排序方式： 共有105条查询结果，搜索用时 15 毫秒
1.
Leaf functional traits are widely used to detect and explain adaptations that enable plants to live under various environmental conditions. This study aims to determine the difference in leaf functional traits among four forest types of Pinus massoniana coniferous and broad‐leaved mixed forests by leaf morphological, nutrients, and stoichiometric traits in the subtropical mountain, Southeastern China. Our study indicated that the evergreen conifer species of P. massoniana had higher leaf dry matter content (LDMC), leaf C content, C/N and C/P ratios, while the three deciduous broad‐leaved species of L. formosana, Q. tissima, and P. strobilacea had higher specific leaf area (SLA), leaf N, leaf P nutrient contents, and N/P ratio in the three mixed forest types. The results showed that the species of P. massoniana has adapted to the nutrient‐poor environment by increasing their leaf dry matter for higher construction costs thereby reducing water loss and reflects a resource conservation strategy. In contrast, the three species of L. formosana, Q. tissima, and P. strobilacea exhibited an optimized resource acquisition strategy rather than resource conservation strategy in the subtropical mountain of southeastern China. Regarding the four forest types, the three mixed forest types displayed increased plant leaf nutrient contents when compared to the pure P. massoniana forest, especially the P. massoniana–L. formosana mixed forest type (PLM). Overall, variation in leaf functional traits among different forest types may play an adaptive role in the successful survival of plants under diverse environments because leaf functional traits can lead to significant effects on leaf function, especially for their acquisition of nutrients and use of light. The results of this study are beneficial to reveal the changes in plant leaf functional traits at the regional scale, which will provide a foundation for predicting changes in leaf traits and adaptation in the future environment. 相似文献
2.
云南省哀牢山中山湿性常绿阔叶林萌生现象的初步研究 总被引：15，自引：1，他引：14
在森林树木受到人为或自然破坏以后,残留植物体的萌生是一个普遍存在的现象。据Kauffman〔1〕和Khan〔2〕等人在热带地区的研究,通过萌生形成的植株与通过种子萌发形成的植株相比,前者具有更快的生长速度,而且通过其原有的强大根系,能更有效地利用土壤中的养分资源,同时对环境也具有更强的适应能力。这些都构成了萌生植株在生长上的优势,使其在种群竞争中处于有利的地位。由此可见,萌生过程在植被恢复和自然更新中起到了重要的作用。近年来,关于植被萌生的研究在国外已得到越来越多的重视〔3～8〕,而在国内至今还未见到这方面的正式报道。… 相似文献
3.
Converting coniferous plantations to broad‐leaved forests is believed to result in increased runoff in Japan. This study examined low‐flow changes in runoff in the Tatsunokuchi–Minami catchment, located in a region with summer precipitation, caused by the conversion of a coniferous plantation to a broad‐leaved forest. We compared the flow duration curves for the coniferous plantation period with those for the broad‐leaved forest period. We observed no evidence of increased low flows according to the change in forest type. Thus, the commonly held belief was not supported by the results from a summer precipitation region with respect to low‐flow rates. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
4.
5.
南亚热带常绿阔叶林林下层植物的生物量及其测定方法的探讨 总被引：12，自引：0，他引：12
应用全收割法测定广东省鼎湖山南亚热带常绿阔叶林林下层植物生物量 ,林下植物总生物量为 12 9 58g/m2 ,其中茎、枝、叶、根的生物量占总生物量的比例约为 4 0 % ,9 0 % ,2 2 % ,2 9% .由部分实测数据建立林下植物个体生物量估算模型为W =0 0 0 4 2 ·H1 932 3.应用该模型得到的估算值 ,与收获实测值的相对误差仅为 1 8% ,具有良好的精度 .此外 ,还通过改变取样面积对该模型的适用性进行了探讨 . 相似文献
6.
Etİ E. Levİ Ayşe İ. Çakıroğlu Tuba Bucak Bent V. Odgaard Thomas A. Davidson Erik Jeppesen Meryem Beklİoğlu 《Freshwater Biology》2014,59(4):724-736
- Aquatic macrophytes are commonly used to assess the ecological condition of lakes. Little is known, however, about long‐term macrophyte dynamics in shallow lakes. In the absence of historical data, the remains of macrophytes (fruits, seeds and vegetative fragments) found in lake sediments may provide just such information. In order to interpret confidently past change in aquatic plant communities from their sedimentary remains, it is vital to establish the similarity between the contemporary and fossil assemblages.
- We investigated the relationship between present lake vegetation and plant macrophyte remains in surface sediments. Thirty‐five shallow lakes, spanning around six degrees of latitude and mostly located in the semi‐arid Mediterranean climatic zone of Turkey, were sampled for aquatic plants, surface sediment plant remains and a range of other key environmental variables.
- Around 50% of the taxa recorded in the modern vegetation were represented in the sediment. Sedimentary macrofossils of some taxa were under‐ or over‐represented relative to their frequency in the modern vegetation, for example Potamogeton spp. and Characeae, respectively. Despite this disparity, there was good agreement between the assemblage composition of the modern and sedimentary samples. Furthermore, conductivity and trophic state (as indicated by total nitrogen, total phosphorus and chlorophyll‐a) were the environmental variables most clearly correlated with both the contemporary and macrofossil assemblages in these lakes.
- We conclude that aquatic macrophyte macrofossils can be used as reliable indicators of ecological status and to determine qualitative changes in assemblages of aquatic plants consequent to environmental change (e.g. in lake trophic status and/or salinity). This may be especially useful for lakes in arid and semi‐arid Mediterranean regions, which are particularly vulnerable to hydrological constraints under climate change.
7.
Fire is a key ecological factor affecting plant dynamics. In the last few decades, fire occurrence in the Chaco region has increased noticeably, challenging the adaptive capacity of plants to regenerate after a fire. Broad‐leaved forb species have been much less studied than woody and graminoids, although they are an important component of fire dynamics. Here we analysed the germination response to heat shock of 70 and 110°C, smoke and their combination in 10 broad‐leaved herbaceous species frequently occurring in the Chaco Serrano of Córdoba province, central Argentina, including five annual (Bidens subalternans, Conyza bonariensis, Schkuhria pinnata, Tagetes minuta and Zinnia peruviana) and five perennial species (Borreria eryngioides, Sida rhombifolia, Solidago chilensis, Taraxacum officinale and Verbena litoralis). We also compared the response of annual versus perennial species. Six species had highest germination when treated with heat and smoke combined, whereas two had lowest germination under this treatment, indicating synergistic and antagonistic interaction of these factors respectively. Most of the species tolerated heat shock (i.e. germination was similar to that in control treatment), whereas others had higher germination in response to heat shock, especially under the moderate 70°C treatment. Germination was higher than control (i.e. no heat and no smoke) after smoke treatment in four species. Perennial species showed higher average germination than annuals in both heat treatments and in the control. Annual species had higher average germination for all treatments involving smoke. The high variability observed at the species level, and the limited number of species studied calls for precaution in interpreting and extrapolating results. Nevertheless, our study shows a general positive response of both perennial and annual species to fire cues, suggesting an advantage of these species for colonizing post‐fire environments, and being favoured under scenarios of increasingly frequent low‐to‐medium intensity fires. 相似文献
8.
常绿阔叶林片段中木荷凋落叶分解速率及中小型土壤节肢动物群落的结构动态 总被引：1，自引：1，他引：1
2004年6月-2006年4月,选择浙、闽、赣交界山地的4个森林片段作为研究地点,并以浙西的古田山国家级自然保护区作为连续森林对照,采用尼龙网袋法,研究了不同常绿阔叶林群落优势种木荷凋落叶的分解速率及土壤节肢动物群落的结构和动态.结果表明：5个研究地共获土壤节肢动物1050个,分属8纲23目,其中鳞翅目、膜翅目、弹尾目和双翅目占个体总数的10%以上,为该地区的优势类群.片段化对群落物种组成的影响主要体现在稀有类群的差异上.不同分解阶段各种土壤节肢动物类群优势度因其功能的不同而各异.经过2年的分解,各研究地木荷凋落叶损失量为60%～70%,研究地凋落物中土壤节肢动物的各项多样性指标均有一定的变化,且与连续森林的变化规律不一致. 相似文献
9.
长白山阔叶红松林生态价位分级与生态系统经营对策 总被引：4，自引：3，他引：4
引入生态价位概念,以长白山阔叶红松林为对象,采用层次分析法进行了生态价位划分．长白山阔叶红松林的生态系统价值评价综合指数由物理环境因素、群落结构组成、干扰状况3方面8个指标构成,包括坡度、土层厚度、土壤母质稳定性、结构盖度指数、物种多样性指数、更新力指数、优势种寿命和干扰度．采用层次分析法取得相应指标的系数;根据综合评价指数分布范围划分了3个生态价位类型,即低生态价位,综合指数1～1．874;中生态价位,综合指数1．874～2．749;高生态价位,综合指数2．749～3．623;对典型样地进行了生态价位分级,分析了各个生态价位类型森林的主要特征,据此提出了相应的生态系统管理对策,即高生态价位阔叶红松林采用封禁保护型自然经营,中生态价位阔叶红松林采用生态修复型半自然经营,低生态价位阔叶红松林采用近自然生态重建型经营。 相似文献
10.
Xiaofeng Fang Guochun Shen Qingsong Yang Heming Liu Zunping Ma David C. Deane Xihua Wang 《植被学杂志》2017,28(2):379-388