scholarly journals Scale Change and Correlation of Plant Functional Characteristics in the Desert Community of Ebinur Lake

2021 ◽  
Vol 13 (9) ◽  
pp. 4983
Author(s):  
Hanpeng Li ◽  
Guanghui Lv ◽  
Lamei Jiang ◽  
Jinlong Wang

The difference of functional traits among different species is the basis of species coexistence in natural ecosystems, and the variation of traits among individuals within species also plays an important role in species coexistence and distribution. Taking the desert plant community of Ebinur Lake as the research object, five plant functional characteristics were measured in 13 plants of 25 quadrats in the study area. The changes of these five functional characteristics by the method of character gradient analysis and the scale variation of plant functional traits and the correlation between their environments were studied. The results showed that: (1) the range of α value of the five plant functional characteristics in the community was larger than that of β value; that is, the change of the character value of a species relative to related symbiotic species was larger than that along the average character gradient of the community. (2) The correlations between leaf thickness and leaf area as well as between leaf thickness and leaf dry matter content were the strongest with correlation coefficients. That is, the correlations between LTH and SLA as well as between LTH and LDMC were stronger than that between the two species in the community, suggesting that the development of succession had no significant effect. The strategies used by dominant species to adapt to the environment changed from high-speed growth to improving resource utilization efficiency, while the coexisting species in the same community adopted different character combinations to adapt to the common community environment.

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 793
Author(s):  
Yaxiong Zheng ◽  
Fengying Guan ◽  
Shaohui Fan ◽  
Yang Zhou ◽  
Xiong Jing

Functional characteristics reflect plant strategies and adaptability to the changing environment. Determining the dynamics of these characteristics after harvesting would improve the understanding of forest response strategies. Strip clearcutting (SC) of moso bamboo forests, which significantly reduces the cutting cost, has been proposed to replace manual selective harvesting. A comparison of restoration features shows that 8 m is the optimal cutting width. However, the precise response of functional features to the resulting harvest-created gap remains unclear. In this study, three SC plots were selected which was performed in February 2019, with three unharvested plots as a control (C). The study focused on 10 functional traits, including leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), nitrogen/phosphorus ratio (N:P), wood density (WD), fine root biomass (FRB), specific fine root length (SRL), and root length density (RLD). A one-way ANOVA was used to compare differences in functional traits and soil nutrients between treatments. Strip clearcutting significantly reduced the soil organic carbon (SOC) and total nitrogen (TN) contents (p < 0.05). In terms of functional characteristics, SC significantly decreased LA and increased LNC, LPC, and N:P (p < 0.05). However, SC had no significant effect on fine root traits (p > 0.05). This study highlighted that root trait, soil content of total phosphorus (TP) and total potassium (TK) returned to the level of uncut plots after a year’s recovery. The LPC, LNC, and N:P were negatively correlated with LA, and LDMC and WD were negatively correlated with SLA, while the effect of SC on fine root traits was limited (p > 0.05). Fine root traits (FRB, RLD, and SRL) were positively associated with SOC, TN, and TP, but negatively correlated with TK. The changes in soil nutrient content caused by the removal of biomass were normal. Increased light and the rapid growth of new trees will increase nutrient regressions; therefore, these results further confirm the feasibility of SC.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1079
Author(s):  
Martina Cardoni ◽  
Jesús Mercado-Blanco ◽  
Rafael Villar

Verticillium wilt of olive (VWO), caused by the soil-borne pathogen Verticillium dahliae, is considered one of the most important diseases affecting this tree crop. One of the best VWO management measures is the use of tolerant cultivars. Remarkably, no information is available about olive functional traits and their potential relationship with tolerance to V. dahliae. Twenty-five selected functional traits (for leaf, stem, root and whole plant) were evaluated in six olive varieties differing in their VWO tolerance level to identify possible links between this phenotype and functional traits’ variation. High intervarietal diversity was found among cultivars and several functional traits were related with VWO tolerance. Tolerant varieties showed higher leaf area, dry matter content (leaf, stem and plant) and mass fraction for stems, but lower for leaves. Significant differences were also detected for root functional traits, tolerant cultivars displaying larger fine root diameter and lignin content but smaller specific length and area of thick and fine roots. Correlations were found among functional traits both within varieties and between levels of tolerance/susceptibility to VWO. Associations were observed between biomass allocation, dry matter content and VWO tolerance. The most relevant difference between tolerant and susceptible cultivars was related to root system architecture.


2021 ◽  
Author(s):  
vivek pandi ◽  
Kanda Naveen Babu

Abstract The present study was carried out to analyse the leaf functional traits of co-occurring evergreen and deciduous tree species in a tropical dry scrub forest. This study also intended to check whether the species with contrasting leaf habits differ in their leaf trait plasticity, responding to the canopy-infestation by lianas. A total of 12 leaf functional traits were studied for eight tree species with contrasting leaf habits (evergreen and deciduous) and liana-colonization status (Liana+ and Liana−). In the liana-free environment (L−), evergreen trees had significantly higher specific leaf mass (LMA) and leaf dry matter content (LDMC) than the deciduous species. Whereas, the deciduous trees had higher specific leaf area (SLA) and mass-based leaf nitrogen concentration (Nmass). The leaf trait-pair relationship in the present study agreed to the well-established global trait-pair relationships (SLA Vs Nmass, Lth Vs SLA, Nmass Vs Lth, Nmass Vs LDMC, LDMC Vs SLA). There was no significant difference between L+ and L− individuals in any leaf functional traits studied in the deciduous species. However, evergreen species showed marked differences in the total chlorophyll content (Chlt), chlorophyll b (Chlb), SLA, and LMA between L+ and L− individuals of the same species. Deciduous species with the acquisitive strategy can have a competitive advantage over evergreen species in the exposed environment (L−) whereas, evergreen species with shade-tolerant properties were better acclimated to the shaded environments (L+). The result revealed the patterns of convergence and divergence in some of the leaf functional traits between evergreen and deciduous species. The results also showed the differential impact of liana colonization on the host trees with contrasting leaf habits. Therefore, liana colonization can significantly impact the C-fixation strategies of the host trees by altering their light environment. Further, the magnitude of such impact may vary among species of different leaf habits. The increased proliferation of lianas in the tropical forest canopies may pose a severe threat to the whole forest carbon assimilation rates.


2021 ◽  
Author(s):  
Xinxin Guo ◽  
Xiaoan Zuo ◽  
Ping Yue ◽  
Xiangyun Li ◽  
Ya Hu

Abstract Background and Aims Global changes profoundly impact on structure and function of grassland ecosystem. However, it remains unclear on the mechanism of how multiple limiting resources affect plant community primary productivity (ANPP) in desert steppe.Methods Here, we conducted an experiment to examine the effects of precipitation changes (natural and ± 50% precipitation) and nutrient addition (=N: 0 g·m-2·yr-1; +N: N 10 g·m-2·yr-1; +NPK: N/P/K each for 10 g·m-2·yr-1) on species diversity, ANPP, functional traits and soil properties. We used structural equation model (SEM) to evaluate the effects of precipitation changes and nutrient addition on ANPP.Results Increased precipitation increased species diversity and ANPP under NPK addition, NPK addition increased ANPP under increased precipitation, and the interaction of precipitation changes and nutrient addition was significant for ANPP. Drought reduced plant height and leaf dry matter content (LDMC), but increased leaf nitrogen content (LNC). ANPP was positively correlated with species richness, abundance, height and LDMC, but negatively correlated with specific leaf area (SLA) and LNC. The SEM showed increased precipitation and nutrient addition directly increased ANPP. Altered precipitation indirectly affected ANPP through its effect on abundance and SLA, while nutrient addition indirectly affected ANPP only through its effect on abundance.Conclusion The combined limitations of precipitation and multiple nutrients deserves more attention in studying the effect of global changes on productivity in arid steppe. Our results highlight the importance of species diversity and functional traits in driving short-term responses of ANPP to environmental factors in desert steppe ecosystems.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1047 ◽  
Author(s):  
Konstantinos Stefanidis ◽  
Eva Papastergiadou

Freshwater ecologists have shown increased interest in assessing biotic responses to environmental change using functional community characteristics. With this article, we investigate the potential of using functional traits of the aquatic plants to assess eutrophication in freshwater lakes. To this end we collected macrophyte and physicochemical data from thirteen lakes in Greece and we applied a trait-based analysis to first identify discrete groups of macrophytes that share common functional traits and then to assess preliminary responses of these groups to water quality gradients. We allocated 11 traits that cover mostly growth form and morphological characteristics to a total of 33 macrophyte species. RLQ and fourth corner analysis were employed to explore potential relationships between species, trait composition and environmental gradients. In addition, a hierarchical cluster analysis was conducted to discriminate groups of plants that share common trait characteristics and then the position of the groups along the environmental gradients was assessed. The results showed total phosphorus, chlorophyll-a, conductivity, pH and Secchi disk depth as main drivers of the environmental gradients. Hierarchical cluster analysis showed a clear separation of macrophyte assemblages with discrete functional characteristics that appeared to associate with different environmental drivers. Thus, rooted submerged plants were related with higher Secchi disk depth, conductivity and alkalinity whereas rooted floating-leaved plants showed a preference for enriched waters with phosphorus and nitrogen. In addition, free-floating plants were related positively with nitrogen and increased pH. Although we did not identify specific trait patterns with environmental drivers, our findings indicate a differentiation of macrophytes based on their functional characteristics along water quality gradients. Overall, the presented results are encouraging for conducting future monitoring studies in lakes focused on the functional plant trait composition, as expanding the current approach to additional lakes and using quantifiable functional characteristics will provide more insight about the potential of trait-based approaches as ecological assessment systems.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yun Wang ◽  
Yu Zhou ◽  
Xuedong Yan

As a sustainable transportation mode, high-speed railway (HSR) has been developing rapidly during the past decade in China. With the formation of dense HSR network, how to improve the utilization efficiency of train-sets (the carrying tools of HSR) has been a new research hotspot. Moreover, the emergence of railway transportation hubs has brought great challenges to the traditional train-sets’ utilization mode. Thus, in this paper, we address the issue of train-sets’ utilization problem with the consideration of railway transportation hubs, which consists of finding an optimal Train-set Circulation Plan (TCP) to complete trip tasks in a given Train Diagram (TD). An integer programming TCP model is established to optimize the train-set utilization scheme, aiming to obtain the one-to-one correspondence relationship among sets of train-sets, trip tasks, and maintenances. A genetic algorithm (GA) is designed to solve the model. A case study based on Nanjing and Shanghai HSR transportation hubs is made to demonstrate the practical significance of the proposed method. The results show that a more efficient TCP can be formulated by introducing train-sets being dispatched among different stations in the same hub.


Ecology ◽  
2016 ◽  
Vol 97 (1) ◽  
pp. 250-261 ◽  
Author(s):  
Zhenying Huang ◽  
Shuangshuang Liu ◽  
Kent J. Bradford ◽  
Travis E. Huxman ◽  
D. Lawrence Venable

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Manish Sharma ◽  
Prof. Sonu Lal

Conventional distributed arithmetic (DA) is popular in field programmable gate array (FPGA) design, and it features on-chip ROM to achieve high speed and regularity. In this paper, we describe high speed area efficient 1-D discrete wavelet transform (DWT) using 9/7 filter based new efficient distributed arithmetic (NEDA) Technique. Being area efficient architecture free of ROM, multiplication, and subtraction, NEDA can also expose the redundancy existing in the adder array consisting of entries of 0 and 1. This architecture supports any size of image pixel value and any level of decomposition. The parallel structure has 100% hardware utilization efficiency.


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