scholarly journals Shaping the Ecotone Zone in Forest Communities That Are Adjacent to Expressway Roads

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1490
Author(s):  
Justyna Czaja ◽  
Zbigniew Wilczek ◽  
Damian Chmura

As a result of forest fragmentation, ecotones have become an important contribution to the landscape. The areas that include ecotones are constantly growing, thus creating new habitats for plants and animals. The factor that has the greatest impact on the configuration and extent of an ecotone is called the “edge effect”. The aim of this study was to determine the width of the ecotones in forests that are adjacent to an expressway and to characterize the edge effect they produced. The research was performed along ten transects situated at the edge of a forest and in the interior part of a forest (plots from 0 to 200 m). The structures of the forest stand, trees, shrubs, dwarf shrubs and herbs were determined and data on the species composition and species cover were also collected. Results of the statistical analyses (linear mixed models as well as detrended and canonical correspondence analyses) indicated significant changes in the structure, species composition, and species turnover that were dependent on the distance from the edge of the forest. It was shown that shrubs (cover, density, species richness) were the most affected while vascular plants were the least affected. However, the changes were ambiguous. There was either an increase or decrease in the individual parameters of the forest structure and the coverage of forest species. The extent of the forest edge began at a minimum distance of 0–20 m.

2016 ◽  
Vol 77 (3) ◽  
pp. 519-526 ◽  
Author(s):  
C. S. Almeida ◽  
P. F. Cristaldo ◽  
D. F. Florencio ◽  
E. J. M. Ribeiro ◽  
N. G. Cruz ◽  
...  

Abstract Habitat fragmentation is considered to be one of the biggest threats to tropical ecosystem functioning. In this region, termites perform an important ecological role as decomposers and ecosystem engineers. In the present study, we tested whether termite community is negatively affected by edge effects on three fragments of Brazilian Atlantic Rainforest. Termite abundance and vegetation structure were sampled in 10 transects (15 × 2 m), while termite richness, activity, and soil litter biomass were measured in 16 quadrants (5 × 2 m) at forest edge and interior of each fragment. Habitat structure (i.e. number of tree, diameter at breast height and soil litter biomass) did not differ between forest edge and interior of fragments. Termite richness, abundance and activity were not affected by edge effect. However, differences were observed in the β diversity between forest edge and interior as well as in the fragments sampled. The β diversity partitioning indicates that species turnover is the determinant process of termite community composition under edge effect. Our results suggest that conservation strategies should be based on the selection of several distinct sites instead of few rich sites (e.g. nesting).


2017 ◽  
Vol 168 (3) ◽  
pp. 127-133
Author(s):  
Matthew Parkan

Airborne LiDAR data: relevance of visual interpretation for forestry Airborne LiDAR surveys are particularly well adapted to map, study and manage large forest extents. Products derived from this technology are increasingly used by managers to establish a general diagnosis of the condition of forests. Less common is the use of these products to conduct detailed analyses on small areas; for example creating detailed reference maps like inventories or timber marking to support field operations. In this context, the use of direct visual interpretation is interesting, because it is much easier to implement than automatic algorithms and allows a quick and reliable identification of zonal (e.g. forest edge, deciduous/persistent ratio), structural (stratification) and point (e.g. tree/stem position and height) features. This article examines three important points which determine the relevance of visual interpretation: acquisition parameters, interactive representation and identification of forest characteristics. It is shown that the use of thematic color maps within interactive 3D point cloud and/or cross-sections makes it possible to establish (for all strata) detailed and accurate maps of a parcel at the individual tree scale.


2003 ◽  
Vol 69 (7) ◽  
pp. 4012-4018 ◽  
Author(s):  
Ariel Maoz ◽  
Ralf Mayr ◽  
Siegfried Scherer

ABSTRACT The temporal stability and diversity of bacterial species composition as well as the antilisterial potential of two different, complex, and undefined microbial consortia from red-smear soft cheeses were investigated. Samples were collected twice, at 6-month intervals, from each of two food producers, and a total of 400 bacterial isolates were identified by Fourier-transform infrared spectroscopy and 16S ribosomal DNA sequence analysis. Coryneform bacteria represented the majority of the isolates, with certain species being predominant. In addition, Marinolactobacillus psychrotolerans, Halomonas venusta, Halomonas variabilis, Halomonas sp. (106 to 107 CFU per g of smear), and an unknown, gram-positive bacterium (107 to 108 CFU per g of smear) are described for the first time in such a consortium. The species composition of one consortium was quite stable over 6 months, but the other consortium revealed less diversity of coryneform species as well as less stability. While the first consortium had a stable, extraordinarily high antilisterial potential in situ, the antilisterial activity of the second consortium was lower and decreased with time. The cause for the antilisterial activity of the two consortia remained unknown but is not due to the secretion of soluble, inhibitory substances by the individual components of the consortium. Our data indicate that the stability over time and a potential antilisterial activity are individual characteristics of the ripening consortia which can be monitored and used for safe food production without artificial preservatives.


2016 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Poliana Gabriella Araújo Mendes ◽  
Maria Amanda Menezes Silva ◽  
Tassiane Novacosque Feitosa Guerra ◽  
Ana Carolina Borges Lins-e-Silva ◽  
Airton de Deus Cysneiros Cavalcanti ◽  
...  

ABSTRACT The woody plants in an edge area formed approximately 35 years ago in an Atlantic Forest fragment in northeastern Brazil were examined, and three environments defined: edge, intermediate, and interior. Canopy tree densities and basal areas were found to be similar in all three environments, and also similar to previous published studies in the same region; species richness was greatest at the forest edge. The understory showed greater species richness in the forest interior, but greater diversity and equitability in the intermediate environment. Understory environments close to the forest edge demonstrated larger stem diameters than in the forest interior, although at lesser densities and with smaller total basal areas. Our results indicated the existence of distinct patterns in canopy and understory that most likely reflect differences in the response times of these two vegetation layers, with the understory being more sensitive to alterations in environmental structure.


2020 ◽  
Author(s):  
Devin R. Leopold ◽  
Kabir G. Peay ◽  
Peter M. Vitousek ◽  
Tadashi Fukami

AbstractEricaceous plants rely on ericoid mycorrhizal fungi for nutrient acquisition. However, the factors that affect the composition and structure of these fungal communities remain largely unknown. Here, we use a 4.1-myr soil chronosequence in Hawaii to test the hypothesis that changes in nutrient availability with soil age determine the diversity and species composition of fungi associated with ericoid roots. We sampled roots of a native Hawaiian plant, Vaccinium calycinum, and used DNA metabarcoding to quantify changes in fungal diversity and species composition. We also used a fertilization experiment at the youngest and oldest sites to assess the importance of nutrient limitation. We found an increase in diversity and a clear pattern of species turnover across the chronosequence, driven largely by putative ericoid mycorrhizal fungi. Fertilization with nitrogen at the youngest site and phosphorus at the oldest site reduced total fungal diversity, suggesting a direct role of nutrient limitation. Our results also reveal the presence of novel fungal species associated with Hawaiian Ericaceae and suggest a greater importance of phosphorus availability for communities of ericoid mycorrhizal fungi than is generally assumed.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Tiantian Jiang ◽  
Xuecheng Yang ◽  
Yonglin Zhong ◽  
Qiming Tang ◽  
Ying Liu ◽  
...  

Bothalia ◽  
2007 ◽  
Vol 37 (2) ◽  
pp. 249-258 ◽  
Author(s):  
M. J. S. Kellerman ◽  
M. W. Van Rooyen

Seasonal variation in seed bank size and species composition of five selected habitat types within the Tembe Elephant Park. South Africa, was investigated. At three-month intervals, soil samples were randomly collected from five different habitat types: a, Licuati forest; b, Licuati thicket; c, a bare or sparsely vegetated zone surrounding the forest edge, referred to as the forest/grassland ecotone; d, grassland; and e, open woodland. Most species in the seed bank flora were either grasses, sedges, or forbs, with hardly any evidence of woody species. The Licuati forest and thicket soils produced the lowest seed densities in all seasons.  Licuati forest and grassland seed banks showed a two-fold seasonal variation in size, those of the Licuati thicket and woodland a three-fold variation in size, whereas the forest/grassland ecotone maintained a relatively large seed bank all year round. The woodland seed bank had the highest species richness, whereas the Licuati forest and thicket soils were poor in species. Generally, it was found that the greatest correspondence in species composition was between the Licuati forest and thicket, as well as the forest/grassland ecotone and grassland seed bank floras.


Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 680 ◽  
Author(s):  
Liangliang Huang ◽  
Jian Huang ◽  
Zhiqiang Wu ◽  
Yuanmin Mo ◽  
Qi Zou ◽  
...  

Beta diversity partitioning has currently received much attention in research of fish assemblages. However, the main drivers, especially the contribution of spatial and hydrological variables for species composition and beta diversity of fish assemblages are less well studied. To link species composition to multiple abiotic variables (i.e., local environmental variables, hydrological variables, and spatial variables), the relative roles of abiotic variables in shaping fish species composition and beta diversity (i.e., overall turnover, replacement, and nestedness) were investigated in the upstream Lijiang River. Species composition showed significant correlations with environmental, hydrological, and spatial variables, and variation partitioning revealed that the local environmental and spatial variables outperformed hydrological variables, and especially abiotic variables explained a substantial part of the variation in the fish composition (43.2%). The overall species turnover was driven mostly by replacement (87.9% and 93.7% for Sørensen and Jaccard indices, respectively) rather than nestedness. Mantel tests indicated that the overall species turnover (ßSOR and ßJAC) and replacement (ßSIM and ßJTU) were significantly related to hydrological, environmental, and spatial heterogeneity, whereas nestedness (ßSNE or ßJNE) was insignificantly correlated with abiotic variables (P > 0.05). Moreover, the pure effect of spatial variables on overall species turnover (ßSOR and ßJAC) and replacement (ßSIM and ßJTU), and the pure effect of hydrological variables on replacement (ßSIM and ßJTU), were not important (P > 0.05). Our findings demonstrated the relative importance of interactions among environmental, hydrological, and spatial variables in structuring fish assemblages in headwater streams; these fish assemblages tend to be compositionally distinct, rather than nested derivatives of one another. Our results, therefore, indicate that maintaining natural flow dynamics and habitat continuity are of vital importance for conservation of fish assemblages and diversity in headwater streams.


2017 ◽  
Vol 68 (5) ◽  
pp. 954 ◽  
Author(s):  
Cristina Stenert ◽  
Bruna Ehlert ◽  
Arthur Cardoso Ávila ◽  
Francisco Diogo Rocha Sousa ◽  
Fernanda Mara Esquinatti ◽  
...  

Exotic pine invasion affects native wetland communities in the Southern Hemisphere by changing the hydrological regimen and physicochemical characteristics. Studies evaluating the emergence of aquatic invertebrates from dormant stages are vital to identify the resilience of aquatic communities in ponds invaded by exotic pine species. In the present study, we tested the hypotheses that: (1) pine invasion decreases the richness of drought-resistant aquatic invertebrates in ponds; (2) pine invasion modifies the invertebrate composition in ponds; and (3) these differences in species composition (β diversity) are associated primarily with species turnover. Dry sediment samples were collected from three natural ponds in native grassland and three ponds in a pine invasion matrix in southern Brazil. In all, 7205 invertebrates, primarily represented by cladocerans (18 species), were sampled after rewetting dry sediments. Pine invasion decreased the richness of aquatic invertebrates because the natural ponds had almost 60% more species and a higher number of estimated species than the pine ponds. The composition differed between natural and pine ponds, and this difference in species composition (β diversity) was associated primarily with the replacement of some species by others. The presence of pine appears to alter colonisation and survival rates of aquatic invertebrates that aestivate in dry sediments in southern Brazil wetlands.


2019 ◽  
Vol 97 (7) ◽  
pp. 588-596 ◽  
Author(s):  
D.H.A. Melo ◽  
B.K.C. Filgueiras ◽  
C.A. Iserhard ◽  
L. Iannuzzi ◽  
A.V.L. Freitas ◽  
...  

Habitat loss and fragmentation have drastically altered the availability and quality of tropical forest habitats, but information on how such changes influence local biodiversity is still insufficient. Here, we examine the effects of both patch and landscape metrics on fruit-feeding butterfly assemblages in a fragmented landscape of the Brazilian Atlantic Forest. Our study was carried out in three habitat types: eight fragments (ranging from 8 to 126 ha), eight areas of forest edge (50 m from forest border), and eight areas of forest interior (>200 m from forest border) of the largest remnant (3500 ha) of the Atlantic Forest of northeast Brazil. Our results demonstrated that fragment area is negatively correlated with observed and estimated richness and abundance of butterflies, whereas habitat type is correlated with estimated richness and abundance of butterflies. Species composition responded to habitat type, fragment area, and distance between sample units. These findings illustrated (i) fruit-feeding butterfly sensitivity to habitat loss and fragmentation, (ii) that species composition and abundance are adequate parameters to access the responses of fruit-feeding butterflies to habitat loss and fragmentation, and (iii) the relevance of a heterogeneous and connected landscape for conservation of butterflies, where small fragments are important for generalist or open-habitat specialists and large remnants are key for disturbance-sensitive and threatened taxa.


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