scholarly journals Editorial: On the International Geoscience Program (IGCP) Project 575 – Pennsylvanian Terrestrial Habitats and Biotas of Southeastern Euramerica

2012 ◽  
Vol 65 (3) ◽  
pp. 271-272 ◽  
Author(s):  
Jasenka Sremac ◽  
Christopher J. Cleal ◽  
Mladen Juračić
Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 353
Author(s):  
Rassim Khelifa ◽  
Hayat Mahdjoub ◽  
Affef Baaloudj ◽  
Robert A. Cannings ◽  
Michael J. Samways

Agriculture can be pervasive in its effect on wild nature, affecting various types of natural habitats, including lotic ecosystems. Here, we assess the extent of agricultural expansion on lotic systems in Northern Africa (Algeria, Tunisia, and Morocco) and document its overlap with the distribution of an endemic damselfly, Platycnemis subdilatata Selys, using species distribution modeling. We found that agricultural land cover increased by 321% in the region between 1992 and 2005, and, in particular, the main watercourses experienced an increase in agricultural land cover from 21.4% in 1992 to 78.1% in 2005, together with an increase in the intensity of 226% in agricultural practices. We used capture–mark–recapture (CMR) surveys in terrestrial habitats surrounding a stream bordered by grassland and cropland in northeastern Algeria to determine demographic parameters and population size, as well as cropland occupancy. CMR modeling showed that the recapture and survival probabilities had an average of 0.14 (95%CI: 0.14–0.17) and 0.86 (0.85–0.87), respectively. We estimated a relatively large population of P. subdilatata (~1750 individuals) in terrestrial habitats. The occupancy of terrestrial habitats by adults was spatially structured by age. Our data suggest that P. subdilatata has survived agricultural expansion and intensification better than other local odonate species, mainly because it can occupy transformed landscapes, such as croplands and grasslands.


PROTOPLASMA ◽  
2021 ◽  
Author(s):  
Cynthia Medwed ◽  
Andreas Holzinger ◽  
Stefanie Hofer ◽  
Anja Hartmann ◽  
Dirk Michalik ◽  
...  

AbstractSingle-celled green algae within the Trebouxiophyceae (Chlorophyta) are typical components of terrestrial habitats, which often exhibit harsh environmental conditions for these microorganisms. This study provides a detailed overview of the ecophysiological, biochemical, and ultrastructural traits of an alga living on tree bark. The alga was isolated from a cypress tree in the Botanical Garden of Innsbruck (Austria) and identified by morphology and molecular phylogeny as Diplosphaera chodatii. Transmission electron microscopy after high-pressure freezing (HPF) showed an excellent preservation of the ultrastructure. The cell wall was bilayered with a smooth inner layer and an outer layer of polysaccharides with a fuzzy hair-like appearance that could possibly act as cell-cell adhesion mechanism and hence as a structural precursor supporting biofilm formation together with the mucilage observed occasionally. The photosynthetic-irradiance curves of D. chodatii indicated low light requirements without photoinhibition at high photon flux densities (1580 μmol photons m−2 s−1) supported by growth rate measurements. D. chodatii showed a high desiccation tolerance, as 85% of its initial value was recovered after controlled desiccation at a relative humidity of ~10%. The alga contained the low molecular weight carbohydrates sucrose and sorbitol, which probably act as protective compounds against desiccation. In addition, a new but chemically not elucidated mycosporine-like amino acid was detected with a molecular mass of 332 g mol−1 and an absorption maximum of 324 nm. The presented data provide various traits which contribute to a better understanding of the adaptive mechanisms of D. chodatii to terrestrial habitats.


2021 ◽  
Vol 13 (13) ◽  
pp. 7010
Author(s):  
Lorenzo Franchi ◽  
Thierry Vanelslander

For centuries, ports have functioned as an economic engine, facilitating maritime transport, offering prosperity and social development to the host communities. Ports are gateways for international trade playing a vital role in the world economy, but it is not excluded that port operations can also have adverse effects on the environment. Air and water emissions, marine sediments, noise, waste generation, loss and degradation of terrestrial habitats and changes to marine ecosystems are just some of the leading environmental challenges with port’s operations. Environmental management within port operations has been a rapidly growing trend, with many ports around the world adopting different types of approaches and initiatives to improve ecological performance. Despite that many ports around the world have implemented greening strategies for growth and sustainable development, there are still many other ports that work less than they should do on environmental aspects and on the generation of ‘green ports’. These latter have fallen behind in the development of the theme. Therefore, the work reported here aims at analyzing what the best way to act should be, even starting from the beginning for a port that is not very innovative, in order to pursue the practical and theoretical levels of ‘green port’.


1990 ◽  
Vol 3 ◽  
pp. 214-256 ◽  
Author(s):  
Conrad C. Labandeira ◽  
Bret S. Beall

Since the late Paleozoic, insects and arachnids have diversified in the terrestrial world so spectacularly that they have become unquestionably the most diverse group of organisms to ever inhabit the planet. In fact, this 300 million year interval may appropriately be referred to as the age of arthropods. What is the origin and history of terrestrial arthropods? How is arthropod diversity maintained on land? In this rhetorical context we will discuss (1) the degree to which terrestriality is found in arthropods, (2) the physiological barriers to terrestrialization that arthropod clades confronted, (3) the historical record of arthropod diversity on land based on paleobiological, comparative physiological and zoogeographical evidence, and (4) some tentative answers to the “why” of terrestrial arthropod success. We are providing a geochronologic scope to terrestriality that includes not only the early history of terrestrial arthropods, but also the subsequent expansion of arthropods into major terrestrial habitats.


Author(s):  
Henry Kritzler ◽  
Anne Eidemiller

A dredge equipped with a gate which may be opened by a diver-monitor when it is passing over bottom selected for study and closed elsewhere is described. A meter wheel which activates an electric switch, connected with a battery and counter in the boat, is in contact with the bottom when the gate is open and raised from the bottom when it is closed. This permits the taking of sampling units of uniform predetermined size. Field trials demonstrated that the dredge efficiently captured all categories of animals large enough to be retained by its meshes.The difficulty of obtaining unbiased, representative samples of single populations is compounded by the complexities of aggregates of populations, such as biotic communities, and even more by discontinuities in the dispersion of the constituent species and the habitats in which they live. The probability of taking such unbiased, representative samples of marine communities decreases with the depth of water from which they are obtained. Sampling confidence at a level which may be taken for granted in terrestrial habitats is possible only in the littoral and shallow sublittoral. And this is true only if the investigator is able to assure himself that each sampling unit is excised only from the kind of habitat whose biota he wishes to study. He may achieve this specificity in sampling benthos, for example, by using grabs and discarding material brought up from bottom types not under investigation. Another approach is to engage in a comprehensive, preliminary, systematic exploration so that when he samples for parametric estimates he can place his grab exactly where he knows that the desired habitat exists.


2006 ◽  
Vol 33 (10) ◽  
pp. 893 ◽  
Author(s):  
Hendrik Bargel ◽  
Kerstin Koch ◽  
Zdenek Cerman ◽  
Christoph Neinhuis

The cuticle is the main interface between plants and their environment. It covers the epidermis of all aerial primary parts of plant organs as a continuous extracellular matrix. This hydrophobic natural composite consists mainly of the biopolymer, cutin, and cuticular lipids collectively called waxes, with a high degree of variability in composition and structure. The cuticle and cuticular waxes exhibit a multitude of functions that enable plant life in many different terrestrial habitats and play important roles in interfacial interactions. This review highlights structure–function relationships that are the subjects of current research activities. The surface waxes often form complex crystalline microstructures that originate from self-assembly processes. The concepts and results of the analysis of model structures and the influence of template effects are critically discussed. Recent investigations of surface waxes by electron and X-ray diffraction revealed that these could be assigned to three crystal symmetry classes, while the background layer is not amorphous, but has an orthorhombic order. In addition, advantages of the characterisation of formation of model wax types on a molecular scale are presented. Epicuticular wax crystals may cause extreme water repellency and, in addition, a striking self-cleaning property. The principles of wetting and up-to-date concepts of the transfer of plant surface properties to biomimetic technical applications are reviewed. Finally, biomechanical studies have demonstrated that the cuticle is a mechanically important structure, whose properties are dynamically modified by the plant in response to internal and external stimuli. Thus, the cuticle combines many aspects attributed to smart materials.


Biotropica ◽  
1992 ◽  
Vol 24 (4) ◽  
pp. 488 ◽  
Author(s):  
Michael S. Ross ◽  
Joseph J. O'Brien ◽  
Laura J. Flynn

1993 ◽  
Vol 71 (12) ◽  
pp. 2345-2351 ◽  
Author(s):  
James G. MacCracken ◽  
Victor Van Ballenberghe ◽  
James M. Peek

Use of submergent aquatic plants by North American moose (Alces alces) has been linked to sodium hunger. Habitat preferences, seasonal diets, forage abundance and quality, and population surveys indicated that emergent plants in small shallow ponds were important to moose on the Copper River Delta, Alaska. However, sodium was abundant in terrestrial browse. We propose that foraging in aquatic habitats, particularly on emergent species, may be highly efficient based on the following habitat attributes and behavioral observations: (i) ponds dominated by either emergent or submergent species produced about 4 times more forage than terrestrial habitats, (ii) emergent and submergent plants were more digestible and had higher concentrations of minerals than browse, (iii) use of aquatic habitats followed trends in forage production over the growing season, (iv) indirect evidence suggested that forage intake rates were greater in aquatic habitats, and (v) use of aquatic habitats by male and female moose was in proportion to the sex structure of the population. These data provide consistent circumstantial evidence that use of emergent species, and possibly submergents, may maximize the intake of nutrients and also reduce conflicts between cropping forage and vigilance during a foraging bout.


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