scholarly journals High Productivity Makes Mangroves Potentially Important Players in the Tropical Silicon Cycle

2021 ◽  
Vol 8 ◽  
Author(s):  
Elani B. Elizondo ◽  
Joanna C. Carey ◽  
Alia N. Al-Haj ◽  
Ariel E. Lugo ◽  
Robinson W. Fulweiler

Over the last two decades, recognition of the important role terrestrial plants play in regulating silicon (Si) cycling has emerged. Si improves plant fitness by protecting them from abiotic (e.g., desiccation) and biotic (e.g., fungal attack) stressors. Once incorporated into plant biomass this biogenic Si is more bio-available than the lithogenic material from which it was ultimately derived. Thus plants play a key function in regulating the amount and timing of Si availability in downstream ecosystems. Recent work has highlighted the importance of salt marshes in the temperate Si cycle. However, the role of their tropical counterparts, mangroves, has largely gone unexplored. Here we report foliar concentrations of plant Si (as %Si by dry weight) for four Caribbean mangrove species: Conocarpus erectus (buttonwood), Laguncularia racemosa (white mangrove), Avicennia germinans (black mangrove), and Rhizophora mangle (red mangrove). Overall, the median Si concentration was low (0.07%) and did not vary among plant part (e.g., foliage, twig, and propagule). There was also little variation in Si among species. Using literature values of aboveground net primary production, and the concentrations reported here, we estimate an aboveground mangrove Si uptake rate of 2–10 kg Si ha–1 year–1. These rates are on par with rates reported for temperate and boreal forests as well as low nutrient salt marshes, but lower than estimates for high nutrient salt marshes. Thus, despite the low Si concentrations observed in mangroves, their high productivity appears to make them a hot spot of Si cycling in tropical coastal systems.

2020 ◽  
Author(s):  
Arne Poyda ◽  
Thorsten Reinsch ◽  
Inger J. Struck ◽  
R. Howard Skinner ◽  
Christof Kluß ◽  
...  

Abstract Aims This study aimed to investigate how efficiently assimilated carbon (C) is incorporated in plant biomass at an intensively managed old permanent grassland, how C is partitioned between shoots and roots and what are the implications for C sequestration. Methods Using the eddy covariance technique, the atmosphere-biosphere exchange of CO2 was measured for two years at a sandy grassland site in northern Germany. In addition to aboveground net primary production (ANPP), belowground NPP (BNPP) was observed using the ingrowth core method. Results The grassland showed a high productivity in terms of biomass yield (14.8 Mg dry matter ha−1 yr−1) and net CO2 uptake (−2.82 Mg CO2-C ha−1 yr−1). Photosynthetically assimilated C was converted to biomass with a high carbon use efficiency (CUE) of 71% during the growing season. However, a comparably low fraction of 17% of NPP was allocated to roots (fBNPP). Consequently, the main fraction of NPP was removed during harvest, turning the site into a net source of 0.29 Mg C ha−1 yr−1. Conclusions Our study showed the flexibility of grass root growth patterns in response to alterations in resource availability. We conclude that highly fertilized grasslands can lose their ability for C sequestration due to low belowground C allocation.


2016 ◽  
Vol 2 (91) ◽  
pp. 74-79
Author(s):  
V.H. Kurhak ◽  
M.I. Shtakal ◽  
V.M. Shtakal

There showed the productivity, chemical composition of feed and the timing of mowing of grass and variety mixes of permanent grasses on drained peat soils of Left Bank Forest-Steppe of Ukraine. The presence of early rip­ ened seeded grass provides a uniform supply use mowed mass from middle May until the end of September and the productivity of lands, which ranges from 10 to 14 t/ha of dry weight, metabolizable energy – 100.0 – 130.0 GJ and feed units 7-11 t/ha. Additional manuring of N90 on the background Р45К120 is effective at the start of second year of use. On the organization of hay conveyors of different ripening time herbages is possible to extend the optimal tim­ ing of mowing of green mass to 25-35 days. Best among the early-maturing grass crops are Dactylis glomerata va­ riety Kyivska rannia-1 with Alopecurus pratensis variety Sarnenskiy ranniy or its mixture with Bromus inermis and Festuca pratensis. With medium ripening – pure sowing eastern fescue of variety Lyudmila, Phalaris arundinacea variety Sarnenski-40, Bromus inermis variety Arsen and their compounds. High productivity of late-ripening herb­ age is provided by the inclusion in the composition of grass mixtures of Phleum pratense L. variety Vyshgorodska and Dactylis glomerata of variety Ukrainka, and Agrostis gigantea Roth variety Sarnenska piznia. It is also possible organization hay conveyors of different ripening varieties of Dactylis glomerata varieties Kyivska rannia, Muravka, Ukrainka.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 485b-485
Author(s):  
Lisa M. Barry ◽  
Michael N. Dana

Nurse crops are often recommended in prairie restoration planting. This work investigated several alternative nurse crops to determine their utility in prairie planting. Nurse crops were composed of increasing densities (900, 1800, or 2700 seeds/m2) of partridge pea, spring oats, spring barley, Canada wild rye, or equal mixtures of partridge pea and one of the grasses. The experimental design was a randomized complete-block set in two sites with three blocks per site and 48 treatments per block. Each 3 × 3-m plot contained 1 m2 planted in Dec. 1995 or Mar. 1996 with an equal mix of seven prairie species. The nurse crops were sown over each nine square meter area in April 1996. Plots lacking nurse crops served as controls. Evaluated data consisted of weed pressure rankings and weed and prairie plant dry weight. Nurse crop treatments had a significant effect on weed pressure in both sites. Barley (1800 and 2700 seeds/m2) as well as partridge pea + barley (2700 seeds/m2) were most effective at reducing weed pressure. When weed and prairie plant biomass values were compared, a significant difference was observed for site quality and planting season. Prairie plant establishment was significantly greater in the poorly drained, less-fertile site and spring-sown plots in both sites had significantly higher prairie biomass values. Overall, after two seasons, there was no advantage in using nurse crops over the control. Among nurse crop treatments, oats were most effective in reducing weed competition and enhancing prairie plant growth.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 989
Author(s):  
Basáñez-Muñoz Agustín de Jesús ◽  
Jordán-Garza Adán Guillermo ◽  
Serrano Arturo

Mangrove forests have declined worldwide and understanding the key drivers of regeneration at different perturbation levels can help manage and preserve these critical ecosystems. For example, the Ramsar site # 1602, located at the Tampamachoco lagoon, Veracruz, México, consists of a dense forest of medium-sized trees composed of three mangrove species. Due to several human activities, including the construction of a power plant around the 1990s, an area of approximately 2.3 km2 has suffered differential levels of perturbation: complete mortality, partial tree loss (divided into two sections: main and isolated patch), and apparently undisturbed sites. The number and size of trees, from seedlings to adults, were measured using transects and quadrats. With a matrix of the abundance of trees by size categories and species, an ordination (nMDS) showed three distinct groups corresponding to the degree of perturbation. Projection matrices based on the size structure of Avicennia germinans showed transition probabilities that varied according to perturbation levels. Lambda showed growing populations except on the zone that showed partial tree loss; a relatively high abundance of seedlings is not enough to ensure stable mangrove dynamics or start regeneration; and the survival of young trees and adult trees showed high sensitivity.


HortScience ◽  
2017 ◽  
Vol 52 (5) ◽  
pp. 764-769 ◽  
Author(s):  
Qiang Zhu ◽  
Monica Ozores-Hampton ◽  
Yuncong Li ◽  
Kelly Morgan ◽  
Guodong Liu ◽  
...  

Florida produces the most vegetables in the United States during the winter season with favorable weather conditions. However, vegetables grown on calcareous soils in Florida have no potassium (K) fertilizer recommendation. The objective of this study was to evaluate the effects of K rates on leaf tissue K concentration (LTKC), plant biomass, fruit yield, and postharvest quality of tomatoes (Solanum lycopersicum L.) grown on a calcareous soil. The experiment was conducted during the winter seasons of 2014 and 2015 in Homestead, FL. Potassium fertilizers were applied at rates of 0, 56, 93, 149, 186, and 223 kg·ha−1 of K and divided into preplant dry fertilizer and fertigation during the season. No deficiency of LTKC was found at 30 days after transplanting (DAT) in both years. Potassium rates lower than 149 kg·ha−1 resulted in deficient LTKC at 95 DAT in 2014. No significant responses to K rates were observed in plant (leaf, stem, and root combined) dry weight biomass at all the sampling dates in both years. However, at 95 DAT, fruit dry weight biomass increased with increasing K rates to 130 and 147 kg·ha−1, reaching a plateau thereafter indicated by the linear-plateau models in 2014 and 2015, respectively. Predicted from quadratic and linear-plateau models, K rates of 173 and 178 kg·ha−1 were considered as the optimum rates for total season marketable yields in 2014 and 2015, respectively. Postharvest qualities, including fruit firmness, pH, and total soluble solids (TSS) content, were not significantly affected by K rates in both years. Overall, K rate of 178 kg·ha−1 was sufficient to grow tomato during the winter season in calcareous soils with 78 to 82 mg·kg−1 of ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extracted K in Florida.


2019 ◽  
Vol 50 (3) ◽  
pp. 155-163 ◽  
Author(s):  
B. Talebi ◽  
M. Heidari ◽  
H. Ghorbani

Abstract The elevation of arsenic (As) content in soils is of considerable concern with respect to its uptake by plant and subsequent entry into wildlife and human food chains. The treatment of sorghum seedlings with As as NaH2As4O. 7H2O at various concentrations (A1 = 0, A2 = 20, A3 = 40 and A4 = 60 mg As kg−1 soil) and salinity at four different levels (S1 = 0, S2 = 3, S3 = 6 and S3 = 9 dS m−1) reduced fresh and dry weights of sorghum plants. The co-application of As and salinity increased the guaiacol peroxidase (GPX) activity in shoot and root tissues. The highest GPX activity in shoot and root tissues was obtained at S2A4 and S3A3 treatments, respectively. The activity of catalase (CAT) in shoot was not changed, but unlike the GPX activity, salinity and As decreased the CAT activity in root tissues. Concerning the photosynthesis pigments, salinity had no effect on the chlorophyll ‘a’, chlorophyll ‘b’ and carotenoid content in leaves, but the As treatment significantly decreased the content of both chlorophyll types. Salinity increased the anthocyanin content in leaves. There were negative correlation between soluble carbohydrates (r2 = −0.78**) and stomata conductance (r2 = −0.45**) and dry weight of the plant biomass in this study. By increasing the salinity and As concentration in root medium, soluble carbohydrate in leaves increased but salinity decreased the leaf stomata conductance.


2021 ◽  
Vol 23 (2) ◽  
pp. 121-128
Author(s):  
Advent F. Sitanggang ◽  
Marulak Simarmata ◽  
Bilman Wilman Simanihuruk ◽  
Uswatun Nurjanah

[ALLELOCHEMICAL POTENTIAL OF AQUEOUS EXTRACT AND MULCH OF PLANT BIOMASS OF SORGHUM (Sorgum bicolor L. Moench)]. This study was aimed to examine the allelopathic potential of sorghum through aqueous extract and mulch from biomass on seed germination and early growth of three tested plants, namely rice, mustard and cucumber. The results showed that the aqueous extract of the sorghum biomass significantly inhibited the germination of mustard and cucumber seeds, reduced the vigor-index of the germination of rice, mustard and cucumber seeds, and suppressed the growth of radicle length of mustard sprouts. The same thing was seen when sorghum biomass was tested as mulch which also suppressed the early growth of the tested plants on the variables of stem height, fresh and dry weight of biomass of rice, mustard and cucumber. The higher the concentration of allelochemicals extract or sorghum mulch, the stronger the inhibition on germination and early growth of the three test plants. At a concentration of 10% allelochemicals suppressed the germination of mustard and cucumber to 76 and 79%, respectively, while a dose of 10% mulch suppressed early growth in the height of rice, mustard, and cucumber to 56, 55, and 68%; and dry weight to 53, 30 and 60%. The results of this study are important information about the allelochemical potential of sorghum as a natural herbicide in integrated weed management


2006 ◽  
Vol 54 (4) ◽  
pp. 469-485 ◽  
Author(s):  
G. Singh ◽  
D. Wright

Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (Pisum sativum) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as Polygonum aviculare, Poa annua and Elymus repens. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 917
Author(s):  
Domenico Ronga ◽  
Aldo Dal Prà ◽  
Alessandra Immovilli ◽  
Fabrizio Ruozzi ◽  
Roberto Davolio ◽  
...  

The aim of this work was to study the yield and nutritional characteristics of winter wheat hay. A selection of cultivars recommended for three main purposes: grain, whole plant (biomass) and dual purpose (grain and biomass) production were cultivated and harvested from heading to grain dough stages. Yield dry weight (YDW), dry matter (DM) and undigested neutral detergent fiber (uNDF) increased with advancing maturity, ranging from 9 t ha−1, 20 and 11% of DM to 16 t ha−1, 43 and 17% of DM, respectively; while crude protein (CP) and neutral detergent fiber (NDF) decreased from 11 and 59% of DM to 6 and 54% of DM, respectively. Our study showed that dual purpose winter wheat cultivars displayed similar performance of CP, NDF and net energy for lactation, when harvested at heading or grain milk stages. In addition, winter wheat recommended to be harvested as whole plant showed similar values of YDW, sugar and starch contents, when harvested at grain dough and milk stages. These characteristics are strategic in hay production, allowing a more flexible harvesting strategy. These results might be useful to improve the hay production, given useful information on harvest time and improving agricultural sustainability covering the soil in autumn and winter.


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