The effect of water supply on tree seed germination and seedling survival in a tropical seasonal forest in Veracruz, Mexico

1991 ◽  
Vol 7 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Dominique Blain ◽  
Martin Kellman
Keyword(s):  
Water Supply ◽  
Tree Species ◽  
Seedling Survival ◽  
Light Level ◽  
Water Retention Capacity ◽  
Wet Season ◽  
Retention Capacity ◽  
Large Fluctuations ◽  
Rainfall Patterns ◽  
Tropical Seasonal Forest

ABSTRACTIn Iropical seasonal forests, mass seedling death may incidentally occur early in the rainy season following untimely germination provoked by an isolated heavy rainfall. We hypothesized that, in a soil with little moisture retention capacity, irregular rainfall patterns would result in large fluctuations of water supply and, in the early wet season, drought episodes could cause seedling death. This hypothesis was tested in a seasonal tropical forest in Mexico where seedling density is low and the soil consists of almost pure sand with a low water retention capacity. Various patterns of simulated rainfall were applied in the forest to seeds and seedlings of three common tree species. Overall very little difference in germination and seedling survival was observed between the various rainfall treatments. The results showed that rainfall patterns and the soil texture may interact in a much more complex way than was initially hypothesized, and that water availability to seeds and seedlings is not necessarily predictable. The absence of seedlings of the three tree species might be better explained by high seed predation and low light level in the understorey.

scholarly journals Ecological valence of expanding European ash (Fraxinus excelsior L.) in the Bohemian Karst (Czech Republic)

2012 ◽  
Vol 52 (No. 7) ◽  
pp. 293-305 ◽  
Author(s):  
S. Střeštík ◽  
P. Šamonil
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Natural Regeneration ◽  
Average Density ◽  
Fraxinus Excelsior ◽  
Water Retention Capacity ◽  
Average Height ◽  
Retention Capacity ◽  
Tree Species Composition ◽  
Bohemian Karst

In 2002 a study focused on the evaluation of height and density of expanding natural regeneration of Fraxinus excelsior L. (FE) was carried out on Velk&aacute; hora Hill, a locality in the Bohemian Karst (Česk&yacute; kras). The examined area is located in Karl&scaron;tejn National Nature Reserve and takes up around 31 ha. The parent rock is limestone. The expansion depends on soil and exposition conditions and relates to the water balance gradient. FE reached the highest densities (up to 6,000 individuals/400 m<sup>2</sup>) on Velk&aacute; hora&rsquo;s peak plateau on medium-deep, heavy-textured decarbonized <br />soils. The lowest expansion (508 individuals/400 m<sup>2</sup>) was found on slopes fully exposed to south (S) with water retention capacity lower than 20 mm. In total, the average density was 1,190 individuals/400 m<sup>2</sup>. FE natural regeneration reached the highest average heights (around 210 cm) on Fageto-Quercetum illimerosum mesotrophicum, the smallest heights on Carpineto-Aceretum saxatile. Average height in the locality was 47 cm. No relation was found between FE natural regeneration height or density and the distance of a fertile specimen. The distance exceeded 70 m only in 3.4%. FE seeds could be detected almost everywhere at the area. FE is capable to establish itself on any location of the studied locality except ecologically extreme parts of rock steppe without forest and Fagus sylvatica L. stands occupying S slopes. On less favourable sites it is capable to use the protection of other tree species and as a low growing tree it can eventually dominate the site. In more favourable conditions it expands on the whole area, where it can dominate the undergrowth already at 1-m height. If the forest sites are left to natural development, a distinctive change in the tree species composition could take place in a short time period. Such a change could have an essential impact on light conditions, energy flux and species composition of plant and animal communities.

scholarly journals Factors limiting seed germination of terrestrial bromeliads in the sandy coastal plains (restinga) of Maricá, Rio de Janeiro, Brazil

Rodriguésia ◽  
2008 ◽  
Vol 59 (1) ◽  
pp. 135-150 ◽  
Author(s):  
André Mantovani ◽  
Ricardo Rios Iglesias
Keyword(s):  
Seed Germination ◽  
High Temperatures ◽  
Seedling Survival ◽  
Temporal Distribution ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Sand Burial ◽  
Water Potentials

ABSTRACT Vegetation islands surrounded by bare sand are one of the most characteristic features of the sandy plains (restinga) of the Brazilian coastline. Abiotic conditions outside the islands are too harsh for the establishment of plants. Bromeliads are frequent both inside and at the borders of islands, but infrequent outside the islands in the restinga of Maricá. We hypothesized that the rarity of bromeliad seedlings in the restinga is due to high mortality during the seed and/or seedling stages. In this study, we assessed the potential limiting factors for germination and seedling survival of three terrestrial bromeliads Neoregelia cruenta, Aechmea nudicaulis and Vriesea neoglutinosa. Seed viability, water balance during dry-wet cycles, germination under different water potentials and the susceptibility of seedlings to high temperatures, desiccation and sand burial were analyzed. The tested seeds were nondormant, and they germinated to >70% even after exposure to 60ºC and desiccation. At temperatures > 27ºC, seeds lost water faster than imbibited it, and drywet cycles and water potentials of -0.4 MPa decreased germination. Thus, low water availability is likely limiting factor for bromeliad seed germination in the restinga of Maricá. Seedlings were extremely sensitive to high temperatures and sand burial. Shoots failed to emerge if seed depth exceeded 10 mm. We suggest that unequal temporal distribution of rainfall, low water retention capacity of the soil, and high temperatures inhibit germination and seedling establishment through water stress. Consequently, bromeliads are not likely to act as pioneer plants in the barren regions that separate restinga islands.

Evaluation of Resistant Starch Quality from Different Types of Banana in Batter Coating Formulation to Reduce Oil Absorption in Fried Food

2019 ◽  
Vol 2 (2) ◽  
pp. 115-120
Author(s):  
Karissha Fritzi Della ◽  
Mutiara Pratiwi ◽  
Purwa Tri Cahyana ◽  
Maria DPT Gunawan-Puteri
Keyword(s):  
Resistant Starch ◽  
Extraction Process ◽  
Fat Content ◽  
Water Retention Capacity ◽  
Oil Absorption ◽  
Retention Capacity ◽  
Fried Food ◽  
Musa Paradisiaca ◽  
Different Types ◽  
Coating Formulation

Fried food is convenient for many people due to its pleasant texture and taste. On the other hand, it comes with the risk of high oil absorption which might lead to certain health problems. Resistant starch (RS) has been known to have a functionality of reducing oil absorption. Three different types of banana: Kepok (Musa paradisiaca formatypica), Raja Bulu (Musa paradisiaca L.) and Ambon (Musa paradisiaca L. var sapientum) were evaluated on its performance when utilized as source of resistant starch especially on their application in reducing oil absorption in fried food. Tempeh was used as the food model. Banana starch (RS2) was isolated through water alkaline extraction process, continued with modification process through three repeated cycles of autoclaving-cooling process to obtain the RS3. RS3 was added into the batter coating formulation at three substitution ratios (10%, 30% and 50%) and then used to coat tempeh before frying. Evaluation of resistant starch in batter and battered productwas conducted on the following parameters: fat content, water retention capacity (WRC), coating pick up and sensory analysis. The result of this study revealed that Raja Bulu showed the most effective result on reducing oil absorption in the food tested. In the three bananas used, the ratio of 50% performed best in coating pick up (highest), WRC (highest) and fat content(lowest) parameters, but not significantly different with the 30% ratio. In terms of sensory acceptance, using Raja Bulu as the selected banana type, 30% of substitution ratio was significantly more preferable by the panelists in crispness, oiliness, and overall acceptance attributes compared to control and other substitution ratios.

scholarly journals Kombucha Tea as a Reservoir of Cellulose Producing Bacteria: Assessing Diversity among Komagataeibacter Isolates

2021 ◽  
Vol 11 (4) ◽  
pp. 1595
Author(s):  
Salvatore La China ◽  
Luciana De Vero ◽  
Kavitha Anguluri ◽  
Marcello Brugnoli ◽  
Dhouha Mamlouk ◽  
...  
Keyword(s):  
Intraspecific Diversity ◽  
Water Retention Capacity ◽  
Combined Model ◽  
Discrimination Power ◽  
Retention Capacity ◽  
High Mechanical Strength ◽  
Kombucha Tea ◽  
Typing Methods ◽  
Fermented Beverage ◽  
Tea Production

Bacterial cellulose (BC) is receiving a great deal of attention due to its unique properties such as high purity, water retention capacity, high mechanical strength, and biocompatibility. However, the production of BC has been limited because of the associated high costs and low productivity. In light of this, the isolation of new BC producing bacteria and the selection of highly productive strains has become a prominent issue. Kombucha tea is a fermented beverage in which the bacteria fraction of the microbial community is composed mostly of strains belonging to the genus Komagataeibacter. In this study, Kombucha tea production trials were performed starting from a previous batch, and bacterial isolation was conducted along cultivation time. From the whole microbial pool, 46 isolates were tested for their ability to produce BC. The obtained BC yield ranged from 0.59 g/L, for the isolate K2G36, to 23 g/L for K2G30—which used as the reference strain. The genetic intraspecific diversity of the 46 isolates was investigated using two repetitive-sequence-based PCR typing methods: the enterobacterial repetitive intergenic consensus (ERIC) elements and the (GTG)5 sequences, respectively. The results obtained using the two different approaches revealed the suitability of the fingerprint techniques, showing a discrimination power, calculated as the D index, of 0.94 for (GTG)5 rep-PCR and 0.95 for ERIC rep-PCR. In order to improve the sensitivity of the applied method, a combined model for the two genotyping experiments was performed, allowing for the ability to discriminate among strains.

scholarly journals Buoyancy control in ammonoid cephalopods refined by complex internal shell architecture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David J. Peterman ◽  
Kathleen A. Ritterbush ◽  
Charles N. Ciampaglio ◽  
Erynn H. Johnson ◽  
Shinya Inoue ◽  
...  
Keyword(s):  
Surface Tension ◽  
Water Retention Capacity ◽  
Functional Explanation ◽  
Retention Capacity ◽  
Biomechanical Stress ◽  
Liquid Retention ◽  
3D Printed ◽  
Functional Explanations ◽  
Hydrophilic Coatings ◽  
The Impact

AbstractThe internal architecture of chambered ammonoid conchs profoundly increased in complexity through geologic time, but the adaptive value of these structures is disputed. Specifically, these cephalopods developed fractal-like folds along the edges of their internal divider walls (septa). Traditionally, functional explanations for septal complexity have largely focused on biomechanical stress resistance. However, the impact of these structures on buoyancy manipulation deserves fresh scrutiny. We propose increased septal complexity conveyed comparable shifts in fluid retention capacity within each chamber. We test this interpretation by measuring the liquid retained by septa, and within entire chambers, in several 3D-printed cephalopod shell archetypes, treated with (and without) biomimetic hydrophilic coatings. Results show that surface tension regulates water retention capacity in the chambers, which positively scales with septal complexity and membrane capillarity, and negatively scales with size. A greater capacity for liquid retention in ammonoids may have improved buoyancy regulation, or compensated for mass changes during life. Increased liquid retention in our experiments demonstrate an increase in areas of greater surface tension potential, supporting improved chamber refilling. These findings support interpretations that ammonoids with complex sutures may have had more active buoyancy regulation compared to other groups of ectocochleate cephalopods. Overall, the relationship between septal complexity and liquid retention capacity through surface tension presents a robust yet simple functional explanation for the mechanisms driving this global biotic pattern.

scholarly journals Fire suppression and seed dispersal play critical roles in the establishment of tropical forest tree species in southeastern Africa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomohiro Fujita
Keyword(s):  
Seed Dispersal ◽  
Tree Species ◽  
Seedling Survival ◽  
Fire Suppression ◽  
Forest Tree ◽  
Tree Seedlings ◽  
Seedling Mortality ◽  
Forest Tree Species ◽  
Seed Deposition ◽  
Syzygium Guineense

AbstractThis study examined the mechanisms of facilitation and importance of seed dispersal during establishment of forest tree species in an Afrotropical woodland. Seedling survival of Syzygium guineense ssp. afromontanum was monitored for 2.5 years at four different microsites in savannah woodland in Malawi (southeastern Africa) under Ficus natalensis (a potential nurse plant), Brachystegia floribunda (a woodland tree), Uapaca kirkiana (a woodland tree), and at a treeless site. The number of naturally established forest tree seedlings in the woodland was also counted. Additionally, S. guineense ssp. afromontanum seed deposition was monitored at the four microsites. Insect damage (9% of the total cause of mortality) and trampling by ungulates (1%) had limited impact on seedling survival in this area. Fire (43%) was found to be the most important cause of seedling mortality and fire induced mortality was especially high under U. kirkiana (74%) and at treeless site (51%). The rate was comparatively low under F. natalensis (4%) and B. floribunda (23%), where fire is thought to be inhibited due to the lack of light-demanding C4 grasses. Consequently, seedling survival under F. natalensis and B. floribunda was higher compared with the other two microsites. The seedling survival rate was similar under F. natalensis (57%) and B. floribunda (59%). However, only a few S. guineense ssp. afromontanum seedlings naturally established under B. floribunda (25/285) whereas many seedlings established under F. natalensis (146/285). These findings indicate that the facilitative mechanism of fire suppression is not the only factor affecting establishment. The seed deposition investigation revealed that most of the seeds (85%) were deposited under F. natalensis. As such, these findings suggest that in addition to fire suppression, dispersal limitations also play a role in forest-savannah dynamics in this region, especially at the community level.

scholarly journals Chemical Composition and Functional Properties of Dietary Fibre Concentrates from Winemaking By-Products: Skins, Stems and Lees

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1510
Author(s):  
María Ángeles Rivas ◽  
Rocío Casquete ◽  
María de Guía Córdoba ◽  
Santiago Ruíz-Moyano ◽  
María José Benito ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Functional Properties ◽  
Dietary Fibre ◽  
Water Retention ◽  
Point Of View ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Oil Retention ◽  
High Antioxidant Activity ◽  
By Products

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.

Host preferences of low-trunk vascular epiphytes in a cloud forest of Veracruz, Mexico

2005 ◽  
Vol 21 (6) ◽  
pp. 651-660 ◽  
Author(s):  
Klaus Mehltreter ◽  
Alejandro Flores-Palacios ◽  
José G. García-Franco
Keyword(s):  
Water Retention ◽  
Cloud Forest ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Host Preferences ◽  
Host Group ◽  
Vascular Epiphytes ◽  
Lower Trunk ◽  
Tree Ferns ◽  
Epiphyte Species

The diversity, abundance and frequency of vascular epiphytes on the lower trunk were compared between two host groups of a Mexican cloud forest: angiosperm trees (n = 72) and tree ferns (n = 28). The bark of the five most frequent host trees and the root mantle of the two tree ferns were analysed for their thickness, water content, water retention capacity and pH. A total of 55 epiphyte species and 910 individuals were found on the 27 host species. On hosts with a dbh range of 5–10 cm, epiphytes were significantly more diverse (4.3±0.9 species per host) and more abundant (12.5±2.2 individuals per host) on tree ferns than on angiosperm trees (1.9±0.2 species per host and 3.9±0.6 individuals per host). However, these differences were not significant for the dbh class of 10–20 cm, because epiphyte numbers increased on angiosperm trees with larger host size, but not in tree ferns. Most epiphyte species had no preference for any host group, but four species were significantly more frequent on tree ferns and two species on angiosperm trees. The higher epiphyte diversity and abundance on tree fern trunks of the smallest dbh class is attributed to their presumably greater age and to two stem characteristics, which differed significantly between host groups, the thicker root mantle and higher water retention capacity of tree ferns. These bark characteristics may favour germination and establishment of epiphytes.

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