Effects of flood interruption on species richness, diversity and floristic composition of woody regeneration in the Upper Rhine alluvial hardwood forest

2001 ◽  
Vol 17 (4-5) ◽  
pp. 393-405 ◽  
Author(s):  
Anne-Frédérique Deiller ◽  
Jean-Michel N. Walter ◽  
Michèle Trémolières
Keyword(s):  
Species Richness ◽  
Floristic Composition ◽  
Hardwood Forest ◽  
Upper Rhine

Diversity metrics, species turnovers and nestedness of bird assemblages in a deep karst sinkhole

2017 ◽  
Vol 63 (2) ◽  
pp. 8-16 ◽  
Author(s):  
Corrado Battisti ◽  
Marco Giardini ◽  
Francesca Marini ◽  
Lorena Di Rocco ◽  
Giuseppe Dodaro ◽  
...  
Keyword(s):  
Species Richness ◽  
Random Distribution ◽  
Diversity Index ◽  
Species Turnover ◽  
Floristic Composition ◽  
Bird Assemblages ◽  
Β Diversity ◽  
Stick Model ◽  
Karst Sinkhole

We reported a study on breeding birds occurring inside an 80 m-deep karst sinkhole, with the characterization of the assemblages recorded along its semi-vertical slopes from the upper edge until the bottom. The internal sides of the sinkhole have been vertically subdivided in four belts about 20 m high. The highest belt (at the upper edge of the cenote) showed the highest values in mean number of bird detections, mean and normalized species richness, and Shannon diversity index. The averaged values of number of detections and species richness significantly differ among belts. Species turnover (Cody’s β-diversity) was maximum between the highest belts. Whittaker plots showed a marked difference among assemblages shaping from broken-stick model to geometric series, and explicited a spatial progressive stress with a disruption in evenness towards the deepest belts. Bird assemblages evidenced a nested subset structure with deeper belts containing successive subsets of the species occurring in the upper belts. We hypothesize that, at least during the daytime in breeding season, the observed non-random distribution of species along the vertical stratification is likely due to (i) the progressive simplification both of the floristic composition and vegetation structure, and (ii) the paucity of sunlight as resources from the upper edge to the inner side of the cenote.

scholarly journals Effect of fire on a monodominant floating mat of Cyperus giganteus Vahl in a neotropical wetland

2015 ◽  
Vol 75 (1) ◽  
pp. 114-124 ◽  
Author(s):  
M. Rocha ◽  
CC. Santos Júnior ◽  
GA. Damasceno-Júnior ◽  
VJ. Pott ◽  
A. Pott
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Annual Variation ◽  
Floristic Composition ◽  
Large Area ◽  
Characteristic Species ◽  
Cyperus Giganteus ◽  
Pantanal Wetland ◽  
Floating Mat ◽  
Adult Plants

The rhizomatous Cyperus giganteus, abundant in the Pantanal wetland, can dominate extense floodable areas as monodominant communities. The Jacadigo lake has a large area of C. giganteus, where we performed an evaluation on community structure during two months in 2010, before it was hit by a wildfire which top-killed the vegetation, compared to ten months post-fire. We utilized 40 plots of 1m × 1m, along permanent trails, assessing two strata: the upper, near the inflorescence of adult plants, and the lower, close to the water level. Our results show that fire does not affect dominance of C. giganteus, as it maintained the same cover as before fire; species richness is not much altered either - 28 before fire and 34 thereafter. Fire changed the floristic composition, due to the annual variation of species and the ability of some plants to colonize gaps and to regrow after fire from underground organs and seeds. The stratification of the vegetation with characteristic species of upper and lower strata was similar after fire.

scholarly journals Floristic composition of the Montane Forest in the Almadina-Barro Preto axis, Southern Bahia, Brazil

2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Macielle Macedo Coelho ◽  
André Márcio Amorim
Keyword(s):  
Species Richness ◽  
Tropical Forests ◽  
Atlantic Forest ◽  
Floristic Composition ◽  
Woody Species ◽  
Life Forms ◽  
Montane Forest ◽  
Forest Remnants ◽  
Southern Bahia ◽  
Arboreal Habit

The aim of this study is to survey the angiosperms of two montane forest remnants in the southern Bahia, Brazil: Corcovado (SCO) and Pedra Lascada (SPL). Both fragments are located in the municipality of Almadina and Barro Preto, respectively, and are 18 km distant from each other. We sampled 899 species of angiosperms distributed in 437 genera and 116 families. The SCO was the richest area with 678 species, distributed in 367 genera and 100 families. SPL showed 466 species in 269 genera and 88 families. The percentage of species identified was 85.8% and of this total, 37.7% are endemic to the Atlantic Forest, 11.2% are endemic to southern Bahia and northern Espírito Santo and 7% are disjunct between the Atlantic Forest and Amazon. The remaining percentages (44.3%) were of species widely distributed. The richest families in the two areas were Orchidaceae (10%), Rubiaceae (7%), Bromeliaceae (5.5%), Melastomataceae (4.2%) and Poaceae (4%). The richest genera were Psychotria (2%),Piper (1.8%), Ocotea (1.6%),Vriesea (1.5%) and Peperomia (1.4%). More than half of the recorded species showed non-arboreal habit, regarding life forms documented. That comes against the assertion that many authors in the tropical forests, where species richness in angiosperms is expected for non-woody species, especially in montane forests. Twelve species have been identified as new, but seven others already described from collections previously obtained in these two areas. Orchidaceae, Rubiaceae, Poaceae and Bromeliaceae showed significant richness in this study these families are commonly reported as the richest in other inventories in the Atlantic Forest in southern Bahia reinforcing their importance to the regional flora. The high levels of richness, endemism, and the growing numbers of new taxonomic discoveries from the SPL and SCO sites indicate the biological importance of these two forest remnants. The implementation of parks or other protected environmental reserves would be essential to the conservation of its species.

Floristic and structural contrasts between natural savannas and anthropogenic pastures in a tropical dry landscape

2007 ◽  
Vol 29 (2) ◽  
pp. 181 ◽  
Author(s):  
L. I. López-Olmedo ◽  
J. A. Meave ◽  
E. A. Pérez-García
Keyword(s):  
Species Richness ◽  
Floristic Composition ◽  
Southern Mexico ◽  
Deterioration Process ◽  
Isthmus Of Tehuantepec ◽  
Dominance Indices ◽  
Vegetation Samples ◽  
Severe Deterioration ◽  
Biological Differentiation ◽  
Sørensen Index

The magnitude of the biological differentiation between natural savannas and pastures (anthropogenic grasslands) coexisting in a single landscape, in terms of their floristic composition and community structure, was studied in the Nizanda region, Isthmus of Tehuantepec, Oaxaca State, southern Mexico. Vegetation samples of 15 m2 each were taken at 20 savanna and 11 pasture sites. Cover- and species richness-based diversity and dominance indices were calculated. Geomorphological and edaphic characteristics were also compared. Savannas generally occurred in hill summits with very shallow and stony, discontinuous and acidic soils; contrastingly, pastures were located in piedmonts and floodplains, with more neutral and less stony soils. Savanna sites differed from pasture sites in species richness and Shannon diversity. They did not differ in Simpson dominance index, but the identity of the dominant species was different in each community: Trachypogon spicatus (L.f.) Kuntze in savanna and Megathyrsus maximus (Jacq.) B.K.Simon et S.W.L.Jacobs in pasture. A low species-level similarity (Sørensen Index) was observed between them (8.2%), and genus-level similarity was only slightly higher (27.1%). The magnitude of the biological differentiation in both community floristics and structure between these two grass-dominated communities was larger than anticipated. Current management of savannas as pasture lands may potentially trigger a severe deterioration process involving both the landscape and its plant components.

scholarly journals Liana species composition differs, in spite of trait similarities, in two adjacent forest types in Central Brazil

2017 ◽  
Vol 65 (3) ◽  
pp. 1215 ◽  
Author(s):  
Ana Carolina Souza Brito ◽  
Alexandre Ferraro ◽  
Robyn J. Burnham ◽  
Ângela Lúcia Bagnatori Sartori ◽  
Vivian Almeida Assunção
Keyword(s):  
Species Richness ◽  
Deciduous Forest ◽  
Morphological Characteristics ◽  
Floristic Composition ◽  
Dry Forest ◽  
Forest Fragments ◽  
Vegetation Types ◽  
Forest Types ◽  
Climbing Plants ◽  
Dispersal Syndromes

In the Parana basin, the Serra de Maracaju juxtaposes the Seasonal Dry Forest and the cerradão (a phytophysiognomy of Cerrado), two distinct vegetation types that differ in canopy height, tree density, and composition of the understory. In the same way, these differences may be reflected in the composition of climbing plant species found in these two forest types. Thus, in this study we compared the climbing species in two forest fragments of Serra de Maracaju to understand: (1) Are species richness and floristic composition of climbing plants similar in cerradão and seasonal deciduous forest?, (2) What degree of floristic compositional difference exists between the two vegetation types?, (3) Do the two vegetation types differ significantly in climbing mechanisms, life forms, and dispersal syndromes represented among climbing species? For this, we established and sampled four plots per forest type over 24 months. Species were identified and each one classified, based on three discrete traits. Proportional differences were analyzed using chi-square tests. Our results showed that species richness and floristic composition of climbing plants in the cerradão and the seasonal deciduous forest were not similar. Climber species richness in cerradão was 37 while in the seasonal deciduous forest it was 31; they share only 13 species. Four families, Dioscoreaceae, Fabaceae, Malpighiaceae, and Sapindaceae, included over 60% of the climbing species. The morphological traits most common in both forest types were herbaceous life form, apical twining mechanism, and wind dispersal. Dioscoreaceae was found to be the dominant family, but is the first time to be reported for this condition in Brazil. Bignoniaceae and Passifloraceae ocurred only in the cerradão, and Asteraceae and Combretaceae in the seasonal deciduous forest; some species were found exclusively in a type of forest. Floristic composition of the cerradão and seasonal deciduous forest fragments were substantially different, in spite of physical proximity. However, their climbing species are not statistically distinct in morphological characteristics, possibly due to uniform climatic conditions and the similarity of species because of a shared ancestry (similar families).

scholarly journals Weeds Associated with Banana Crops in Magdalena Department, Colombia

2020 ◽  
Vol 38 ◽  
Author(s):  
I. QUINTERO-PERTÚZ ◽  
E. CARBONÓ-DELAHOZ ◽  
A. JARMA-OROZCO
Keyword(s):  
Species Richness ◽  
Native Species ◽  
Floristic Composition ◽  
Common Species ◽  
Cycle Growth ◽  
The Family ◽  
Agroecological Zones ◽  
Pattern Comparison ◽  
Representative Farms ◽  
Banana Crops

ABSTRACT: This study was conducted to determine the richness and composition of weed communities associated with banana plantations in Magdalena department, Colombia. Between September 2016 and May 2017, a total of 164 hectares were assessed over four agroecological zones (Alta, Media, Baja and Norte); in each zone, three representative farms were selected where, through zigzag paths, botanical collections were made in cultivated lots. Information on life cycle, growth habit and origin of each species was included. The floristic composition was represented by 204 species distributed among 143 genera and 54 families. Poaceae, with 31 species, was the family with the highest species richness, followed by Fabaceae (12) and Asteraceae (11). From the total species recorded, 113 are perennial (55%) and 91 are annual (45%); 141 species are herbaceous (68%), 38 are climbers (20%), and 25 are arboreal or shrubby (12%). Native species predominate over introduced species. The species richness does not differ significantly between the sampling zones, but the weed community composition does. The presence of common species reported as important weeds worldwide was recorded in the four zones. However, some species were recorded in only one of the zones, generating a differential composition pattern. Comparison with local inventories showed changes in the composition of the weed complex over time. The presence of various species not previously considered weeds in the banana crops of this region is highlighted.

A comparison of Mopaneveld vegetation in South Africa, Namibia and Zimbabwe

Bothalia ◽  
2003 ◽  
Vol 33 (1) ◽  
pp. 121-134 ◽  
Author(s):  
F. Siebert ◽  
G. J. Bredenkamp ◽  
S. J. Siebert
Keyword(s):  
South Africa ◽  
Species Richness ◽  
Plant Communities ◽  
Environmental Gradients ◽  
Floristic Composition ◽  
Alpha Diversity ◽  
Environmental Data ◽  
Annual Rainfall ◽  
Vegetation Types ◽  
Rainfall Events

Data from fifteen phytosociological studies were merged and classified to describe and compare the vegetation of geo­graphically separated and climatically different Mopanev eld types in South Africa. Namibia and Zimbabw e. Seven v egetation types and ten major plant communities were identified using TW INSPAN. Vegetation types were separated according to geo­graphical regions. There were significant floristic affinities even though there w ere geological and climatic differences between the regions. Plant communities were described according to vegetation structure, habitat and floristic composition. Although environmental data were not adequate for a detailed ordination. DECORANA reflected the distribution of vegetation types and major plant communities along environmental gradients. Limitations of large phytosociological syntheses were also addressed. Species richness (alpha diversity) was calculated for each geographical region. The Musina (Messina) region north of the Soutpansberg. South Africa, has the highest species richness, and Kaokoland. Namibia, the lowest Due to irregular annual rainfall patterns in semi-arid Mopaneveld, it is suggested that variance in species richness is associated with temporal vegeta­tion states induced by rainfall events. Species richness of Mopaneveld was further compared w ith other sav anna types.

Impact of sheep grazing on the soil seed bank of a managed ephemeral wetland: implications for management

2007 ◽  
Vol 55 (2) ◽  
pp. 103 ◽  
Author(s):  
Jason Nicol ◽  
Sally Muston ◽  
Paula D'Santos ◽  
Bernard McCarthy ◽  
Sylvia Zukowski
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Floristic Composition ◽  
Seed Banks ◽  
Water Level Fluctuations ◽  
Typha Domingensis ◽  
Ephemeral Wetland ◽  
Cuscuta Campestris

The seed bank is an important mechanism for the persistence of species in ephemeral wetlands, but grazing by domestic stock may change the seed bank and in turn the capacity of the system to recover from disturbance. The sediments of two areas in Thegoa Lagoon (Murray–Darling Basin), one area grazed by sheep when dry and the other ungrazed, were examined. The objective of the study was to determine whether and how the (1) germinable seed bank and (2) final plant communities differ between the grazed and ungrazed areas. The seed banks were subjected to one of the following three water depths: 5 cm above the surface of the water, 5 cm below the surface and 50 cm below the surface. The composition of the seed bank was determined by using the seedling-emergence technique for 12 weeks, with seedlings removed every 2 weeks. The final plant communities were determined at 12 weeks without removing seedlings. The seed bank from the grazed area had a significantly lower seed density (5600 ± 593 seeds m–2) and species richness (7 species) than the ungrazed area (37 683 ± 4492 seeds m–2, 16 species) (ANOVA: F1, 10 = 50.16, P < 0.0001). The floristic composition of the seed bank was also significantly different between the areas (NPMANOVA: F1, 10 = 15.44, P = 0.0032). Glinus lotoides was in higher abundance in the grazed area and Alternanthera denticulata, Persicaria lapathifolium, Polygonum plebium, Typha domingensis and Centipeda cunninghamii in the ungrazed area. Similarly, the final communities derived from the grazed and ungrazed areas were significantly different from each other (NPMANOVA: F1, 10 = 15.53, P = 0.0032). Greater numbers of Centipeda cunninghamii were present in the community from the grazed area and Alternanthera denticulata and Cuscuta campestris were present in larger numbers in the community from the ungrazed area. Water depth also had an impact on germination; no germination occurred in seed banks flooded to 50 cm and one Typha domingensis seedling was observed in a sample flooded to 5 cm. These results showed that grazing reduces the density and species richness of the seed bank and in turn changes the plant communities derived from the seed bank; however, if grazing is removed pest plants such as Cuscuta campestris may require control. In addition, managed drawdown or water-level fluctuations are important in exposing wetland sediments and allowing for species to recruit from the seed bank.

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