 0.05), 表现为等速生长关系。施肥1年和连续施肥5年没有改变不同年龄分株DBH之间的SMA斜率, 但连续5年施肥导致SMA的y轴截距显著增大(p < 0.001), 即在3年生分株和5年生分株DBH相同的情况下, 连续5年施肥使1年生分株具有更大的DBH增长量。采用多元线性逐步回归分析发现, 毛竹1年生分株的DBH大小在很大程度上受3年生分株DBH大小的影响, 而连续5年施肥可增强5年生分株对1年生分株DBH大小的影响。 相似文献
2.
《植物生态学报》2017,41(11):1177
Aims Recent studies have shown that artificial addition of biochar is an effective way to mitigate atmospheric carbon dioxide concentrations. However, it is still unclear how biochar addition influences soil respiration in Phyllostachys edulis forests of subtropical China. Our objectives were to examine the effects of biochar addition on the dynamics of soil respiration, soil temperature, soil moisture, and the cumulative soil carbon emission, and to determine the relationships of soil respiration with soil temperature and moisture.Methods We conducted a two-year biochar addition experiment in a subtropical P. edulis forest from 2014.05 to 2016.04. The study site is located in the Miaoshanwu Nature Reserve in Fuyang district of Hangzhou, Zhejiang Province, in southern China. The biochar addition treatments included: control (CK, no biochar addition), low rate of biochar addition (LB, 5 t·hm-2), medium rate of biochar addition (MB, 10 t·hm-2), and high rate of biochar addition (HB, 20 t·hm-2). Soil respiration was measured by using a LI-8100 soil CO2 efflux system.Important findings Soil respiration was significantly reduced by biochar addition, and exhibited an apparent seasonal pattern, with the maximum occurring in June or July (except LB in one of the replicated stand) and the minimum in January or February. There were significant differences in soil respiration between the CK and the treatments. Annual mean soil respiration rate in the CK, LB, MB and HB were 3.32, 2.66, 3.04 and 3.24 μmol·m-2·s-1, respectively. Compared with CK, soil respiration rate was 2.33%-54.72% lower in the LB, 1.28%-44.21% lower in the MB, and 0.09%-39.22% lower in the HB. The soil moisture content was increased by 0.97%-75.58% in LB, 0.87%-48.18% in MB, and 0.68%-74.73% in HB, respectively, compared with CK. Soil respiration exhibited a significant exponential relationship with soil temperature and a significant linear relationship with combination of soil temperature and moisture at the depth of 5 cm; no significant relationship was found between soil respiration and soil moisture alone. The temperature sensitivity (Q10) value was reduced in LB and HB. Annual accumulative soil carbon emission in the LB, MB and HB was reduced by 7.98%-35.09%, 1.48%-20.63%, and -4.71%-7.68%, respectively. Biochar addition significantly reduced soil carbon emission and soil temperature sensitivity, highlighting its role in mitigating climate change. 相似文献
3.
《植物生态学报》2017,41(4):418
Aims Soil total organic carbon and labile organic carbon are important indicators in evaluating soil quality. Mulching is widely applied to promote the emergence of bamboo shoot in winter time through stand management. Yet the consequences of mulching on soil quality in Phyllostachys edulis have not been well studied. We aim at the quantitative effect of mulching duration on soil quality in P. edulis stands.
Methods Several P. edulis stands located in Huangyan District of Taizhou, Zhejiang Province of China, had been applied with mulching for 1-2 years and were used in this study to assess the mulching effects. We also selected stands without mulching treatment as the reference sites (or control, CK) for comparisons.||||Important findings Total soil organic carbon (TOC), light fraction organic matter (LFOM), and easily-oxidized carbon (EOC) contents at stands with 1-year and 2-year mulching treatments were significantly increased compared with those at the CK sites. The 1-year mulching increased TOC, LFOM and EOC by 11.2%-74.2%, 31.7%-196.9% and 5.0%-79.6%, respectively, than those of CK sites, while by 22.2%-90.8%, 36.7%-238.5%, and 21.9%-97.5% with 2-year treatment. However, the contents of water-soluble organic carbon (WSOC) changed insignificantly. Among the indicators, we found that WSOC:TOC in CK was higher than that with the mulching treatments, while EOC:TOC with 1-year treatment was higher than that with 2-year treatment, and EOC:TOC with 2-year treatment was higher than that of CK. Additionally, WSOC, EOC, and LFOM at all three treatments showed high correlations with TOC, with a higher correlation coefficient of WSOC with TOC of 0- 30 cm soil layers in CK than those with mulching treatments. The correlation coefficient of EOC and LFOM with TOC was the highest at the 2-year mulching sites. More importantly, TOC, WSOC, EOC, and LFOM were significantly (p < 0.05), or extremely significantly (p < 0.01), correlated with soil nutrient content, including total N, hydrolysis N, available P, available K, exchangeable Ca, and exchangeable Mg in all treatments. In sum, it appeared that mulching in short term can increase the contents of TOC, soil labile organic carbons and soil nutrients in bamboo soils, yielding an improved soil quality and thus can be promoted as a plausible practice for the sustainable management of P. edulis stands. 相似文献
Methods Several P. edulis stands located in Huangyan District of Taizhou, Zhejiang Province of China, had been applied with mulching for 1-2 years and were used in this study to assess the mulching effects. We also selected stands without mulching treatment as the reference sites (or control, CK) for comparisons.||||Important findings Total soil organic carbon (TOC), light fraction organic matter (LFOM), and easily-oxidized carbon (EOC) contents at stands with 1-year and 2-year mulching treatments were significantly increased compared with those at the CK sites. The 1-year mulching increased TOC, LFOM and EOC by 11.2%-74.2%, 31.7%-196.9% and 5.0%-79.6%, respectively, than those of CK sites, while by 22.2%-90.8%, 36.7%-238.5%, and 21.9%-97.5% with 2-year treatment. However, the contents of water-soluble organic carbon (WSOC) changed insignificantly. Among the indicators, we found that WSOC:TOC in CK was higher than that with the mulching treatments, while EOC:TOC with 1-year treatment was higher than that with 2-year treatment, and EOC:TOC with 2-year treatment was higher than that of CK. Additionally, WSOC, EOC, and LFOM at all three treatments showed high correlations with TOC, with a higher correlation coefficient of WSOC with TOC of 0- 30 cm soil layers in CK than those with mulching treatments. The correlation coefficient of EOC and LFOM with TOC was the highest at the 2-year mulching sites. More importantly, TOC, WSOC, EOC, and LFOM were significantly (p < 0.05), or extremely significantly (p < 0.01), correlated with soil nutrient content, including total N, hydrolysis N, available P, available K, exchangeable Ca, and exchangeable Mg in all treatments. In sum, it appeared that mulching in short term can increase the contents of TOC, soil labile organic carbons and soil nutrients in bamboo soils, yielding an improved soil quality and thus can be promoted as a plausible practice for the sustainable management of P. edulis stands. 相似文献
4.
为揭示毛竹(Phyllostachysedulis)快速生长期茎秆中的光合碳同化特征及其在不同节间的变化规律,以毛竹笋竹茎秆为材料,测定不同节间光合色素含量、核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)、磷酸烯醇式丙酮酸羧化酶(PEPC)、苹果酸脱氢酶(NADP-MDH)、NADP-苹果酸酶(NADP-ME)、磷酸烯醇式丙酮酸羧激酶(PEPCK)以及丙酮酸磷酸双激酶(PPDK)活性。结果显示,茎秆中叶绿素a、叶绿素b以及类胡萝卜素含量随节间升高均呈下降趋势,叶绿素a/b比值呈逐渐上升趋势;随着节间的升高,茎秆中Rubisco、PEPC和PPDK活性在第1–10节间显著下降,之后酶活性降幅逐渐减缓;NADP-ME活性在第1–13节间呈显著下降趋势,之后酶活性趋于平稳;NADP-MDH活性在第1–25节间显著下降。PEPC/Rubisco活性比值随节间升高而不断增加,其范围介于18.37–65.09之间,明显大于典型C3植物中的活性比值。上述结果表明,茎秆不同节间的光合碳同化能力存在明显差异,中、下部节间生长相对较快;茎秆中存在多种C4酶且活性较高,这为此时期茎秆中存在C4光合途径提供了有力证据。 相似文献
5.
Hydraulic and mechanical stem properties affect leaf-stem allometry in mango cultivars 总被引：2，自引：0，他引：2
Leaf size-stem size allometric relationships are important features of biomass allocation in plants and are affected by biological functions linking the two organs. They have been studied at specific and supraspecific levels, but not at the infraspecific level. It was hypothesized that allometric relationships link leaf size and stem size at the cultivar level, and are cultivar-specific in relation to distinctive functional stem traits: hydraulic conductivity and mechanical strength. Allometric relationships between leaf size and stem size were established for 3 yr, using the standardized major axis method, on current-year branches, composed of one to 16 growth units, for four mango (Mangifera indica) cultivars characterized by contrasting growth habits. The hydraulic and mechanical stem properties of these cultivars were also measured. The slopes of the relationships were similar among cultivars, but not the y-intercepts. Different y-intercepts in the stem mass vs branch cross-sectional area relationship and in the leaf mass vs stem mass relationship were related to mechanical and to hydraulic stem properties, respectively. These results showed that leaf-stem allometry in mango cultivars was shaped by hydraulic and mechanical stem properties, supporting a functional interpretation of the relationship between leaf and stem dimensions. 相似文献
6.
《植物生态学报》2017,41(6):683
Aims The aim of this study was to investigate the effects of alkaline stress on primary, secondary metabolites and metabolic pathways in the roots of wheat (Triticum aestivum). The results were used to evaluate the physiological adaptive mechanisms by which wheat tolerated alkali stress.Methods A pot experiment was carried out in the greenhouse. For each plastic pot, five wheat seeds were planted. After germination, seedlings were allowed to grow under controlled water and nutrient conditions for two months, then seedlings were exposed to alkaline stress (NaHCO3-Na2CO3) for 12 days. The relative growth rate (RGR), absolute water content (AWC), metal elements, free cations and metabolites were measured.Important findings The alkaline stress caused the reduction of RGR and AWC. Alkaline stress caused a rapid increase of Na content with the concurrent decrease in K and Cl content, resulting in inhibited metal element accumulation and an ionic imbalance. In the present study, alkaline stress strongly enhanced Ca accumulation in wheat roots, suggesting that an increased Ca concentration can immediately trigger the salt overly sensitive (SOS)-Na exclusion system and reduce Na-associated injuries. Also, 70 metabolites, including organic acids, amino acids, sugars/polyols and others, behaved differently in the alkaline stress treatments according to a GC-MS analysis. The metabolic profiles of wheat were closely associated with alkaline-stress conditions. Alkaline stress caused the accumulation of organic acids, accompanied by the depletion of sugars/polyols and amino acids. Organic acids could play a central role in the regulation of intracellular pH by accumulating vacuoles to neutralize excess cations. Glycolysis and amino acid synthesis in roots were inhibited under salt stress while prolonged alkaline stress led to a progressive tricarboxylic acid (TCA) cycle. The severe negative effects of alkaline stress on sugar synthesis and storage may reflect the toxic levels of Na+ accumulating in plant cells in a high-pH environment, implying that the reactive oxygen species detoxification capacity was diminished by the high pH. A lack of NO3- in wheat roots can decrease synthase enzyme activities, limiting the synthesis of amino acids. Under salt stress, the TCA cycle and organic acid accumulation increased, but glycolysis and amino acid synthesis were inhibited in roots. Thus, energy levels and high concentrations of organic acids may be the key adaptive mechanisms by which wheat seedlings maintain their intracellular ion balance under alkaline stress. 相似文献
7.
《植物生态学报》1958,44(8):791
不同的草原利用方式(围封、放牧和割草等)随着大气氮沉降的不断加剧, 改变了凋落物输入量。凋落物作为连接地上-地下碳循环过程的关键环节, 对草原生态系统生产力和碳循环过程影响显著。氮是草原生产力的主要限制因子, 凋落物输入量的变化对草原生态系统结构和功能的影响仍缺乏长期实验证据支持。该研究在内蒙古半干旱典型草原建立一个凋落物输入变化和氮添加控制实验平台, 通过连续6年对群落生产力和功能群组成的监测, 研究了凋落物添加与去除和氮添加对半干旱草原群落生产力和功能群组成的影响。研究发现: 1)凋落物输入量增加和氮添加均显著提高了群落生产力, 在对照和氮添加处理下, 凋落物去除处理导致生产力分别降低了8.4%和7.6%, 而凋落物添加处理使生产力分别提高了10.7%和6.3%; 2)不同植物功能群对凋落物输入变化和氮添加的响应存在差异, 导致群落功能群结构发生变化。随着凋落物输入量增加和氮添加, 群落优势功能群多年生禾草(包括多年生丛生禾草和多年生根茎禾草)的生物量显著提高, 对群落生产力的贡献增加, 在群落中的优势地位增强; 而另一优势功能群多年生杂类草生物量对凋落物和氮添加处理均无显著响应, 进而导致在氮添加处理下其对群落生物量的贡献比例显著降低; 3)凋落物输入主要改善土壤水分状况, 而氮添加则主要通过提高土壤养分含量, 促进群落生产力, 并通过影响主要功能群生物量, 导致群落结构发生变化。以上结果表明, 适当的草原管理方式如围封禁牧和降低放牧强度等都能通过增加凋落物的输入来提高草原生产力, 维持生态系统稳定性。而适量的氮等养分添加管理也有助于提高草原生产力, 促进其恢复。 相似文献
8.
Wen‐Yong Guo Carla Lambertini Loc Xuan Nguyen Xiu‐Zhen Li Hans Brix 《Ecology and evolution》2014,4(24):4567-4577
Compared with non‐invasive species, invasive plant species may benefit from certain advantageous traits, for example, higher photosynthesis capacity and resource/energy‐use efficiency. These traits can be preadapted prior to introduction, but can also be acquired through evolution following introduction to the new range. Disentangling the origins of these advantageous traits is a fundamental and emerging question in invasion ecology. We conducted a multiple comparative experiment under identical environmental condition with the invasive haplotype M lineage of the wetland grass Phragmites australis and compared the ecophysiological traits of this invasive haplotype M in North America with those of the European ancestor and the conspecific North American native haplotype E lineage, P. australis ssp. americanus. The invasive haplotype M differed significantly from the native North American conspecific haplotype E in several ecophysiological and morphological traits, and the European haplotype M had a more efficient photosynthetic apparatus than the native North American P. australis ssp. americanus. Within the haplotype M lineage, the introduced North American P. australis exhibited different biomass allocation patterns and resource/energy‐use strategies compared to its European ancestor group. A discriminant analysis of principal components separated the haplotype M and the haplotype E lineages completely along the first canonical axis, highly related to photosynthetic gas‐exchange parameters, photosynthetic energy‐use efficiency and payback time. The second canonical axis, highly related to photosynthetic nitrogen use efficiency and construction costs, significantly separated the introduced P. australis in North America from its European ancestor. Synthesis. We conclude that the European P. australis lineage was preadapted to be invasive prior to its introduction, and that the invasion in North America is further stimulated by rapid post‐introduction evolution in several advantageous traits. The multicomparison approach used in this study could be an effective approach for distinguishing preadaptation and post‐introduction evolution of invasive species. Further research is needed to link the observed changes in invasive traits to the genetic variation and the interaction with the environment. 相似文献
9.
Growth rates of cultured first-year bonefish Albula sp. averaged 0·32 mm day−1 . Maximum theoretical growth (±95% CI) was 278 (±11·2) mm L S (sexes combined), confirming that Albula sp. from the Gulf of California grow less than other species in the' vulpes 'complex. 相似文献
10.