scholarly journals Distribution of Sideroxylon Mascatense (A.DC.) T.D.Penn. and Associated Perennial Plant Communities in Oman

2021 ◽  
Author(s):  
Eric Hopkins ◽  
Rashid Al-Yahyai ◽  
Darach Lupton
Keyword(s):  
Plant Communities ◽  
Altitudinal Gradient ◽  
Population Distribution ◽  
Habitat Destruction ◽  
Perennial Plant ◽  
Transitional Area ◽  
Mountainous Regions ◽  
Key Species ◽  
Conservation Projects ◽  
June July

Abstract BackgroundOman is located on the south-eastern tip of the Arabian Peninsula and is characterized by an arid climate with a vast and varied landscape. Sideroxylon mascatense is a fruit-producing species growing in the arid mountainous regions of North Africa, The Middle East, and Asia. To date, there are no studies describing the population distribution of S. mascatense and the plant communities associated with it in Oman. This study fills this gap.ResultsA series of botanical field surveys was carried out between June 2018 and August 2019 to describe the distribution and associated plant communities of S. mascatense in the Western Hajar Mountains. Sample units were surveyed in the months of June, July, and August as this is the optimal fruiting period of S. mascatense in the Western Hajar Mountains of Oman. Throughout the surveys, 54 perennial non-cultivated species from 32 families were observed growing with S. mascatense. Two-way cluster analysis and indicator species analysis found two main plant communities associated with S. mascatense along an altitudinal gradient. These were the Acridocarpus orientalis-Euphorbia larica community and the Olea europaea-Euryops arabicus community. There was species overlap in the transitional area between the communities where the environmental factors allowed for continuation along the altitudinal gradient. There was no recruitment of S. mascatense observed during the surveys.ConclusionsThe lack of recruitment, along with the threats of overgrazing and habitat destruction, point to an uncertain future for the S. mascatense populations in Oman. As S. mascatense is associated with threatened key species in the Western Hajar Mountains, S. mascatense should be protected and included in conservation projects. This could allow for the establishment of natural recruitment of S. mascatense, thereby preserving the fragile ecosystem of the Western Hajar Mountains and ensuring the future survival of S. mascatense and its associated communities.

scholarly journals Potential Invasiveness for Eucalyptus Species in Florida

2015 ◽  
Vol 8 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Kimberly A. Lorentz ◽  
Patrick J. Minogue
Keyword(s):  
Plant Communities ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Bare Soil ◽  
Bioenergy Crops ◽  
Eucalyptus Species ◽  
Buffer Zones ◽  
Forest Road ◽  
Central Florida ◽  
Perennial Plant

AbstractTo assess the potential invasiveness of common eucalyptus species planted for pulpwood, mulch wood or bioenergy crops, field surveys of eucalyptus seedling recruitment were conducted in north and central Florida locations within seed bearing eucalyptus stands and in the proximate plant communities where seed dispersal may occur. Plant communities included non-grazed pasture, intensively site-prepared forestland, abandoned forest road and upland mixed pine- hardwood forest. No eucalyptus seedlings were found in any of the 310 1-m2 survey plots across the two locations. Second, seed addition studies were conducted to determine the relative potential for seedling emergence and survival among Eucalyptus amplifolia, E. camaldulensis and E. grandis added into plots at two seed densities, under disturbed and nondisturbed conditions, in the understory of the eucalyptus stands and in each of the aforementioned proximate plant communities. Overall, the probability of emergence of added seed was very low (P = 0.0 to 0.0032), and seed density effects were not significant. Emergence was significantly greater in disturbed conditions compared to nondisturbed conditions for seedlings originating from natural seed rain from the eucalyptus canopy in central Florida. The amount of time that seedlings survived was greater for E. camaldulensis compared to the other species but no seedlings survived more than 13 wk. These data indicate that under specific favorable conditions, eucalyptus seedlings may establish within or proximate to planted stands, but the overall level of invasiveness demonstrated by E. amplifolia and E. grandis is low for north or central Florida. The demonstrated role of disturbance in facilitating eucalyptus seedling recruitment suggests that a stable perennial plant community (native grasses) should be established instead of bare soil buffer zones to mitigate spread.

scholarly journals Mountain grassland ecosystems on abandoned agricultural terraces (Russia, North Caucasus)

Hacquetia ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 61-71
Author(s):  
Raisa Gracheva ◽  
Elena Belonovskaya ◽  
Vera Vinogradova
Keyword(s):  
Plant Communities ◽  
Agricultural Landscape ◽  
Landscape Fragmentation ◽  
Slope Aspect ◽  
North Caucasus ◽  
Agricultural Terraces ◽  
Current Increase ◽  
Mountainous Regions ◽  
The North ◽  
Mountain Grassland

Abstract Terraces represent one of the most common agricultural landscape elements in the mountainous regions of the North Caucasus. In the Central and West Caucasus, most of the arable terraces were converted into grasslands for grazing and haymaking 60-70 years ago and then abandoned or underused during the last 20-25 years. The role of abandoned terraces in maintaining the diversity of grasslands of the mountain slopes was studied in the case of eight terraces of different types. Plant communities of subalpine meadows and meadow steppes were distinguished on the terraces depending mainly on slope steepness at the same altitudes and to a lesser extent on the slope aspect. In general, the grasslands of the terrace platforms and those of original unterraced slopes had similar traits. At that, the mesophilous communities on the rich soils of terrace edges and scarp communities similar to vegetation of steep slopes with eroded soils create regular patterns on the terraced slopes. Thus, former agricultural terraces conditioning geodiversity also contribute to the diversity of plant communities and landscape fragmentation. The current increase of temperature and humidity may lead to a reduction of climatic differences of the slopes, and the further convergence of grassland communities can be assumed.

scholarly journals Vegetation recording in forests: Comparison of the Chinese and European approaches

2011 ◽  
Vol 63 (2) ◽  
pp. 469-476 ◽  
Author(s):  
Qiao-Ming Zhang ◽  
De-Xiang Wang ◽  
Anton Fischer
Keyword(s):  
Plant Communities ◽  
Altitudinal Gradient ◽  
Field Survey ◽  
Diversity Index ◽  
Wiener Index ◽  
Herb Layer ◽  
Main Field ◽  
Field Approach ◽  
Plot Size ◽  
Vegetation Study

The field approach underlying a vegetation study influences the results of biodiversity assessments. In our paper we compared two main field survey approaches for forest vegetation recording, the Chinese and the European (?phytosociological?) one, for their differences and efficiency when applied to the plant communities of temperate forests. The Chinese approach uses a design with different plot sizes for recording the tree, shrub and herb layer species, respectively, while the European one uses the same plot size for recording all layers and species. The two approaches result in significant differences in species richness (Simpson?s diversity index and the Shannon-Wiener index), while there is no difference in the evenness index. The European approach has the ability to survey the number of different species more precisely than the Chinese one. For detecting the general patterns of diversity, however, the two approaches have the same ability, demonstrated here for the altitudinal gradient.

scholarly journals Effect of aridity on species assembly in gypsum drylands: a response mediated by the soil affinity of species

AoB Plants ◽  
2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Arantzazu L Luzuriaga ◽  
Pablo Ferrandis ◽  
Joel Flores ◽  
Adrián Escudero
Keyword(s):  
Plant Communities ◽  
Linear Models ◽  
Taxonomic Diversity ◽  
Mean Annual Precipitation ◽  
Change Models ◽  
Perennial Plant ◽  
Arid Conditions ◽  
The Mean ◽  
Maximum Temperatures ◽  
Selection Of

Abstract Previous studies found that plant communities on infertile soils are relatively resistant to climatic variation due to stress tolerance adaptations. However, the species assemblies in gypsum soil habitats require further investigation. Thus, we considered the following questions. (1) Do harsher arid conditions determine the characteristics of the species that form plant assemblages? (2) Is the selection of the species that assemble in arid conditions mediated by their ability to grow on gypsum soils? (3) Is the selection of species that assemble in harsher conditions related to phylogenetically conserved functional traits? Perennial plant communities were analysed in 89 gypsum-soil sites along a 400 km climate gradient from the central to southeastern Iberian Peninsula. Each local assemblage was analysed in 30 × 30 m plots and described based on taxonomic, functional (soil plant affinity) and phylogenetic parameters. The mean maximum temperatures in the hottest month, mean annual precipitation and their interaction terms were used as surrogates for the aridity conditions in generalized linear models. In the hottest locations, the gypsophily range narrowed and the mean gypsophily increased at the community level, thereby suggesting the filtering of species and the dominance of soil specialists in the actual plant assemblies. Drier sites had higher taxonomic diversity. The species that formed the perennial communities were close in evolutionary terms at the two ends of the aridity gradient. The mean maximum temperatures in the hottest month had the main abiotic filtering effect on perennial plant communities, which was mediated by the ability of species to grow on gypsum soils, and thus gypsum specialists dominated the species assemblies in the hottest locations. In contrast, the perennial communities on gypsum soils were relatively resistant to changes in precipitation. Our findings suggest that the warmer environmental conditions predicted by global change models will favour gypsum specialists over generalists.

Increasing densities of leaf-cutting ants (Atta spp.) with proximity to the edge in a Brazilian Atlantic forest

2007 ◽  
Vol 23 (4) ◽  
pp. 501-505 ◽  
Author(s):  
Rainer Wirth ◽  
Sebastian T. Meyer ◽  
Walkiria R. Almeida ◽  
Manoel Vieira Araújo ◽  
Veralucia S. Barbosa ◽  
...  
Keyword(s):  
Plant Communities ◽  
Rain Forest ◽  
Forest Ecosystems ◽  
Agricultural Land ◽  
Ecological Impact ◽  
Habitat Alterations ◽  
Key Species ◽  
Forest Remnants ◽  
Successional Forests ◽  
Leaf Cutting

Leaf-cutting ants (genera Atta and Acromyrmex) have been denoted key species of American rain-forest ecosystems (Fowler et al. 1989) because of their multifarious effects on the vegetation. Being dominant herbivores, cutting up to 13% of the standing leaf crop in a colony's territory per year, they affect directly and significantly individual plants, plant communities and ecosystems (Wirth et al. 2003). The considerable ecological impact of these ants is paralleled by the well-known fact that some species strongly benefit from human-driven habitat alterations and represent prime pests throughout Latin America (Cherrett 1986). Numerous studies have documented populations of leaf-cutting ant to increase with increasing agricultural land use, deforestation and/or disturbance (Fowler et al. 1986, Jaffe & Vilela 1989, Jonkman 1979). Specifically, elevated colony densities have been recorded in (1) transformed vegetation such as pastures (Fowler 1983) and plantations (Jaffe 1986, Oliveira et al. 1998), (2) early successional forests (Vasconcelos & Cherrett 1995), and recently (3) isolated forest remnants (Terborgh et al. 2001).

Landscape and plant community boundaries in biogeography

1997 ◽  
Vol 21 (3) ◽  
pp. 315-353 ◽  
Author(s):  
Martin Kent ◽  
Wendy J. Gill ◽  
Ruth E. Weaver ◽  
Richard P. Armitage
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Geographical Information Systems ◽  
Local Community ◽  
Traditional Approach ◽  
Geographical Information ◽  
Transitional Area ◽  
Moving Window Analysis ◽  
Community Boundaries ◽  
The Subject

The increasing relevance and importance of the subject of landscape ecology to bio geography are introduced. Research into landscape and plant community boundaries, never theless, remains comparatively neglected. In particular, the nature of those boundaries in terms of the patterns of floristic change and related ecosystem properties constitutes a potentially signifi cant new area of research for biogeographers. The term 'ecotone' has traditionally been used to describe boundaries between plant communities and ecosystems at a range of scales. Various definitions are presented and the often confusing terminology surrounding the word 'ecotone' is reviewed. Boundary types range from sharp, clearly defined boundaries (ecotones) between more highly modified plant communities and anthropogenically created land-use types at one extreme, to more gradual and diffuse boundaries (ecoclines) between natural and semi-natural plant communities at the other. It is proposed that the term 'transitional area' is used to describe all types of vegetation boundary when working at the local/community scale. There is little literature of direct significance to the subject of transitional areas. The concept can only be meaningfully discussed in the context of recent developments in the conceptualization of the plant community and these are summarized. The importance of mosaics within plant communities is described and the need to understand and recognize mosaics when studying transitional areas between plant communities is emphasized. The range of research methods available to describe and analyse variations in patterns of floristics and associated environmental variables across transitional areas is then critically reviewed. The potential relevance of remote sensing and geographical information systems, net work analysis and fractals is demonstrated. Ideas on possible adaptations of sampling strategies for the description of floristics and environmental/biotic factors to cater for boundary/transitional area situations are presented and the concept of a rectangular sampling area as an alternative to the more normal linear transect is introduced. The traditional approach to the description of vegetation change across boundaries using transects and similarity coefficients has now been superseded by new developments, notably moving-window analysis, the Mantel test, pattern analysis, semi-variograms, spectral analysis and analysis for spatial autocorrelation, and the scope of these methods is summarized. Finally, the dynamics of plant communities and their boundaries are considered and the implications of research into transitional areas for vegetation management and biological conserv ation are assessed. The importance of this whole subject as a possible new focus for biogeography and spatial ecology is then reiterated.

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