Variation of morphological and leaf stoichiometric traits of two endemic species along the elevation gradient of Mount Kenya, East Africa

2020 ◽  
Vol 13 (6) ◽  
pp. 785-792
Author(s):  
Antony N Waigwa ◽  
Brian Njoroge Mwangi ◽  
Gituru R Wahiti ◽  
Fred Omengo ◽  
Yadong Zhou ◽  
...  

Abstract Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mountains. Methods In this study, we assessed the variation of the morphological traits, including plant height, leaf area, leaf thickness, leaf dry weight, specific leaf area and the leaf stoichiometry traits nitrogen, carbon and phosphorous of the two endemic species D. keniensis and L. gregoriana. We further explored the relations of these morphological traits to soil organic carbon, soil total nitrogen, soil phosphorous, annual mean temperature, annual mean precipitation, annual total solar radiation, water vapor pressure and the topographic variables aspect, slope and hill shade along the elevation gradient. Ninety 10 m × 10 m sampling plots were set up along the elevation gradient ranging from 3500 to 4300 m. We used 1 km × 1 km grid cells to rasterize our study area in ArcGIS 10.5 for easy access to data pertaining to the climate of each elevation band. We performed linear regression of the morphological and leaf stoichiometric traits with elevation as explanatory variable. We conducted correlation analysis on the morphological and leaf stoichiometric traits with climatic, soil and topographic variables along the elevation gradient. Important Findings Dendrosenecio keniensis had wool-like pubescent leaves while L. gregoriana had mucilage packed succulent and waxy cuticle leaves to avoid freezing. Both species exhibited reduced metabolic rates as shown by the low leaf phosphorous content. Our results also showed that changes in morphology and leaf stoichiometry were determined by a combination of climate, soil and topographic variables that change along elevation on Mount Kenya. The observed variations in the morphological and leaf stoichiometric traits of D. keniensis and L. gregoriana, which grow side by side along the elevation gradient, were interpreted as adaptation to the harsh environmental conditions.

2021 ◽  
Vol 22 (10) ◽  
Author(s):  
Benyamin Lakitan ◽  
Kartika Kartika ◽  
Laily Ilman Widuri ◽  
Erna Siaga ◽  
Lya Nailatul Fadilah

Abstract. Lakitan B, Kartika K, Widuri LI, Siaga E, Fadilah LN. 2021. Lesser-known ethnic leafy vegetables Talinum paniculatum grown at tropical ecosystem: Morphological traits and non-destructive estimation of total leaf area per branch. Biodiversitas 22: 4487-4495. Talinum paniculatum known as Java ginseng is an ethnic vegetable in Indonesia that has also been utilized as a medical plant. Young leaves are the primary economic part of T. paniculatum, which can be eaten fresh or cooked. This study was focused on characterizing morphological traits of T. panicultaum and developing a non-destructive yet accurate and reliable model for predicting total area per leaf cluster on each elongated branch per flush growth cycle. The non-destructive approach allows frequent and timely measurements. In addition, the developed model can be used as guidance for deciding the time to harvest for optimum yield. Results indicated that T. paniculatum flourished rapidly under wet tropical conditions, especially if they were propagated using stem cuttings. The plants produced more than 50 branches and more than 800 leaves, or on average produced more than 15 leaves per branch at the age of nine weeks after planting (WAP). The zero-intercept linear model using a combination of two traits of length x width (LW) as a predictor was accurate and reliable for predicting a single leaf area (R2 = 0.997). Meanwhile, the estimation of total area per leaf cluster was more accurate if three traits, i.e., number of leaves, the longest leaf, and the widest leaf in each cluster were used as predictors with the zero-intercept linear regression model (R2 = 0.984). However, the use of a single trait of length (L) and width (W) of the largest leaf within each cluster as a predictor in the power regression model exhibited moderately accurate prediction at the R2 = 0.883 and 0.724, respectively.


Author(s):  
Vivek K. Verma ◽  
Tarun Jain

The disease occurrence phenomena in plants are season-based which is dependent on the presence of the pathogen, crops, environmental conditions, and varieties grown. Some plant varieties are particularly subject to outbreaks of diseases; on the other hand, some are opposite to them. Huge numbers of diseases are seen on the plant leaves and stems. Diseases management is a challenging task. Generally, diseases are seen on the leaves or stems of the plant. Image processing is the best way for the detection of plant leaf diseases. Different kinds of diseases occur because of the attack of bacteria, fungi, and viruses. The monitoring of leaf area is an important tool in studying physiological capabilities associated with plant boom. Plant disorder is usually an unusual growth or dysfunction of a plant. Sometimes diseases damage the leaves of plants.


2017 ◽  
Vol 76 (s1) ◽  
Author(s):  
Paolo Villa ◽  
Monica Pinardi ◽  
Viktor R. Tóth ◽  
Peter D. Hunter ◽  
Rossano Bolpagni ◽  
...  

Macrophytes are important elements of freshwater ecosystems, fulfilling a pivotal role in biogeochemical cycles. The synoptic capabilities provided by remote sensing make it a powerful tool for monitoring aquatic vegetation characteristics and the functional status of shallow lake systems in which they occur. The latest generation of airborne and spaceborne imaging sensors can be effectively exploited for mapping morphologically – and physiologically – relevant vegetation features based on their canopy spectral response. The objectives of this study were to calibrate semi-empirical models for mapping macrophyte morphological traits (i.e., fractional cover, leaf area index and above-water biomass) from hyperspectral data, and to investigate the capabilities of remote sensing in supporting macrophyte monitoring and management. We calibrated spectral models using in situ reflectance and morphological trait measures and applied them to airborne hyperspectral imaging data, acquired over two shallow European water bodies (Lake Hídvégi, in Hungary, and Mantua lakes system, in Italy) in two key phenological phases. Maps of morphological traits were produced covering a broad range of aquatic plant types (submerged, floating, and emergent), common to temperate and continental regions, with an error level of 5.4% for fractional cover, 0.10 m2 m-2 for leaf area index, and 0.06 kg m-2 for above-water biomass. Based on these maps, we discuss how remote sensing could support monitoring strategies and shallow lake management with reference to our two case studies: i.e., by providing insight into spatial and species-wise variability, by assessing nutrient uptake by aquatic plants, and by identifying hotspot areas where invasive species could become a threat to ecosystem functioning and service provision.


2020 ◽  
Author(s):  
Ulrich E Stegmann

Abstract Background and Aims The study of intraspecific trait variation (ITV) in plants has a long history, dating back to the fourth century BC. Its existence was widely acknowledged by the end of the 18th century, although systematic and experimental studies commenced only a century later. However, the historiography of ITV has many gaps, especially with regard to early observations and visual documents. This note identifies an early depiction of plant ITV. Methods The botanical works of Johann Wolfgang von Goethe (1749–1832), a German writer and naturalist, were subjected to close reading. This included all publications and unpublished sources related to botany between 1785 and 1832 (e.g. notes, drafts, diaries, letters, drawings). This material is accessible in the multi-volume historical-critical edition of Goethe’s studies in natural science (Leopoldina-Ausgabe). Key Results A diary entry from 9 September 1786 described changes in leaf morphology along an elevation gradient in the Bavarian Alps. The leaves of an unidentified species of willow (Spix sp.) and gentian (Gentiana sp.) were said to become narrower with increasing elevation; leaves also stood further apart on twigs, and the latter became thinner. A crude drawing of two willow twigs illustrated the differences. Goethe conjectured that the differences were due to environmental conditions. Conclusions Goethe’s notes were anecdotal, and it is unclear whether the observed plant individuals actually belonged to the same species. Nevertheless, the notes represent an early and clear articulation of the hypothesis that changes in environmental conditions can cause ITV in a natural plant population. The drawing may be the earliest visual record of environmentally caused plant ITV in the wild.


Plants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 118 ◽  
Author(s):  
Xu Cao ◽  
Qiudi Shen ◽  
Chunqiong Shang ◽  
Honglei Yang ◽  
Li Liu ◽  
...  

Physiological and morphological traits have a considerable impact on the biomass production of fast-growing trees. To compare cultivar difference in shoot biomass and investigate its relationships with leaf functional traits in mulberry, agronomic traits and 20 physiological and morphological attributes of 3-year-old mulberry trees from eight cultivars growing in a common garden were analyzed. The cultivars Xiang7920, Yu711, and Yunsang2 had higher shoot fresh biomass (SFB), which was closely associated with their rapid leaf expansion rate, large leaf area, and high stable carbon isotope composition (δ13C). Conversely, the cultivars 7307, Husang32, Wupu, Yunguo1, and Liaolu11 were less productive, and this was primarily the result of slower leaf expansion and smaller leaf size. Growth performance was negatively correlated with leaf δ13C and positively correlated with the total nitrogen concentration, indicating that a compromise exists in mulberry between water use efficiency (WUE) (low δ13C) and high nitrogen consumption for rapid growth. Several morphological traits, including the maximum leaf area (LAmax), leaf width and length, petiole width and length, leaf number per shoot, and final shoot height were correlated with SFB. The physiological traits that were also influential factors of shoot biomass were the leaf δ13C, the total nitrogen concentration, and the water content. Among the studied leaf traits, LAmax, leaf δ13C, and concentrations of chlorophyll a and b were identified as the most representative predictor variables for SFB, accounting for 73% of the variability in SFB. In conclusion, a combination of LAmax, leaf δ13C, and chlorophyll should be considered in selection programs for high-yield mulberry cultivars.


2009 ◽  
Vol 42 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Chitra Bahadur BANIYA ◽  
Torstein SOLHØY ◽  
Yngvar GAUSLAA ◽  
Michael W. PALMER

AbstractThis study of elevation gradients of lichen species richness in Nepal aimed to compare distribution patterns of different life-forms, substratum affinities, photobiont types, and Nepalese endemism. Distribution patterns of lichens were compared with elevational patterns shown by a wide range of taxonomic groups of plants along the Nepalese Himalayan elevational gradient between 200–7400m. We used published data on the elevation records of 525 Nepalese lichen species to interpolate presence between the maximum and minimum recorded elevations, thereby giving estimates of lichen species richness at each 100-m elevational band. The observed patterns were compared with previously published patterns for other taxonomic groups. The total number of lichens as well as the number of endemic species (55 spp.) showed humped relationships with elevation. Their highest richness was observed between 3100–3400 and 4000–4100m, respectively. Almost 33% of the total lichens and 53% of the endemic species occurred above the treeline (>4300m). Non-endemic richness had the same response as the total richness. All growth forms showed a unimodal relationship of richness with elevation, with crustose lichens having a peak at higher elevations (4100–4200m) than fruticose and foliose lichens. Algal and cyanobacterial lichen richness, as well as corticolous lichen richness, all exhibited unimodal patterns, whereas saxicolous and terricolous lichen richness exhibited slightly bimodal relationships with elevation. The highest lichen richness at mid altitudes concurred with the highest diversity of ecological niches in terms of spatial heterogeneity in rainfall, temperature, cloud formation, as well as high phorophyte abundance and diversity implying large variation in bark roughness, moisture retention capacity, and pH. The slightly bimodal distributions of saxicolous and terricolous lichens were depressed at the elevational maximum of corticolous lichens.


2010 ◽  
Vol 56 (No. 4) ◽  
pp. 194-199 ◽  
Author(s):  
M. Kabir ◽  
M.Z. Iqbal ◽  
M. Shafiq ◽  
Z.R. Farooqi

The effects of lead on root, shoot and seedling length, leaf area, number of leaves, plant circumference, seedling dry weight, root/shoot and leaf area ratios of <I>Thespesia populnea</I> L. were determined in greenhouse under natural environmental conditions with and without phytotoxic metal ions at 5, 10, 15, 20, and 25 µmol/l. Lead treatments have a strong influence on the growth and development of <I>T</I>. <I>populnea</I> by reducing significantly (<I>P</I> &lt; 0.05) all the above parameters. Lead treatment at 5–25 µmol/l produced significant (<I>P</I> &lt; 0.05) effects on seedling and root length, plant circumference and seedling dry weight of <I>T</I>.<I> populnea,</I> while lead treatment at 10–25 µmol/l produced significant (<I>P</I> &lt; 0.05) effects on shoot length, number of leaves and leaf area as compared to control. Tolerance in <I>T</I>.<I> populnea</I> seedling at 25 µmol/l of lead treatment was lowest as compared to all other treatments.


2021 ◽  
Author(s):  
Michael Le Pepke ◽  
Thomas Kvalnes ◽  
Peter Sjolte Ranke ◽  
Yimen G. Araya-Ajoy ◽  
Jonathan Wright ◽  
...  

1.Environmental conditions during early-life development can have lasting effects on individual quality and fitness. Telomere length (TL) may correlate with early-life conditions and may be an important mediator or biomarker of individual quality or pace-of-life, as periods of increased energy demands can increase telomere attrition due to oxidative stress. Thus, knowledge of the mechanisms that generate variation in TL, and the relation between TL and fitness, is important in understanding the role of telomeres in ecology and life-history evolution. 2.Here, we investigate how environmental conditions and morphological traits are associated with early-life TL and if TL predicts natal dispersal probability or components of fitness in two populations of wild house sparrows (Passer domesticus). 3.We measured morphological traits and blood TL in 2746 nestlings from 20 cohorts (1994-2013) and retrieved data on weather conditions. We monitored population fluctuations, and individual survival and reproductive output using field observations and genetic pedigrees. We then used generalized linear mixed-effects models to test which factors affected TL in early-life, and if TL predicted dispersal propensity, or was associated with recruitment probability, mortality risk, or reproductive success.4.We found a negative effect of population density on TL, but only in one of the populations. There was a curvilinear association between TL and the maximum daily North Atlantic Oscillation (NAO) index during incubation, suggesting that there are optimal weather conditions that result in the longest TL. Dispersers tended to have shorter telomeres than non-dispersers. TL did not predict survival, but we found a tendency for individuals with short telomeres to have higher annual reproductive success.5.Our study showed how early-life TL is shaped by effects of growth, weather conditions and population density, supporting that environmental stressors negatively affect TL in wild populations. In addition, TL may be a mediator or biomarker of individual pace-of-life, with higher dispersal rates and annual reproduction tending to be associated with shorter early-life TL in this study. However, clear associations between early-life TL and individual fitness seems difficult to establish and may differ between different populations in the wild.


2018 ◽  
Vol 45 (2) ◽  
pp. 92-101
Author(s):  
Masoomeh Allahnouri ◽  
Farhad Ghasemi Aghbash ◽  
Iman Pazhouhan

AbstractThe aim of this study was to evaluate the traffic-related effects on morphological and anatomical traits of Fraxinus rotundifolia and Morus alba along the Malayer-Hamedan road. In the study area, populations of two species of F. rotundifolia (30 individual trees) and M. alba (30 individual trees) were selected for sampling. The results showed that the leaf and stomata dimensions at distances near to the roadside were significantly lower compared to longer distances from the road. For F. rotundifolia, the number of veins showed the lowest plasticity, while in case of M. alba, the stomata length (P = 0.52) and the number of veins (P = 0.54) showed the lowest plasticity related to the environmental conditions. Results of discriminant analysis for population grouping for the two species of F. rotundifolia and M. alba confirmed the accuracy of grouping 74.8% and 79.5%, respectively. In case of trees that were farther away from the road, guard and epidermal cells were located at the same level. We found that the leaf stomata in M. alba were closed more than in F. rotundifolia at the same distance. Totally, the results of this research show that the air pollution stress impacted the tree morphological traits. From the two species, F. rotundifolia was more resistant in terms of pollution stress.


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