| The present study, we investigated morphological, growth and photosynthetic traits of seedlings of two liana species (Bauhinia tenuiflora, tendril climbing; Byttneria aspera, stem climbing) under controlled conditions, with aim to understand relationships between climbing mechanisms and capacity of resource acquirement, at three light levels (4%, 35% and 100% sunlight) and two soil nutrient treatments (high, low). The results reveled that light significantly affected most of the phenotypic traits of two liana species, however, soil nutrient just affected fewer phenotypic traits. Low light promoted the growth of aboveground. Seedlings grown under low light level had higher SLA, SMR and LARm, however, more biomass was invested into belowground growth when grown under high light and they had higher RMR in order to improve the ability of absorption. Meanwhile, the ability for light capturing was improved by increased branch numbers. RGR increased at high light level as well as Pmax and NAR. When grown under the same treatment, Bauhinia tenuiflora often had significant higher RGR than Byttneria aspera. We can concluded that light instead of soil nutrient is more important for the distribution of lianas. With specialized climbing tissues, B. tenuiflora might have wider distribution than B. tenuiflora in the field, for it have higher phenotypic plasticity.In another study, we explored the leaf photosynthetic characteristics, pigment content, chlorophyll fluorescence, reflectance indices and anatomical traits of seedlings of 8 liana species and 5 tree species common in tropical rainforest. We found: In low light, lianas had lower photosynthetic capacity, but they had greater increase (trees, 61.5%; lianas, 86.4%) and higher photosynthetic rate under high light level, they had higher light compensation point (LCP) and light saturated point (LSP), so they were more like shade-intolerance species. Both lianas and trees species had the similar diurnal changes of chlorophyll fluorescence (△F/ Fm′, quantum yield of PSⅡphotochemistry; ETR, electron transport rate; NPQ, non-photochemical quenching; Fv/Fm, maximum efficiency of PSⅡphotochemistry), they protected the photosynthetic apparatus by reversible inactivation for PSⅡin part. Pegia nitida Colobr and Bauhinia tenuiflora were less inhibited by mid-day high light, for there were no significant changes of chlorophyll fluorescence for them during day. Pigment content per unit area decreased under higher light level. In contrast to trees, lianas had higher chlorophyll a, chlorophyll b, total chlorophyll content, carotenoid content per unit area and higher ratio of chlorophyll a/ b. When compared to the other studies, the reflectance indices show no or weak correlationship both with chlorophyll fluorescence indices (PRI vs△F/ Fm′;△P RI vs NPQ) and pigment parameters (Chl NDI vs Chl total; SIPI vs Car/ Chl total;△PRI vs Car/ Chl total), which might result from the distinctive leaf structure and traits among different species. Lianas had larger specific leaf area (SLA) than trees though they had thicker leaves, which indicating that lianas had less dense leaves.In order to advance our understanding on the relationships between lianas and their supporting trees, we manipulated four different competition treatments such as AN (all neighbors), RN (root neighbors), SN (shoot neighbors), and NN (no neighbors) in order to investigate the effects of the above- and belowground competition of a liana on the growth and biomass allocation of seedlings of three tropical tree species grown under two light levels (4% and 35% of full sun light). The competition from lianas substantially reduced the growth of tree seedlings and the relative importance of above- and belowground competition differed in two light levels. In the low light, SN resulted in more reduction than RN, however, in high light, RN instead of SN caused more reduction in growth of tree seedlings. The biomass allocation into the various organs changed among the competition combinations and was significantly altered by light and competition. Different competition combinations resulted in distinctive morphological traits, seedlings often grew with small diameter, lower stem, less leaf numbers and smaller leaf area, but the slenderness (stem length / diameter) changed little. We also estimated the species richness, abundance, size-class distribution, climbing mode and the percentage of trees (DBH≧5cm) infested by lianas in valley and ridge plots in a tropical montane rain forest in Mengsong, southern Yunnan. A total of 64 liana species representing 30 families were recorded. There were averages of 95.7 and 57 lianas with dbh≧ 1 cm in the valley and in the ridge per 0.1 ha, respectively. A greater proportion of lianas was twiners (57 % of density) while 3% of all were tendril climbers. Approximately 43.7% and 28.6% of trees (dbh≧5 cm) were liana-infested in the valley and ridge plots. Compared to other tropical Asian tropical forests, the density of lianas in Mengsong is very high though the diversity of species is relatively low.
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