scholarly journals Germination characteristics of Salicornia patula Duval-Jouve, S. emerici Duval-Jouve, and S. veneta Pign. et Lausi and their occurrence in Croatia

2013 ◽  
Vol 72 (2) ◽  
pp. 347-358 ◽  
Author(s):  
Nina Šajna ◽  
Marjana Regvar ◽  
Simona Kaligarič ◽  
Željko Škvorc ◽  
Mitja Kaligarič
Keyword(s):  
Environmental Factors ◽  
Habitat Preferences ◽  
Seed Morphology ◽  
Salicornia Europaea ◽  
Molecular Analyses ◽  
High Germination ◽  
Germination Characteristics ◽  
Salicornia Patula ◽  
Floral Characters

Abstract - According to recent molecular analyses of Salicornia, we revised the annual glassworts from the Croatian coast, classified until now only as Salicornia europaea. Two species, a diploid Salicornia patula and a tetraploid S. emerici were recognized. They can be easily distinguished by floral characters, but not only by their habitus, which varies extremely according to environmental factors. Both species differ also in seed morphology. Salicornia patula has dimorphic seeds, with larger central seeds reaching high germination rates. Germination patterns helped to explain the habitat preferences. The species rarely co-occur, however. The rare S. patula occupies drier habitats, on coastal mudflats or sands that are irregularly inundated. It occurs within the assoc. Suaedo maritimae-Salicornietum patulae. Salicornia emerici occupies the lowest coastal mudflats, regularly inundated, where nutrient-rich conditions prevail, and forms an almost monotypical assoc. Salicornietum emerici. Due to the synonymy of S. veneta with S. emerici, we exclude the occurrence of S. veneta in Croatia as an independent taxon.

Effects of light, temperature and population variability on the germination of seven Spanish pines

2002 ◽  
Vol 12 (4) ◽  
pp. 261-271 ◽  
Author(s):  
A. Escudero ◽  
F. Pérez-García ◽  
A. L. Luzuriaga
Keyword(s):  
Habitat Preferences ◽  
Population Variability ◽  
Nested Models ◽  
Germination Response ◽  
Germination Characteristics ◽  
Different Populations ◽  
Effects Of Temperature ◽  
Germination Traits ◽  
The Relationship ◽  
Pine Species

AbstractMost Pinus species are obligate seeders. Thus, knowledge of germination characteristics can help in the understanding, prediction and manipulation of the regeneration and dynamics of pine forests. Seven pine species with contrasting habitat preferences and different genetic pairwise distances are present in the Iberian Peninsula and the Canary Islands: P. halepensis, P. nigra, P. pinaster, P. pinea, P. sylvestris, P. uncinata and P. canariensis. These seven pine species comprise an exceptional experimental set to test some questions related to germination traits, such as: (1) What are the effects of light and temperature on germination, taking into account interpopulation variability? (2) Is there any association of germination traits with habitat (montane versus lowland) preferences? and (3) What is the relationship between germination traits and the genetic distance between pine species? P. nigra, P. sylvestris and P. uncinata seeds showed faster germination rates. Seeds of P. nigra and P. sylvestris reached high total germination percentages in every temperature and light treatment, suggesting an opportunistic germination strategy. Unlike montane pines, lowland pines did show significant effects of temperature on germination response: final germination was higher between 15°C and 20°C than at warmer and alternating temperatures. Relatively low temperatures associated with the winter rainy season would favour germination of most of these species. Nested models showed that population variability was the main source of variation in germination response. Thus, there is no phylogenetic control of the germination response and, surprisingly, germination traits were not related to habitat preferences. As a consequence, we believe that studies of the germination characteristics of a pine species should consider different populations.

Variation of fruiting and germination characteristics of Rhododendron aganniphum var. schiaopeplum with environmental factors

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
杨紫玲，喻舞阳，郑维列，罗建，王国严，卢杰，李江荣 YANG Ziling
Keyword(s):  
Environmental Factors ◽  
Germination Characteristics

Diversity, spatiotemporal distribution, abundance, species composition and habitat preferences of Ostracoda in Akbük and Akdeniz coastal mesosaline lagoons (Muğla, the South Aegean Region, Turkey)

2015 ◽  
Vol 44 (2) ◽  
Author(s):  
Selçuk Altınsaçlı ◽  
Ferda Perçin-Paçal ◽  
Songül Altınsaçlı
Keyword(s):  
Environmental Factors ◽  
Environmental Variables ◽  
Habitat Preferences ◽  
Aegean Region ◽  
Qualitative And Quantitative ◽  
Ordination Techniques ◽  
Ecological Importance ◽  
The Relationship ◽  
Ostracod Species

AbstractAkdeniz and Akbuk lagoons are part of a shallow coastal ecosystem of great aesthetic and ecological importance, located in Muğla Province in the southern Aegean region of Turkey. In the present study, four expeditions to collect ostracods from these lagoons were conducted in May, July, October, and November of 2008. Benthic samples were obtained monthly and several environmental factors were recorded simultaneously in situ. The ecological preferences of the ostracods were monitored, and qualitative and quantitative samples were collected from three sites in Akdeniz lagoon and two sites in Akbuk lagoon. Three ostracod taxa (Cyprideis torosa, Loxoconcha elliptica and Cytherois fischeri) were identified from the Akdeniz lagoon sampling sites and one species (Cyprideis torosa) from the Akbuk lagoon sampling sites. We present and analyze the dominance and distribution of ostracod assemblages and their relationships to environmental factors: temperature, dissolved oxygen, percentage oxygen saturation, pH, redox potential, salinity, and electrical conductivity) using classification and ordination techniques. Canonical correspondence analysis (CCA) is used to characterize the relationship between ostracods and the environmental variables. Approximately 82% of the correlation between the community composition and environmental variables was explained by the first axis of the CCA ordination for the Akdeniz lagoon. The study revealed that the distribution and population density of ostracod species depends on the physicochemical properties of the environment. The reason for this is that Cyprideis torosa and Loxoconcha elliptica are euryhaline species.

scholarly journals Phytoindication approach to assessing factors determining the habitat preferences of red deer (Cervus elaphus)

2021 ◽  
Vol 29 (3) ◽  
pp. 195-206
Author(s):  
V. I. Domnich ◽  
A. V. Domnich ◽  
O. V. Zhukov
Keyword(s):  
Environmental Factors ◽  
Plant Species ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Habitat Preferences ◽  
Distribution Model ◽  
Individual Plant ◽  
Fecal Pellets ◽  
Vegetation Class ◽  
Nutrients Availability

The study examined the possibility of using the phytoindication technique to describe habitat preferences of red deer in a relatively homogeneous area. Two alternative hypotheses were tested. Hypothesis 1 suggests that the relationship between red deer and vegetation is due to a trophic factor, so preferences for individual plant species cause vegetation to influence the distribution of animal numbers. Hypothesis 2 suggests that environmental factors influence vegetation, structuring and determining the productive level of the community as a whole. Therefore, environmental factors, rather than individual plant species, cause vegetation-animal interactions. The research was conducted on Biryuchiy Island Spit, where the Azov-Sivash National Nature Park is located. The geobotanical surveys were performed in three types of ecosystems: sandy steppe (vegetation class Festucetea vaginatae), saline meadows (vegetation class Festuco–Puccinellietea), and artificial forest plantation (vegetation class Robinietea). 250 releves were recorded according to the Brown-Blanquet approach. The number of fecal pellets and the number of groups of pellets of red deer was recorded together with geobotanical surveys in the same sample plots. The pellet groups counted in the field were converted to deer densities in specific vegetation classes taking into account the number of pellet groups on the site and the decay rate of the fecal pellets. The vegetation types were distinguished by the number of deer fecal pellets per unit area. The highest number of fecal pellets was found for the plant class Festucetea vaginatae, somewhat fewer fecal pellets were in the plant class Robinietea, and the lowest number was in the plant class Festuco-Puccinellietea. A geometric distribution model is adequate for explaining the experimental data on the number of fecal pellets. A total of 59 species of flowering plants were found. Based on the species composition and projective cover of species, the ecological regimes of ecotopes were identified by phytoindication. The correspondence analysis of the vegetation revealed two ordination axes. The ordination axis 1 (CA1) was able to explain 11.3% of community inertia, and the ordination axis 2 (CA2) was able to explain 5.2% of community inertia. The maximum excretory activity of animals was recorded for the central part of the ordination space, indicating the presence of an optimum zone in the gradient of environmental factors that structure plant communities. The forward selection procedure allowed the Nutrients Availability variable to be selected as the most important variable to explain variation in the plant community structure. The number of deer fecal pellets exhibited different patterns of response in the Nutrients Availability gradient. The response within the plant class Festucetea vaginatae could best be explained by Model III from the list of HOF-models. The response of the excretory activity of deer within the class Festuco-Puccinellietea could best be fitted by the model IV, which represents a symmetric Gaussian curve. The response of excretory activity in the Robinietea vegetation class was asymmetrical bimodal. The ecological properties of the red deer ecological niche in both the drier and less mineralized part of the range of ecological conditions and the wetter and more mineralized part should be assessed in the context of the prospects for future studies.

scholarly journals Woodland Ponds as an Important Habitat of Hippeutis Complanatus (Linnaeus 1758) Occurrence - Effect of Environmental Factors and Habitat Preferences

2014 ◽  
Vol 33 (2) ◽  
Author(s):  
Aneta Spyra
Keyword(s):  
Organic Matter ◽  
Environmental Factors ◽  
Bottom Sediments ◽  
Habitat Preferences ◽  
Organic Matter Content ◽  
Matter Content ◽  
Freshwater Snails ◽  
Fallen Leaves ◽  
Woodland Ponds ◽  
Important Habitat

AbstractSpyra A. Woodland ponds as an important habitat of Hippeutis complanatus (Linnaeus 1758) occurrence - effect of environmental factors and habitat preferences. Ekológia (Bratislava), Vol. 33, No. 2, p. 101-115, 2014.In industrial areas, woodland ponds are refuges of biological diversity. The impact of environmental factors such as the physico-chemical properties of water, organic matter content in bottom sediments and various types of substratum on the occurrence of Hippeutis complanatus were assessed. In Poland, it is considered to be a species with an established but unspecified risk, deserving the status of endangered species due to the decline of wetland environments. A Canonical Correspondence Analysis (CCA) revealed associations between the distribution patterns of freshwater snails species and the concentration of nitrates (NO3) and calcium (Ca) as well as pH and the organic matter content in the bottom sediments. Based on statistical relationships, results of study suggest that the kind of substratum (Typha latifolia remains, Phragmites australis remains, fallen leaves of waterside trees) has an impact on the occurrence of freshwater snails including Hippeutis complanatus for which the preferred substratum is the fallen leaves of waterside trees and sites with a high content of organic matter in bottom sediments. The study has shown that isolated water bodies located in forest complexes can be refuges for species that occur in small numbers in other types of aquatic environments.

Landsat-derived environmental factors to describe habitat preferences and spatiotemporal distribution of phytoplankton

2019 ◽  
Vol 408 ◽  
pp. 108759
Author(s):  
Miguel Ángel Matus-Hernández ◽  
Raúl Octavio Martínez-Rincón ◽  
Rosa Judith Aviña-Hernández ◽  
Norma Yolanda Hernández-Saavedra
Keyword(s):  
Environmental Factors ◽  
Habitat Preferences ◽  
Spatiotemporal Distribution

scholarly journals Differential Responses of Dimorphic Seeds and Seedlings to Abiotic Stresses in the Halophyte Suaeda salsa

2021 ◽  
Vol 12 ◽  
Author(s):  
Hao Zhang ◽  
Mingfang Hu ◽  
Hongyuan Ma ◽  
Li Jiang ◽  
Zhenyong Zhao ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Abiotic Stresses ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Suaeda Salsa ◽  
High Germination ◽  
Germination Characteristics ◽  
Black Seeds ◽  
Germination Traits

The period between seed germination and seedling establishment is one of the most vulnerable stages in the life cycle of annuals in the saline environments. Although germination characteristics of Suaeda salsa seeds have been reported, the comparative germination patterns of dimorphic seeds and seedling growth to different abiotic stresses remain poorly understood. In this study, germination responses of dimorphic seeds to light and temperature were compared. Meanwhile, responses of dimorphic seeds and thereafter seedlings of S. salsa to different concentrations of NaCl and Na2SO4 were also tested. The results showed that the light did not significantly affect germination percentage of brown seeds, but significantly promoted germination of black seeds. Brown seeds could reach high germination percentage over a wide temperature range, however, germination of black seeds gradually increased with the increase of temperature. Brown seeds had higher germination percentage and velocity than black seeds under the same salt conditions. However, black seeds had higher recovery germination than brown seeds when transferred to deionized water. Young seedlings had lower salt tolerance than germinating seeds. At the same concentrations, Na2SO4 had stronger inhibitory effect on seed germination and seedling growth than NaCl. This study comprehensively compared germination traits of dimorphic seeds and seedling growth of S. salsa, and then developed a conceptual model to explain their adaptation to harsh saline environment.

scholarly journals Epiphyte type and sampling height impact mesofauna communities in Douglas-fir trees

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5699 ◽  
Author(s):  
Alexander R. Young ◽  
Jesse E.D. Miller ◽  
John Villella ◽  
Greg Carey ◽  
William R. Miller
Keyword(s):  
Environmental Factors ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Fine Scale ◽  
Environmental Preferences ◽  
Sampling Height ◽  
Microenvironmental Factors ◽  
Fruticose Lichen ◽  
Wet Forests ◽  
Foliose Lichen

Branches and boles of trees in wet forests are often carpeted with lichens and bryophytes capable of providing periodically saturated habitat suitable for microfauna, animals that include tardigrades, rotifers, nematodes, mites, and springtails. Although resident microfauna likely exhibit habitat preferences structured by fine-scale environmental factors, previous studies rarely report associations between microfaunal communities and habitat type (e.g., communities that develop in lichens vs. bryophytes). Microfaunal communities were examined across three types of epiphyte and three sampling heights to capture gradients of microenvironment. Tardigrades, rotifers, and nematodes were significantly more abundant in bryophytes than fruticose lichen or foliose lichen. Eight tardigrade species and four tardigrade taxa were found, representing two classes, three orders, six families, and eight genera. Tardigrade community composition was significantly different between bryophytes, foliose lichen, fruticose lichen, and sampling heights. We show that microenvironmental factors including epiphyte type and sampling height shape microfaunal communities and may mirror the environmental preferences of their epiphyte hosts.

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