scholarly journals Phytosociological surveys: tools for weed science?

2013 ◽  
Vol 31 (2) ◽  
pp. 469-482 ◽  
Author(s):  
G. Concenço ◽  
M. Tomazi ◽  
I.V.T. Correia ◽  
S.A. Santos ◽  
L. Galon

In simple terms, a phytosociological survey is a group of ecological evaluation methods whose aim is to provide a comprehensive overview of both the composition and distribution of plant species in a given plant community. To understand the applicability of phytosociological surveys for weed science, as well as their validity, their ecological basis should be understood and the most suitable ones need to be chosen, because cultivated fields present a relatively distinct group of selecting factors when compared to natural plant communities. For weed science, the following sequence of steps is proposed as the most suitable: (1) overall infestation; (2) phytosociological tables/graphs; (3) intra-characterization by diversity; (4) inter-characterization and grouping by cluster analysis. A summary of methods is established in order to assist Weed Science researchers through their steps into the realm of phytosociology.

2020 ◽  
Author(s):  
Abyot Dibaba Hundie ◽  
Teshome Soromessa Urgessa ◽  
Bikila Warkineh Dullo

Abstract Background This study was carried out in Gerba Dima Forest, South-Western Ethiopia, to determine the floristic composition, species diversity and community types along environmental gradients. Ninety sample plots having a size of 25 × 25 m (625 m2) were laid by employing stratified random sampling. Nested plots were used to sample plants of different sizes and different environmental variables. All woody plant species with Diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 1.5 m were recorded in 25 m X 25 m plots. Within the major plots, five 3 m x 3 m subplots (9 m2) was used to collect shrubs with dbh < 2.5 cm and > 1.5 m height. Within each 9 m2subplots, two 1 m2 subplots were used to collect data on the species and abundance of herbaceous plants. Hierarchical (agglomerative) cluster analysis was performed using the free statistical software R version 3.6.1 using package cluster to classify the vegetation into plant community types. Redundancy Analysis (RDA) ordination was used in describing the pattern of plant communities along an environmental gradient. Result One hundred and eighty plant species belonging to 145 genera, 69 families and comprising of 15 endemic species were recorded. Cluster analysis resulted in five different plant communities and this result was supported by the ordination result. RDA result showed altitude was the main environmental variable in determining the plant communities. The ANOVA test indicated that the five community types differ significantly from each other with regard to EC and K. Conclusions The studied forest can play a significant role in biodiversity conservation since it harbours high species diversity and richness. Thus, all Stakeholders including Oromia Forest and wildlife enterprise (OFWE) and the regional government should work to designate the forest as a biosphere reserve and being registered under UNESCO.


1989 ◽  
Vol 67 (4) ◽  
pp. 1126-1136 ◽  
Author(s):  
M. Muc ◽  
B. Freedman ◽  
J. Svoboda

A cluster analysis was used to apportion 136 stands in a High Arctic lowland among six vascular plant community types. These communities are described on the basis of the average prominence values of vascular species and the total cover of macroalgae, bryophytes, lichens, and vascular plants within the designated clusters of stands. The relationships among the community types was explored by a detrended correspondence analysis. The ordination of stands showed considerable floristic overlap among the most widespread plant communities on the lowland. This largely reflects the microtopographic heterogeneity of the sites, the relatively depauperate flora of the High Arctic, and the considerable ecological amplitude of the most prominent vascular plant species.


2021 ◽  
Author(s):  
Abyot Dibaba Hundie ◽  
Teshome Soromessa Urgessa ◽  
Bikila Warkineh Dullo

Abstract Background: This study was carried out in Gerba Dima Forest, South-Western Ethiopia, to determine the floristic composition, species diversity and community types along environmental gradients. Ninety sample plots having a size of 25 X 25m (625m2) were laid by employing stratified random sampling. Nested plots were used to sample plants of different sizes and different environmental variables. All woody plant species with Diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 1.5m were recorded in 25 m X 25 m plots. Hierarchical (agglomerative) cluster analysis was performed using the free statistical software R version 3.6.1 using package cluster to classify the vegetation into plant community types. Redundancy Analysis (RDA) ordination was used in describing the pattern of plant communities along an environmental gradient. Result: One hundred and eighty plant species belonging to 145 genera, 69 families and comprising of 15 endemic species were recorded. Of these, 52 species (28.9%) were trees, 6 species (3.33%) were Trees/shrubs, 31 species (17.22%) were shrubs, 76 species (42.22%) were herbs, and 15 species (8.33%) were Lianas. Rubiaceae, Acanthaceae and Asteraceae were the richest family each represented by 11 genera and 11 species (6.11%), 9 genera and 11 species (6.11%), 6 genera and 11 species (6.11%), respectively of total floristic composition. Cluster analysis resulted in five different plant communities and this result was supported by the ordination result. RDA result showed altitude was the main environmental variable in determining the plant communities. The ANOVA test indicated that the five community types differ significantly from each other with regard to Electrical Conductivity and Potassium. Conclusions: Description of floristic diversity of species in Gerba Dima forest revealed the presence of high species diversity and richness. The presence of endemic plant species in the study forest shows the potential of the area for biodiversity conservation.


2020 ◽  
Author(s):  
Abyot Dibaba Hundie ◽  
Teshome Soromessa Urgessa ◽  
Bikila Warkineh Dullo

Abstract Background: This study was carried out in Gerba Dima Forest, South-Western Ethiopia, to determine the floristic composition, species diversity and community types along environmental gradients. Ninety sample plots having a size of 25 X 25m (625m 2 ) were laid by employing stratified random sampling. Nested plots were used to sample plants of different sizes and different environmental variables. All woody plant species with Diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 1.5m were recorded in 25 m X 25 m plots. Within the major plots, five 3m x 3m subplots (9m 2 ) was used to collect shrubs with dbh < 2.5 cm and > 1.5m height. Within each 9m 2 subplots, two 1m 2 subplots were used to collect data on the species and abundance of herbaceous plants. Hierarchical (agglomerative) cluster analysis was performed using the free statistical software R version 3.6.1 using package cluster to classify the vegetation into plant community types. Redundancy Analysis (RDA) ordination was used in describing the pattern of plant communities along an environmental gradient. Result: One hundred and eighty plant species belonging to 145 genera, 69 families and comprising of 15 endemic species were recorded. Cluster analysis resulted in five different plant communities and this result was supported by the ordination result. RDA result showed altitude was the main environmental variable in determining the plant communities. The ANOVA test indicated that the five community types differ significantly from each other with regard to EC and K. Conclusions: The studied forest can play a significant role in biodiversity conservation since it harbours high species diversity and richness. Thus, all Stakeholders including Oromia Forest and wildlife enterprise (OFWE) and the regional government should work to designate the forest as a biosphere reserve and being registered under UNESCO. Keyword s: Gerba Dima; Indicator species; Moist Afromontane Forest; Species diversity


2012 ◽  
Vol 468-471 ◽  
pp. 2764-2770
Author(s):  
Shan Lu ◽  
Bo Chen ◽  
Shao Qing Hu ◽  
Jing Jing Zhang ◽  
Jun Hao Jiang ◽  
...  

Urban close-to-nature plant community is a sustainable design and construction philosophy of landscape greenbelt planning. However, there is no explicit guide for constructing close-to-nature plant community Based on the analysis of community structure and characteristics of 10 typical natural plant communities in the West Lake Scenic Area in Hangzhou and summary of the features of natural community, as well as the analysis of plant landscape of Hangzhou Huagangguanyu Park to prove that the close-to-nature man-made plant community and natural plant community are interrelated in respect of vegetation composition and community structure, this paper puts forward to the essential construction methods of the close-to-nature landscape community, providing theoretical basis for research and construction of urban close-to-nature landscape plant community in China.


2021 ◽  
Author(s):  
◽  
Guyo Duba Gufu

<p>Biological invasion by non-native plant species has often been cited as a cause of native biodiversity loss. While the outcome of species invasions depends on interactions between exotic and resident native species, most studies of biological invasions have focused solely on the direct negative impacts of non-indigenous species on native biota. Although investigations of the role of competition in shaping natural plant communities were dominant in the previous generations and are still popular, more recent experimental research has uncovered the striking influence of facilitation on community dynamics. This thesis aims to investigate competitive and facilitative influence of the invasive South African iceplant (Carpobrotus edulis) on Spinifex sericeus, a native foredune grass species, with particular reference to implications of these interactions for dune restoration in New Zealand. It further explores the growth rates, substrate preferences and mating systems of the exotic and native iceplant taxa found in New Zealand. I begin by briefly outlining the influence of competition and facilitation on natural plant communities with reference to the role of facilitation in eco-restoration. I also give a few examples where exotic species have been found to facilitate native ones. Secondly, a neighbour removal experiment was conducted on coastal sand dunes with the main aim of studying the effects of Carpobrotus edulis on establishment of Spinifex sericeus at the foredune region. Finally, I compared the growth rates of the most widely distributed iceplant taxa in New Zealand in different substrates and the breeding systems of the exotic Carpobrotus.  Examples abound in literature of exotic plant species facilitating native ones especially in forestry. In the neighbour removal study, Carpobrotus edulis protected Spinifex seedlings against storm erosion, sandblasting and salt sprays while at the same time suppressing its leaf production. Suppression of Spinifex leaf production was more pronounced at top of the dune where stress elements is presumably more benign. There was no evidence of allelopathic suppression of Spinifex by C. edulis. Only Carpobrotus chilensis displayed some level of substrate preference by putting on relatively lower biomass in gravel. The exotic Carpobrotus spp. put on greater dry matter content than the native Disphyma australe and the Carpobrotus-x-Disphyma hybrid. The hybrid displayed a faster vegetative growth rate whereas D. australe allocated relatively more biomass to the roots than the shoot. Both Carpobrotus spp. are self compatible and highly capable of intrageneric and intergeneric hybridisation. Mass removal of the existing exotic iceplant stands from foredunes along high energy coasts is not advisable as they serve as useful stabilisers. The intergeneric hybrid is sexually sterile with sparsely spread stolons that could allow co-occurrence with other species and therefore is more suitable for foredune stabilisation. However, more research needs to be conducted on the ecology of the intergeneric hybrid.</p>


Genetika ◽  
2011 ◽  
Vol 43 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Aleksandar Lucic ◽  
Vasilije Isajev ◽  
Rade Cvjeticanin ◽  
Ljubinko Rakonjac ◽  
Marijana Novakovic ◽  
...  

The genetic-ecological variation of Scots pine (Pinus sylvestris L.) in Serbia was studied in the populations at five localities in western and south-western Serbia. Three groups of Scots pine (Pinus sylvestris L.) populations were differentiated based on genetic research (seed protein analysis) and plant community research. The first group consists of Scots pine populations on Sargan (FMU ?Sargan?) and on Tara (FMU ?Kaluderske Bare?), where the forests belong to the community of Scots pine and Austrian pine (Pinetum sylvestris-nigrae Pavlovic 1951). The second group covers the localities Stolovi (FMU ?Radocelo-Crepuljnik?) and Zlatar (FMU ?Zlatar I?), where the forests belong to the community of Scots pine and spruce (Piceo abietis-Pinetum sylvestris Stefanovic 1960). The third group comprises the Scots pine population on Pester (FMU ?Dubocica-Bare?) which belongs to the community of Scots pine with erica (Erico-Pinetum sylvestris Stefanovic 1963). Cluster analysis was performed on the basis of seed protein data and showed that there are three groups of Scots pine populations. The three populations coincide with plant communities. The community of Scots pine with erica (Erico-Pinetum sylvestris Stefanovic 1963) recorded on Pester at the locality ?Dubocica- Bare? in the area of FE ?Golija? Ivanjica, is a special Scots pine population displayed at the greatest distance from all other populations in the cluster analysis dendrogram.


2019 ◽  
Vol 116 (15) ◽  
pp. 7371-7376 ◽  
Author(s):  
Jenalle L. Eck ◽  
Simon M. Stump ◽  
Camille S. Delavaux ◽  
Scott A. Mangan ◽  
Liza S. Comita

Microbes are thought to maintain diversity in plant communities by specializing on particular species, but it is not known whether microbes that specialize within species (i.e., on genotypes) affect diversity or dynamics in plant communities. Here we show that soil microbes can specialize at the within-population level in a wild plant species, and that such specialization could promote species diversity and seed dispersal in plant communities. In a shadehouse experiment in Panama, we found that seedlings of the native tree species, Virola surinamensis (Myristicaceae), had reduced performance in the soil microbial community of their maternal tree compared with in the soil microbial community of a nonmaternal tree from the same population. Performance differences were unrelated to soil nutrients or to colonization by mycorrhizal fungi, suggesting that highly specialized pathogens were the mechanism reducing seedling performance in maternal soils. We then constructed a simulation model to explore the ecological and evolutionary consequences of genotype-specific pathogens in multispecies plant communities. Model results indicated that genotype-specific pathogens promote plant species coexistence—albeit less strongly than species-specific pathogens—and are most effective at maintaining species richness when genetic diversity is relatively low. Simulations also revealed that genotype-specific pathogens select for increased seed dispersal relative to species-specific pathogens, potentially helping to create seed dispersal landscapes that allow pathogens to more effectively promote diversity. Combined, our results reveal that soil microbes can specialize within wild plant populations, affecting seedling performance near conspecific adults and influencing plant community dynamics on ecological and evolutionary time scales.


1998 ◽  
Vol 20 (1) ◽  
pp. 119 ◽  
Author(s):  
B Fergusson ◽  
AJ Graham

The soil and plants at a 27.4 ha field site near Kalgoorlie, Western Australia, were surveyed and analysed with multivariate statistics. Cluster analysis identified four distinct plant communities at the study site. These were: Acacia acuminata shrubland Eucalyptus gvfithsii woodland Eucalyptus salrnonophloia woodland 'Ground Covers' - areas characterised by the presence of generalist herbs, low shrubs and weeds, and the absence of dominant upper storey species. Discriminant function analysis identified site elevation and soil exchangeable Ca as the primary environmental discriminants between the plant communities. Using these two variables, sample points were classified into one of the four plant communities. The two methods of classification matched well, with classification based on the two environmental variables providing an indication of which plant community would be most likely to establish in disturbed areas. This type of information can be important to revegetation programs in the region, guiding the use of appropriate plant species under different rehabilitation conditions. Key wcrds: environmental variables, plant communities, multivariate analysis, classification, revegetation


Author(s):  
Marju Prass ◽  
Satu Ramula ◽  
Miia Jauni ◽  
Heikki Setälä ◽  
D. Johan Kotze

AbstractThe ecological impacts of invasive species may change or accumulate with time since local invasion, potentially inducing further changes in communities and the abiotic environment. Yet, time since invasion is rarely considered when investigating the ecological impacts of invasive non-native species. To examine the effect of time since invasion on the ecological impacts of Lupinus polyphyllus, a perennial nitrogen-fixing herb, we surveyed vascular plant communities in the presence and absence of L. polyphyllus in young, intermediate, and old semi-natural grassland sites (ca. 5, 10, 15 years representing both time since lupine invasion and plant community age). We analyzed vascular plant community composition, vascular plant species richness, and the cover of various ecological plant groups and L. polyphyllus. In contrast to our hypotheses, we found no change in the mean cover of L. polyphyllus (about 35%) with time since local invasion, and an ordination did not suggest marked changes in plant community composition. L. polyphyllus was associated with lower species richness in invaded plant communities but this effect did not change with time since invasion. Invaded plant communities were also associated with lower occurrence of generalist, oligotrophic (low-nutrient-adapted) and copiotrophic (nutrient-demanding) species but no temporal dynamics were detected. We conclude that even the intermediate cover of L. polyphyllus can reduce plant species richness, but the ecological impact caused by this invader might not dramatically change or accumulate with time since invasion.


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