scholarly journals Re-Establishment Techniques and Transplantations of Charophytes to Support Threatened Species

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1830
Author(s):  
Irmgard Blindow ◽  
Maria Carlsson ◽  
Klaus van de Weyer

Re-establishment of submerged macrophytes and especially charophyte vegetation is a common aim in lake management. If revegetation does not happen spontaneously, transplantations may be a suitable option. Only rarely have transplantations been used as a tool to support threatened submerged macrophytes and, to a much lesser extent, charophytes. Such actions have to consider species-specific life strategies. K-strategists mainly inhabit permanent habitats, are perennial, have low fertility and poor dispersal ability, but are strong competitors and often form dense vegetation. R-strategists are annual species, inhabit shallow water and/or temporary habitats, and are richly fertile. They disperse easily but are weak competitors. While K-strategists easily can be planted as green biomass taken from another site, rare R-strategists often must be reproduced in cultures before they can be planted on-site. In Sweden, several charophyte species are extremely rare and fail to (re)establish, though apparently suitable habitats are available. Limited dispersal and/or lack of diaspore reservoirs are probable explanations. Transplantations are planned to secure the occurrences of these species in the country. This contribution reviews the knowledge on life forms, dispersal, establishment, and transplantations of submerged macrophytes with focus on charophytes and gives recommendations for the Swedish project.

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8794 ◽  
Author(s):  
Gang Ni ◽  
Taeho Kim ◽  
Youngheon Shin ◽  
Jina Park ◽  
Yucheol Lee ◽  
...  

Chitons are a group of marine mollusks (class Polyplacophora) characterized by having eight articulating shell plates on their dorsal body surface. They represent suitable materials for studying the spatiotemporal processes that underlie population differentiation and speciation in ocean environments. Here we performed population genetic analyses on the northwestern Pacific chiton Acanthochitona cf. rubrolineata (Lischke, 1873) using two mitochondrial gene fragments (COI and 16S) from 180 individuals sampled from 11 populations among the coastal waters of Korea, Japan, and China. The phylogenetic network uncovered a reticulated relationship with several sub-haplogroups for all A. cf. rubrolineata haplotypes. SAMOVA analyses suggested the best grouping occurred at three groups (ΦCT = 0.151, P < 0.0001), which geographically corresponds to hydrographic discontinuity among the coastal regions of Korea, Japan, and China. The assumed limited dispersal ability of A. cf. rubrolineata, coupled with northeasterly flowing, trifurcate warm currents, might have contributed to the genetic differentiation among the three groups. Meanwhile, a high level of within-group genetic homogeneity was detected, indicating extensive coastal currents might facilitate gene flow among the populations within each group. Bayesian skyline plots demonstrated significant population expansion after the Last Glacial Period (110-25 thousand years ago) for all studied populations except the Japan group. Together these results suggest that the present-day phylogeographic patterns of A. cf. rubrolineata are strongly affected by the interplay of historical and/or contemporary oceanography and species-specific life-history features.


2021 ◽  
Vol 9 ◽  
Author(s):  
Hui Zhang ◽  
Qifang He ◽  
Shree Prakash Pandey ◽  
Kai Jiang ◽  
Chen Wang

Understanding functional traits that capture species response to overgrazing can help optimize ecosystem functioning. However, most studies have ignored the effects of life-form on the response of above- and below-ground traits to overgrazing. Here, we determined whether the above- and below-ground traits respond similarly to overgrazing; and does the response of above- and below-ground traits to overgrazing vary between the species of annual vs. perennial life-forms. We compared common grassland species between fenced and overgrazed meadows at four elevations (from 3000 to 3600 m), spanning an area of ∼200 square kilometers on the Qinghai-Tibetan Plateau. We found overgrazing resulted in large removal of perennial species at all elevations, which forced perennial species to alter their above- and below-ground traits so that they could shift from resource conservation to resource acquisition to avoid overgrazing. In contrast, overgrazing promoted annual species at all elevation, thus annual species did not make any response to overgrazing. These findings bridge the gap in the literature for the influence of annual vs. perennial life-forms on species-specific response at both above-, and below-ground levels during overgrazing. More important, these results can facilitate selecting species for sustainable ecosystem managements and restoration from overgrazing.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Wolfgang Paill ◽  
Stephan Koblmüller ◽  
Thomas Friess ◽  
Barbara-Amina Gereben-Krenn ◽  
Christian Mairhuber ◽  
...  

The last ice age considerably influenced distribution patterns of extant species of plants and animals, with some of them now inhabiting disjunct areas in the subarctic/arctic and alpine regions. This arctic-alpine distribution is characteristic for many cold-adapted species with a limited dispersal ability and can be found in many invertebrate taxa, including ground beetles. The ground beetle Pterostichus adstrictus Eschscholtz, 1823 of the subgenus Bothriopterus was previously known to have a holarctic-circumpolar distribution, in Europe reaching its southern borders in Wales and southern Scandinavia. Here, we report the first findings of this species from the Austrian Ötztal Alps, representing also the southernmost edge of its currently known distribution, confirmed by the comparison of morphological characters to other Bothriopterus species and DNA barcoding data. Molecular data revealed a separation of the Austrian and Finish specimens with limited to no gene flow at all. Furthermore, we present the first data on habitat preference and seasonality of P. adstrictus in the Austrian Alps.


Author(s):  
Maria Papadopoulou ◽  
Ioannis Tsiripidis ◽  
Sampson Panajiotidis ◽  
Georgios Fotiadis ◽  
Daniel Veres ◽  
...  

AbstractDue to the complex relationship between pollen and vegetation, it is not yet clear how pollen diagrams may be interpreted with respect to changes in floristic diversity and only a few studies have hitherto investigated this problem. We compare pollen assemblages from moss samples in two southeastern European forests with the surrounding vegetation to investigate (a) their compositional similarity, (b) the association between their diversity characteristics in both terms of richness and evenness, and (c) the correspondence of the main ecological gradients that can be revealed by them. Two biogeographical regions with different vegetation characteristics, the Pieria mountains (north central Greece) and the slopes of Ciomadul volcano (eastern Romania), were chosen as divergent examples of floristic regions, vegetation structure and landscape openness. Pollen assemblages are efficient in capturing the presence or absence, rather than the abundance in distribution of plants in the surrounding area and this bias increases along with landscape openness and vegetation diversity, which is higher in the Pieria mountains. Pollen assemblages and vegetation correlate better in terms of richness, that is, low order diversity indices. Relatively high correlation, in terms of evenness, could be potentially found in homogenous and species poor ecosystems as for Ciomadul. Composition and diversity of woody, rather than herb, vegetation is better reflected in pollen assemblages of both areas, especially for Pieria where a direct comparison of the two components was feasible, although this depends on the species-specific pollen production and dispersal, the openness of landscape and the overall diversity of vegetation. Gradients revealed by pollen assemblages are highly and significantly correlated with those existing in vegetation. Pollen assemblages may represent the vegetation well in terms of composition, diversity (mainly richness) and ecological gradients, but this potential depends on land use, vegetation structure, biogeographical factors and plant life forms.


2015 ◽  
Vol 95 (8) ◽  
pp. 1607-1612 ◽  
Author(s):  
E.S. Mekhova ◽  
P.Y. Dgebuadze ◽  
V.N. Mikheev ◽  
T.A. Britayev

Previous experiments with the comatulid Himerometra robustipinna (Carpenter, 1881) demonstrated intensive host-to-host migration processes for almost all symbiotic species both within host aggregations and among hosts separated by several metres. The aim of this study was to check the ability of symbionts to complete long-distance migrations, by means of two in situ experiments which depopulated the crinoid host. Two different sets of field experiments were set up: exposure of depopulated crinoids (set 1) on stony ‘islands’ isolated from native crinoid assemblages by sandy substrate, and (set 2) in cages suspended in the water column. Hosts from set 1 were exposed for 1, 2, 3 and 4 weeks to assess whether substrate has an influence on the symbionts' long-distance migrations. In set 2 cages were exposed for 10–11 days, aiming to check whether symbionts were able to disperse through the water column with currents. These experiments allow the conclusion that post-settled symbionts can actively migrate among their hosts. Symbionts are able to reach their hosts by employing two different ‘transport corridors’, by drifting or swimming in water column, and by moving on the bottom. Comparison of experimental results allows the division of symbionts into two conventional groups according to the dispersal ability of their post-settled stages: (1) species able to complete long-distance migrations, (2) species unable to migrate or having limited dispersal ability. The finding of the free-living shrimp Periclimenes diversipes Kemp, 1922 in set 2 raises the question about the factors that affect such a high degree of specialization of crinoid assemblages.


Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Ana Luísa Biondi Fares ◽  
Raimundo Luiz Morais de Sousa ◽  
Ely Simone Cajueiro Gurgel ◽  
André dos Santos Bragança Gil ◽  
Carlos Alberto Santos da Silva ◽  
...  

Abstract The Amazon possesses the largest fluvial system on the planet, harboring a diverse biota. Still, many species remain undescribed, because of the Amazon’s immense scale and complexity, and because many habitats are now increasingly under pressure from anthropogenic activities. Macrophytes are important to physical and biological processes in aquatic ecosystems but remain poorly studied in Northern Brazil. The objective of this study was to provide a checklist of macrophyte species that occur in municipalities that form part of the Arc of Deforestation, Pará state, Brazil, bringing information on their habits and life-forms. We sampled 36 sites at three types of aquatic ecosystems (streams, ponds and lakes). In total, we recorded 50 species, 38 genera and 24 families. Most species were amphibious or emergent. Degraded streams have environmental characteristics similar to lentic habitats, which could provide more suitable habitats for macrophytes that otherwise would not occur in lotic habitats, thus explaining the higher diversity in these ecosystems. Macrophyte diversity in this region follows similar patterns to other Brazilian regions. This study contributes to the assessment of aquatic macrophytes in the Amazon, especially in more degraded regions, such as the Amazon deforestation arc.


2020 ◽  
Vol 12 (3) ◽  
pp. 1282 ◽  
Author(s):  
Hari Prasad Sharma ◽  
Bhagawat Rimal ◽  
Mingxia Zhang ◽  
Sandhya Sharma ◽  
Laxman Prasad Poudyal ◽  
...  

Anthropogenic activities have driven many wildlife species towards extinction. Among these species, the geographic distributions of many are poorly documented, which can limit the effectiveness of conservation. The critically endangered Chinese pangolin (Manis pentadactyla) is experiencing population decline throughout its range due to land-use changes and illegal trade for food and traditional medicine. Using distribution records and maximum entropy modeling, we predicted the potential distribution of the Chinese pangolin across Nepal. Most suitable potential habitats of the Chinese pangolin occurred in forest areas of the mid-hill region in central and eastern Nepal, followed by cultivated land. Almost all potential suitable habitats of the Chinese pangolin occurred outside of protected areas, and most of them were encroached upon by cultivated land, human settlements, and infrastructure developments. The results from this study provide baseline information on the potential suitable habitats of the Chinese pangolin in Nepal, which helps to develop site- and species-specific management plans and to identify priority areas to minimize the current threats to the pangolin and enhance the stewardship of species conservation.


Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1160 ◽  
Author(s):  
Yu Cao ◽  
Yongwei Zhi ◽  
Erik Jeppesen ◽  
Wei Li

More frequent extreme climate events (e.g., extreme precipitation) are to be expected in the future, and such events may potentially have significant effects on freshwater ecosystems. In the present mesocosm study, the effects of simulated extreme precipitation on submerged macrophytes were evaluated for three different macrophyte community (MC) treatments (MC1, MC2 and MC3). MC1 consisted of only Vallisneria denseserrulata, while MC2 and MC3 included three and six species of various growth forms. Two treatments of extreme precipitation (EP) were simulated—an extreme treatment (E) simulating a sudden increase of water level from 75 cm to 150 cm within one day and a gradual treatment (G) simulating an increase to the same water level within 3 months, combined with two control treatments. Total macrophyte community biomass was resilient to the EP and MC treatments, while species-specific variations in responses, in terms of biomass, maximum height, and sexual reproduction, were found. For instance, E led to earlier flowering of Potamogeton lucens and production of more flowers, while it had adverse effects on the flowering of Ottelia alismoides. We conclude that freshwater ecosystems with high coverage of submerged macrophytes may be overall resilient to extreme precipitation under nutrient-limited conditions, especially communities with diverse growth forms.


Author(s):  
Sarah L. Sokol-Borrelli ◽  
Rachel S. Coombs ◽  
Jon P. Boyle

Stage conversion is a critical life cycle feature for several Apicomplexan parasites as the ability to switch between life forms is critical for replication, dissemination, pathogenesis and ultimately, transmission to a new host. In order for these developmental transitions to occur, the parasite must first sense changes in their environment, such as the presence of stressors or other environmental signals, and then respond to these signals by initiating global alterations in gene expression. As our understanding of the genetic components required for stage conversion continues to broaden, we can better understand the conserved mechanisms for this process and unique components and their contribution to pathogenesis by comparing stage conversion in multiple closely related species. In this review, we will discuss what is currently known about the mechanisms driving stage conversion in Toxoplasma gondii and its closest relatives Hammondia hammondi and Neospora caninum. Work by us and others has shown that these species have some important differences in the way that they (1) progress through their life cycle and (2) respond to stage conversion initiating stressors. To provide a specific example of species-specific complexities associated with stage conversion, we will discuss our recent published and unpublished work comparing stress responses in T. gondii and H. hammondi.


Zootaxa ◽  
2009 ◽  
Vol 2264 (1) ◽  
pp. 1-22 ◽  
Author(s):  
ADALGISA GUGLIELMINO ◽  
CHRISTOPH BÜCKLE

A small sector of Northern Apennines the Tuscan-Emilian Apennines constitutes an interesting diversity centre of a new Verdanus species group closely related to V. bensoni and the V. limbatellus group. It consists of three species: V. tyrannus sp. nov., V. saurosus sp. nov. and V. rosaurus sp. nov., the latter with two subspecies, V. rosaurus rosaurus ssp. nov. and V. rosaurus rex ssp. nov., which doubtless form a monophyletic group (V. rosaurus group). Data on their distribution, ecology and life cycle are added to their original descriptions. The new taxa live allopatrically in a very restricted area and thus occupy a distribution gap of another species group of Verdanus, the V. abdominalis group, present in Italy in the mountain regions of the Alps and Central and Southern Apennines. A hypothesis of the origin of the new taxa is presented based on the ecological conditions in the Tuscan-Emilian Apennines during the last Postglacial period and on the limited dispersal ability of these normally brachypterous insects. Possible synapomorphic characters and phylogenetic relationships of the new taxa with each other and with V. bensoni (China) and the V. limbatellus group (V. limbatellus (Zetterstedt), V. kyrilli (Emeljanov), V. sichotanus (Anufriev), V. kaszabi (Dlabola)) are discussed and a cladistic analysis is conducted. Comparing V. bensoni and the V. limbatellus group on the one hand and the V. rosaurus group on the other, some morphological characters appear to change often in parallel on the same paths, independently from the phylogenetic hypothesis. Remarkably, within the same morphological characters the range of variation among species inhabiting the comparatively minute area of the Tuscan-Emilian Apennines is similar to that found among other taxa distributed across vast areas of northern and central Eurasia.


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