scholarly journals Phenology of the endangered palm Ceroxylon quindiuense (Arecaceae) along an altitudinal gradient in Colombia

2021 ◽  
Vol 69 (2) ◽  
pp. 649-664
Author(s):  
Blanca Martínez ◽  
René López Camacho ◽  
Luis Santiago Castillo ◽  
Rodrigo Bernal

Introduction: Understanding the phenology of plant populations is vital for their conservation and management. We studied the vegetative and reproductive phenology of the endangered palm Ceroxylon quindiuense along an altitudinal gradient in the Central Cordillera of Colombia. Objective: We describe the leaf production rate, and flowering and fruiting cycles, and calculate food offer for the fauna, as a tool for the proper management of the palm. Methods: At each sampling site (2 400, 2 600, 2 800, 3 000 m.a.s.l.), we marked 40 adult individuals (20 pistillate, 20 staminate), which we followed bimonthly for 24 months. We studied leaf production by counting fallen leaves. We followed flower and fruit production through observations with binoculars and photographs. Results: Each adult individual produced, on average, one leaf every 61 days. Although isolated individuals flowered throughout the year, most palms flowered synchronously at each elevation in October 2016-August 2017 and in August 2018-February 2019 and had ripe fruits 7-13 months later. Flowering started at 2 600 m, followed by 2 800 and 3 000 m. Palms at 2 400 m, the lower limit of the palm stands in the area, showed a singular behavior, with scarce flower and fruit production, some individuals that changed sex, and a higher proportion of pistillate palms. Each palm produced 1-11 (x̄ = 5.3, SD = 2.2) inflorescences and 1-10 (x̄ = 5.3, SD = 2.2) infructescences. The average number of fruits per infructescence was 4 465 (SD = 1 488). With an estimated population of adult palms between 256 000 and 600 000 and an overall ratio of pistillate: staminate individuals 1:1 or 1:2, total fruit production in the area during each fruiting period is estimated as 2.0-7.1 billion fruits. Conclusions: The huge number of flowers and fruits and their gradual availability along the altitudinal gradient have a major impact on the spatial and temporal distribution of food offer for fauna associated with the palm.

2011 ◽  
Vol 83 (3) ◽  
pp. 1007-1020 ◽  
Author(s):  
Maria Gabriela G. Camargo ◽  
Regina M. Souza ◽  
Paula Reys ◽  
Leonor P.C. Morellato

The Brazilian cerrado has undergone an intense process of fragmentation, which leads to an increase in the number of remnants exposed to edge effects and associated changes on environmental conditions that may affect the phenology of plants. This study aimed to verify whether the reproductive phenology of Xylopia aromatica (Lam.) Mart. (Annonaceae) differs under different light conditions in a cerrado sensu stricto (a woody savanna) of southeastern Brazil. We compared the reproductive phenology of X. aromatica trees distributed on east and south cardinal faces of the cerrado during monthly observations, from January 2005 to December 2008. The east face had a higher light incidence, higher temperatures and canopy openness in relation to south face. X. aromatica showed seasonal reproduction at both faces of the cerrado, but the percentage of individuals, the synchrony and duration of phenophases were higher at the east face. The study demonstrated the influence of the environmental conditions associated to the cardinal orientation of the cerrado faces on the phenological pattern of X. aromatica. Similar responses may be observed for other species, ultimately affecting patterns of floral visitation and fruit production, which reinforces the importance of considering the cardinal direction in studies of edge effects and fragmentation.


2015 ◽  
Vol 10 (3) ◽  
pp. 163 ◽  
Author(s):  
Rocco Bochicchio ◽  
Roberta Rossi ◽  
Rosanna Labella ◽  
Giovanni Bitella ◽  
Michele Perniola ◽  
...  

The demand for sources of nutraceuticals has led to the rediscovery and diffusion of traditional crops such as chia (<em>Salvia hispanica</em> L.), whose leaves and fruits are rich in W3 fatty acids and anti-oxidants. Chia originates in Central America but it is rapidly expanding to new areas. A field experiment conducted at Atella in Basilicata (Southern Italy) was set up to test the response of chia to N top-dress fertilisation (0 and 20 kg ha<sup>–1</sup>) and to sowing density (D1=125, D2=25, D3=8 and D4=4 plants m<sup>–2</sup>) in a split-plot design with three replications. First results show maximum leaf area index values up to 7.1 and fresh vegetative biomass production at early flowering ranging between 50.87 (D4) and 59.71 (D1) t ha<sup>–1</sup>. Yield increased with plant density: a significantly (P&lt;0.01) higher production (398 kg ha<sup>–1</sup>) was reached in D1. N top-dressing had a detrimental effect on yield and corresponded to higher lodging and lower maturation percentage of seeds, though non-significant. Based on our first results it seems worthwhile to continue agronomical trials for chia in herbaceous systems of southern Italy for leaf production based on traditional genotypes, while fruit production might be pursued by adopting high sowing density and the search for longer-day genotypes.


2021 ◽  
Vol 269 ◽  
pp. 01012
Author(s):  
Jiangrong Li ◽  
Qiqiang Guo ◽  
Heping Ma ◽  
Weilie Zheng

Knowledge of altitudinal patterns in soil C, N and P distribution is important for understanding biogeochemical processes in mountainous forests, yet the influence of slope aspects on soil stoichiometry has been largely neglected in previous studies. In this paper, a total number of 150 topsoil samples at four altitudes (3700, 3900, 4100, 4380 m a.s.l.) on sunny and shady slopes of Sygera mountains in the Southeastern Tibet were collected. Soil C, N and P contents, and pH, were measured. Soil temperature, moisture and richness of plant species were investigated at each sampling site. The results showed that: 1) in sunny slope, soil C, N and P concentrations increased with the increase in altitude, whereas soil C:N, C:P, and N:P decreased along the altitudinal gradient on s. Soil moisture was the main regulator of soil nutrition and stoichiometric ratios. 2) In shady slope, soil C and N contents had no significant difference along the altitudinal gradient except the higher values at low altitude, whereas soil P increased first and then decreased. Soil C:N increased with the increase in altitude, whereas C:P and N:P decreased first and then increased. Soil temperature and species richness were the main factors influencing soil nutrition and stoichiometric ratios. 3) Decoupling of soil C:N:P stoichiometry was observed in shady slope owing to changes in soil pH and temperature. 4) The rich contents of soil C and P were observed at two slopes along the altitudinal gradient, and high capacity of N supply existed at the topsoil in shady slope. These results suggested that slope aspect plays an important role in shaping the altitudinal pattern of soil C:N:P stoichiometry in mountainous forests.


2013 ◽  
Vol 23 (3) ◽  
pp. 301-305 ◽  
Author(s):  
Clinton J. Hunnicutt ◽  
Andrew W. MacRae ◽  
Vance M. Whitaker

With the reduction in the availability of methyl bromide as a soil fumigant for Florida strawberry (Fragaria ×ananassa) culture, annual broadleaf weeds are expected to become increasingly troublesome to control. Recent studies show that along with the new fumigant systems, separate but complementary herbicide applications throughout the growing season will also be a necessity for acceptable weed control. The purpose of the study reported herein was to evaluate the impacts of multiple rates of the herbicide clopyralid on the growth and fruit production of four annual strawberry cultivars. Two greenhouse trials were conducted, evaluating the application of varying rates of clopyralid as a directed spray to well-established, mature plants of ‘Strawberry Festival’, ‘Florida Radiance’, ‘Treasure’, and Winterstar™ ‘FL 05–107’. Leaf production, leaf malformation, and marketable yield were evaluated to determine negative effects because of the physiological herbicidal effects, phytotoxic herbicidal effects, or both of clopyralid. Results from these studies showed that when clopyralid was applied at the maximum labeled rate of 3 oz/acre, less than 12% leaf malformation was observed among all cultivars, and marketable yield exhibited a linear increase as the rate of clopyralid increased, possibly due to a reduction in canopy coverage leading to more effective pollination.


2021 ◽  
Author(s):  
Damie Pak ◽  
Varun Swamy ◽  
Patricia Alvarez-Loayza ◽  
Fernando Cornejo ◽  
Simon A. Queenborough ◽  
...  

Phenology has long been hypothesized as an avenue for niche partitioning or interspecific facilitation, both promoting species coexistence. Tropical plant communities exhibit striking diversity in reproductive phenology, including seasonal patterns of fruit production. Here we study whether this phenological diversity is non-random, what are the temporal scales of phenological patterns, and ecological factors that drive reproductive phenology. We applied multivariate wavelet analyses to test for phenological synchrony versus compensatory dynamics (i.e. anti-synchronous patterns where one species' decline is compensated by the rise of another) among species and across temporal scales. We used data from long-term seed rain monitoring of hyperdiverse plant communities in the western Amazon. We found significant synchronous whole-community phenology at a wide range of time scales, consistent with shared environmental responses or positive interactions among species. We also observed both compensatory and synchronous phenology within groups of species likely to share traits (confamilials) and seed dispersal mechanisms. Wind-dispersed species exhibited significant synchrony at ~6 mo scales, suggesting these species share phenological niches to match seasonality of wind. Our results indicate that community phenology is shaped by shared environmental responses but that the diversity of tropical plant phenology partly results from temporal niche partitioning. The scale-specificity and time-localized nature of community phenology patterns highlights the importance of multiple and shifting drivers of phenology.


HortScience ◽  
2006 ◽  
Vol 41 (2) ◽  
pp. 329-335 ◽  
Author(s):  
Sorkel Kadir ◽  
Edward Carey ◽  
Said Ennahli

Plant growth, yield, and fruit quality of two strawberries (Fragaria ×ananassa Duch.)—`Chandler' and `Sweet Charlie'—grown under high tunnels (HTs) were compared with that of field plants during 2002–03 and 2003–04 growing seasons. Plug plants were planted in mid-October 2002 and mid-September 2003 on raised beds covered with black polyethylene mulch. Microclimate of the HTs protected strawberry crowns from winter damage and advanced fruit production 5 weeks earlier than that of plants grown under field conditions. From December to February, average minimum and maximum crown temperatures under the HTs were 5 and 12 °C warmer than those of the field crowns, respectively. The earliest HT fruit were harvested on 7 Apr. 2003 and 11 Mar. 2004. Yield and fruit quality under the HTs were superior to that of field-grown plants. HT plants, especially `Sweet Charlie', bloomed earlier than did field plants, but `Chandler' produced higher yield than `Sweet Charlie' late in the season. Larger fruit with higher soluble solids concentration (SSC) were produced inside the HTs than outside. HT `Sweet Charlie' fruit were sweeter than `Chandler' fruit, but `Chandler' produced larger fruit. Larger leaf area, greater number of leaves and shoot biomass, more branch-crowns, and fewer runners were developed under HTs than field conditions. Total leaf area, leaf production, total shoot biomass, and number of branch-crowns of HT `Chandler' were greater than HT `Sweet Charlie'. Results of this study indicate that strawberry plants under HTs were not only precocious, but also produced higher yields and superior quality to that of field plants. HT conditions suppressed runner growth, but enhanced branch-crown development.


1992 ◽  
Vol 70 (5) ◽  
pp. 958-964 ◽  
Author(s):  
Jon Lovett Doust

The influence of plant population density on bush beans is analyzed in terms of its effect on flower, fruit, and leaf demography, biomass, and yield. Plants grown at the lowest density (solitary plants) did best in terms of leaf production, total leaf days, flowers, and production of marketable pods (i.e., having at least one seed). These plants also accumulated more biomass and had greater numbers of all components of yield. In addition, they showed greater proportionate allocation to reproduction. In all density treatments the second flower cohort (produced 33–35 days after seeds were sown) made the greatest contribution to yield (43–78%). When flower production began, the rate of leaf initiation declined; leaf mortality seemed coupled to the onset of fruit production and was most severe in plants that had many pods to mature. The probability that flowers produced under any density regime would become pods and that these pods in turn would become marketable pods was assessed. Pod production was broken down into two stages: the transition from flower to fruit and from fruit to marketable pod. The results suggest that the transition from flower to fruit is not resource-limited, but the transition from fruit to marketable pod is dependent on current resource supply. When the data are examined on a per pot basis, plants at the highest density were most productive in terms of nonproductive tissues. However, an intermediate density (equivalent to 200 plants/m2) produced the greatest total reproductive biomass and the greatest number of marketable pods per unit area. The value of leaf and flower demography as measures of uniformity of maturation, optimal planting density, and cultivar performance is discussed. Key words: density, flower demography, fruit demography, leaf demography, Phaseolus vulgaris, yield.


2008 ◽  
Vol 68 (4) ◽  
pp. 741-749 ◽  
Author(s):  
CCZ. Branco ◽  
RA. Krupek ◽  
CK. Peres

Seasonal dynamics of macroalgal communities was analyzed monthly by samplings in three stream segments of the Pedras River Basin, mid-south region of Paraná State, southern Brazil, from April 2004 to March 2005. The seasonal fluctuations in macroalgal species richness and abundance were correlated with selected environmental variables. In general, the seasonal distribution patterns of these communities were distinct from those reported from other tropical and temperate regions, with higher macroalgal richness and abundance observed from late spring to late fall. Multiple linear regression analysis revealed that the stream variable most closely related with the temporal distribution pattern observed was temperature, which had a very similar seasonal pattern to the biological parameters. On the other hand, the floristic composition was quite diverse in the streams sampled. Among the 25 taxa identified, only two were common to the three streams whereas 15 were restricted to a single sampling site. These data indicate that, although temperature seems to be an effective relationship with global temporal pattern, particular characteristics of each stream can strongly influence the seasonal tendencies in local scale. The results of Detrended Correspondence Analysis (DCA) and Cluster Analysis corroborated this observation.


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