Are productivity and richness related consistently after different crops in the Neotropics?

Botany ◽  
2009 ◽  
Vol 87 (4) ◽  
pp. 357-362 ◽  
Author(s):  
Randall W. Myster
Keyword(s):  
Species Richness ◽  
Saccharum Officinarum ◽  
Root Competition ◽  
Permanent Plots ◽  
Tree Seedlings ◽  
Musa Sp ◽  
Neotropical Tree ◽  
Setaria Sphacelata ◽  
Set Up ◽  
Unimodal Pattern

To better understand the relationship between productivity and species richness after disturbance in the Neotropics, I tested two hypotheses using tree stem data collected in permanent plots set up after abandonment from agriculture. I found that (i) species richness had a significant positive relationship with productivity, where the slopes of the regression lines decreased over time for all fields taken together suggested the early upswing, leveling off, and later downswing of a unimodal curve; and (ii) this unimodal pattern held true both in the recovering sugarcane ( Saccharum officinarum  L.) and in the recovering banana ( Musa sp.) plantations. There was a delay, however, in the development of the unimodal pattern in the seeded pasture, perhaps due to root competition between the residual tussock grass ( Setaria sphacelata (Schumacher) Moss) and Neotropical tree seedlings. Taken together, the results imply that a unimodal model between productivity and species richness after agriculture may be independent of specific field conditions such as past crop and, therefore, represent a more universal ecological concept.

scholarly journals Shift in the Spatio-Temporal Natural Fruiting of Boletes in West African Woodlands: the Key Role of the Soil Moisture

2020 ◽  
Author(s):  
Akotchayé Sylvestre Badou ◽  
Roel D. Houdanon ◽  
Kassim I. Tchan ◽  
D.M.T. Apollon Hègbè ◽  
Nourou Soulemane Yorou
Keyword(s):  
Species Richness ◽  
Soil Moisture ◽  
Ectomycorrhizal Fungi ◽  
Linear Models ◽  
Positive Influence ◽  
Permanent Plots ◽  
Data Logger ◽  
Fresh Biomass ◽  
Natural Production ◽  
Spatio Temporal

Abstract Background: The ectomycorrhizal fungi display strong fluctuations during the mycological season. However, how abiotic parameters affect the fruiting sequences of ectomycorrhizal fungi and also the direction and extent of this effect are not yet tapped adequately. The present study seeks to assess the microclimate effect on the natural production of boletes. Nine permanent plots of 2500 m2 (50m x 50m) split into 25 subplots of 100 m2 (10m x 10m) were installed in three different vegetation dominated respectively by Isoberlinia doka, Isoberlinia tomentosa and Uapaca togoensis. Microclimatic parameters were recorded each 30 minutes throughout by mean of a Micro Station Data Logger - H21-002 the mycological seasons. Each plot was surveyed twice a week (from May to October) over three years (2015, 2016 and 2017) to record the presence/absence of fruit bodies and fresh biomass of boletes. To evaluate the effect of time and microclimate variables on natural production, we used mixed effects and generalized linear models using R version 3.5.3. Results: In total, during the three years (2015, 2016 and 2017), we recorded 14 species of boletes. Species richness does not change over time (P > 0.05). In addition, fresh biomass varies within years and vegetation (P < 0.05). The combination of year and month of collection has a significant effect on the number of fruit bodies (P < 0.05). Only the soil moisture has a significant positive influence on the species richness of boletes (P > 0.05). Conclusions: When the soil moisture decreases by four units, the number of fruit bodies of ectomycorrhizal fungi is significantly reduced by one unit. Therefore, above 0.25 m3 / m3 and below 0.05 m3 / m3 there is a decrease in the number of fruit bodies.

scholarly journals Effects of Malaise trap spacing on species richness and composition of terrestrial arthropod bulk samples

2020 ◽  
Author(s):  
D Steinke ◽  
TWA Braukmann ◽  
L Manerus ◽  
A Woodhouse ◽  
V Elbrecht
Keyword(s):  
Species Richness ◽  
Field Experiments ◽  
Collection Efficiency ◽  
Malaise Trap ◽  
Number Of Factors ◽  
Large Numbers ◽  
Set Up ◽  
Taxonomic Groups ◽  
A Site ◽  
Malaise Traps

AbstractThe Malaise trap has gained popularity for assessing diverse terrestrial arthropod communities because it collects large samples with modest effort. A number of factors that influence collection efficiency, placement being one of them. For instance, when designing larger biotic surveys using arrays of Malaise traps we need to know the optimal distance between individual traps that maximises observable species richness and community composition. We examined the influence of spacing between Malaise traps by metabarcoding samples from two field experiments at a site in Waterloo, Ontario, Canada. For one experiment, we used two trap pairs deployed at weekly increasing distance (3m increments from 3 to 27 m). The second experiment involved a total of 10 traps set up in a row at 3m distance intervals for three consecutive weeks.Results show that community similarity of samples decreases over distance between traps. The amount of species shared between trap pairs shows drops considerably at about 15m trap-to-trap distance. This change can be observed across all major taxonomic groups and for two different habitat types (grassland and forest). Large numbers of OTUs found only once within samples cause rather large dissimilarity between distance pairs even at close proximity. This could be caused by a large number of transient species from adjacent habitat which arrive at the trap through passive transport, as well as capture of rare taxa, which end up in different traps by chance.

scholarly journals Seed dispersal increases local species richness and reduces spatial turnover of tropical tree seedlings

2017 ◽  
Vol 114 (40) ◽  
pp. 10689-10694 ◽  
Author(s):  
Elizabeth M. Wandrag ◽  
Amy E. Dunham ◽  
Richard P. Duncan ◽  
Haldre S. Rogers
Keyword(s):  
Species Richness ◽  
Seed Dispersal ◽  
Species Turnover ◽  
Spatial Diversity ◽  
Forest Composition ◽  
Tree Seedlings ◽  
Regional Patterns ◽  
Local Species Richness ◽  
Seed Dispersers ◽  
Open Question

Dispersal is thought to be a key process underlying the high spatial diversity of tropical forests. Just how important dispersal is in structuring plant communities is nevertheless an open question because it is very difficult to isolate dispersal from other processes, and thereby measure its effect. Using a unique situation, the loss of vertebrate seed dispersers on the island of Guam and their presence on the neighboring islands of Saipan and Rota, we quantify the contribution of vertebrate seed dispersal to spatial patterns of diversity of tree seedlings in treefall gaps. The presence of vertebrate seed dispersers approximately doubled seedling species richness within canopy gaps and halved species turnover among gaps. Our study demonstrates that dispersal plays a key role in maintaining local and regional patterns of diversity, and highlights the potential for ongoing declines in vertebrate seed dispersers to profoundly alter tropical forest composition.

The Role of Fallen Logs in the Regeneration of Tree Species in Tasmanian Mixed Forest

1999 ◽  
Vol 47 (5) ◽  
pp. 745 ◽  
Author(s):  
J. B. Kirkpatrick ◽  
H. J. A. McKenny
Keyword(s):  
Bulk Density ◽  
Tree Species ◽  
Substrate Surface ◽  
Mixed Forest ◽  
Canopy Cover ◽  
Root Competition ◽  
Tree Seedlings ◽  
Establishment Success ◽  
Moss Cover ◽  
Litter Cover

This study was designed to determine whether fallen logs were a more favourable habitat for tree species establishment than soil in moist eucalypt forest in Tasmania, whether establishment success on logs varied between two forests in contrasting environments, and whether surface and substrate qualities and light conditions were associated with establishment success. Data on tree and shrub species densities and heights by species, moss cover, litter cover, Blechnum wattsii cover, canopy cover, bulk density of the substrate, and substrate surface pH, nitrogen content and phosphorus content were obtained from paired soil and log quadrats. Tree seedlings were found to be significantly more abundant on fallen logs than on adjacent ground at both sites, with the differences being greater at the moister Tahune site than at Mount Field. At Tahune, logs significantly differed from adjacent soil in canopy cover, litter cover, moss cover Blechnum wattsii cover, pH and slope. At Mount Field, there were significant differences between logs and soil in litter cover, moss cover, pH, bulk density and nitrogen. Litter cover may be critical in explaining the superior establishment of trees on logs rather than soil in Tasmanian mixed forest, although the possible impacts of variations in bioturbation and root competition require further research.

scholarly journals Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

2014 ◽  
Vol 11 (19) ◽  
pp. 5521-5537 ◽  
Author(s):  
B. Magnússon ◽  
S. H. Magnússon ◽  
E. Ólafsson ◽  
B. D. Sigurdsson
Keyword(s):  
Species Richness ◽  
Plant Biomass ◽  
Vascular Plant ◽  
Plant Cover ◽  
Soil Formation ◽  
Plant Succession ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Nutrient Input ◽  
Species Richness And Diversity

Abstract. Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca/Agrostis/Ranunculus). We forecast that, with continued erosion of Surtsey, loss of habitats and increasing impact from seabirds a lush, species-poor grassland will develop and persist, as on the old neighbouring islands.

scholarly journals Changes in plant diversity in a water-limited and isolated high-mountain range (Sierra Nevada, Spain)

Alpine Botany ◽  
2021 ◽  
Author(s):  
Andrea Lamprecht ◽  
Harald Pauli ◽  
Maria Rosa Fernández Calzado ◽  
Juan Lorite ◽  
Joaquín Molero Mesa ◽  
...  
Keyword(s):  
Species Richness ◽  
Snow Cover ◽  
Sierra Nevada ◽  
Plant Diversity ◽  
Endemic Species ◽  
Vascular Plant ◽  
Climate Change Impacts ◽  
Permanent Plots ◽  
High Mountain ◽  
Mountain Range

AbstractClimate change impacts are of a particular concern in small mountain ranges, where cold-adapted plant species have their optimum zone in the upper bioclimatic belts. This is commonly the case in Mediterranean mountains, which often harbour high numbers of endemic species, enhancing the risk of biodiversity losses. This study deals with shifts in vascular plant diversity in the upper zones of the Sierra Nevada, Spain, in relation with climatic parameters during the past two decades. We used vegetation data from permanent plots of three surveys of two GLORIA study regions, spanning a period of 18 years (2001–2019); ERA5 temperature and precipitation data; and snow cover durations, derived from on-site soil temperature data. Relationships between diversity patterns and climate factors were analysed using GLMMs. Species richness showed a decline between 2001 and 2008, and increased thereafter. Species cover increased slightly but significantly, although not for endemic species. While endemics underwent cover losses proportional to non-endemics, more widespread shrub species increased. Precipitation tended to increase during the last decade, after a downward trend since 1960. Precipitation was positively related to species richness, colonisation events, and cover, and negatively to disappearance events. Longer snow cover duration and rising temperatures were also related to increasing species numbers, but not to cover changes. The rapid biotic responses of Mediterranean alpine plants indicate a tight synchronisation with climate fluctuations, especially with water availability. Thus, it rather confirms concerns about biodiversity losses, if projections of increasing temperature in combination with decreasing precipitation hold true.

scholarly journals Keanekaragaman dan Kelimpahan Belalang dan Kerabatnya (Orthoptera) pada Dua Ekosistem Pegunungan di Taman Nasional Gunung Halimun-Salak

2015 ◽  
Vol 7 (2) ◽  
pp. 100
Author(s):  
NETY VIRGO ERAWATI ◽  
SIH KAHONO
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
National Park ◽  
Diversity Index ◽  
Sampling Site ◽  
Similarity Index ◽  
Line Transect ◽  
Light Traps ◽  
Set Up ◽  
Sweep Net

A study on diversity and abundance of grasshopper and its relatives (Orthoptera) was conducted at two mountainous rainforest ecosystems (Mounts Kendeng and Botol) of Gunung Halimun-Salak National Park. A hundred meters of a line transect was used to sample and set up several insect traps (yellow pan, malaise, pit fall, bait pit fall, sweep net, and light traps), and insect sweepings as well. The light traps were set up at about fifty meters distance from the end of the sampling sites. A total individual collected by traps was combined on every comparable sampling site. Total individuals of the Orthoptera captured were 414; consisted of 25 species of 9 families. Both species diversity and number of families were higher at Mount Kendeng rather than Mount Botol. Number of species of each family usually similar except on family of Grillidae was much higher at Mount Kendeng. Species belong to Phasmidae was not recorded at Mount Kendeng, while species belong to both families of Gryllotalpidae and Tettigonidae were not captured at Mount Botol as well. Overal there was a difference in the species richness at each between. Shannon Diversity Index (H’) and evenness (E) were higher at Mount Kendeng (2.44 and 0.81) rather than Mount Botol (1.80 and 0.66). Similarity Index of Jaccard (Cj) and Sorenson (Cn) of both localities were similar (0.40 and 0.32). Herbivores were most dominant at both localities (Phasmidae, Tetrigidae, Acrididae, Gryllidae, dan Gryllotalpidae), followed by omnivores (Blattidae), scavenger (Gryllacrididae), and predator (Mantidae).

scholarly journals Floristic composition and similarity of 15 hectares in Central Amazon, Brazil

2018 ◽  
pp. 1927-1938
Author(s):  
Kátia Emidio da Silva ◽  
Sebastião Venancio Martins ◽  
Carlos Antonio Alvares Soares Ribeiro ◽  
Nerilson Terra Santos ◽  
Celso Paulo De Azevedo ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Rare Species ◽  
Diversity Index ◽  
Mantel Test ◽  
Permanent Plots ◽  
Terra Firme ◽  
Floristic Similarity ◽  
Forest Diversity ◽  
Number Of Individuals

The Amazon region is one of the most diverse areas in the world. Research on high tropical forest diversity brings up relevant contributions to understand the mechanisms that result and support such diversity. In the present study we describe the species composition and diversity of 15 one-ha plots in the Amazonian terra firme dense forest in Brazil, and compare the floristic similarity of these plots with other nine one-ha plots. The 15 plots studied were randomly selected from permanent plots at the Embrapa Experimental site, Amazonas State in 2005. The diversity was analysed by using species richness and Shannon’s index, and by applying the Sorensen’s index for similarity and unweighted pair-group average (UPGMA) as clustering method. Mantel test was performed to study whether the differences in species composition between sites could be explained by the geographic distance between them. Overall, we identified 8 771 individuals, 264 species and 51 plant families. Most of the species were concentrated in few families and few had large number of individuals. Families presenting the highest species richness were Fabaceae (Faboideae: 22spp., Mimosoideae: 22spp.), Sapotaceae: 22spp., Lecythidaceae: 15 and Lauraceae: 13. Burseraceae had the largest number of individuals with 11.8% of the total. The ten most abundant species were: Protium hebetatum (1 037 individuals), Eschweilera coriacea (471), Licania oblongifolia (310), Pouteria minima (293), Ocotea cernua (258), Scleronema micranthum (197), Eschweilera collina (176), Licania apelata (172), Naucleopsis caloneura (170) and Psidium araca (152), which represented 36.5% of all individuals. Approximately 49% of species had up to ten individuals and 13% appeared only once in all sampled plots, showing a large occurrence of rare species. Our study area is on a forest presenting a high tree species diversity with Shannon’s diversity index of 4.49. The dendrogram showed two groups of plots with low similarity between them (less than 0.25), and the closer the plots were one to another, more similar in species composition (Mantel R=0.3627, p<0.01). The 15 plots in our study area share more than 50% of their species composition and represent the group of plots that have the shortest distance between each other. Overall, our results highlight the high local and regional heterogeneity of environments in terra firme forests, and the high occurrence of rare species, which should be considered in management and conservation programs in the Amazon rainforest, in order to maintain its structure on the long run.

scholarly journals Recent global changes have decoupled species richness from specialization patterns in North American birds

2019 ◽  
Author(s):  
Anne Mimet ◽  
Robert Buitenwerf ◽  
Brody Sandel ◽  
Jens-Christian Svenning ◽  
Signe Normand
Keyword(s):  
Land Use ◽  
Species Richness ◽  
North American ◽  
Temporal Change ◽  
Temporal Changes ◽  
Global Changes ◽  
Spatio Temporal ◽  
The Relationship ◽  
Unimodal Pattern ◽  
Over Time

AbstractAimTheory suggests that increasing productivity and climate stability toward the tropics can explain the latitudinal richness gradient by favouring specialization. A positive relationship between species richness and specialization should thus emerge as a fundamental biogeographic pattern. However, land use and climate change disproportionally increase the local extirpation risk for specialists, potentially impacting this pattern. Here, we empirically quantify the richness-specialization prediction and test how 50 years of climate and land use change has affected the richness-specialization relationship.LocationUSATime period1966-2015Major taxa studiedBirdsMethodsWe used the North American breeding bird survey to quantify bird community richness and specialization to habitat and climate. We assess i) temporal change in the slope of the richness-specialization relationship, using a Generalized Mixed Model; ii) temporal change in spatial covariation of richness and specialization as driven by local environmental conditions, using Generalized Additive Models; and iii) land use, climate and topographic drivers of the spatio-temporal changes in the relationship, using a multivariate method.ResultsWe found evidence for a positive richness-specialization relationship in bird communities. However, the slope of the relationship declined strongly over time. Richness spatially covaried with specialization following a unimodal pattern. The peak of the unimodal pattern shifted toward less specialized communities over time. These temporal changes were associated with precipitation change, decreasing temperature stability and land use.Main conclusionsRecent climate and land use changes induced two antagonist types of community responses. In human-dominated areas, the decoupling of richness and specialization drove a general biotic homogenization trend. In human-preserved areas under increasing climate harshness, specialization increased while richness decreased in a “specialization” trend. Our results offer new support for specialization as a key driver of macroecological diversity patterns, and show that global changes are erasing this fundamental macroecological pattern.BiosketchAnne Mimet is a postdoctoral researcher interested in the understanding of human impacts on biodiversity through land use and climate changes, at various spatio-temporal scales. She is interested in embracing the complexity of socio-ecological systems, and in the understanding of biodiversity trends in a human-dominated world in the context of the general theories of ecology.

scholarly journals How do plant communities and flower visitors relate? A case study of semi-natural xerothermic grasslands

2013 ◽  
Vol 82 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Damian Chmura ◽  
Paweł Adamski ◽  
Zygmunt Denisiuk
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Communities ◽  
Correspondence Analysis ◽  
Positive Relationship ◽  
Detrended Correspondence Analysis ◽  
Permanent Plots ◽  
Moisture Index ◽  
Rarefaction Analysis ◽  
Flower Visitors

<p>The paper examines the relationships between the species composition of flower visitors and plants in the semi-natural xerothermic grasslands in southern and central Poland. Thirty 10 × 10 m permanent plots were laid out in total, mainly in nature reserves. The vegetation units studied were classified according to the Braun-Blanquet system; these were phytocoenoses of the <em>Festuco-Brometea</em> classes <em>Inuletum ensifoliae</em>, <em>Adonido-Brachypodietum pinnati</em> and the transitional plant community. Entomological research was performed using the Pollard method within the same plots. A particular site was visited only once and different sites were studied between April and August 2008. We applied, among others, co-correspondence-analysis Co-CA, detrended correspondence analysis (DCA) and redundancy analysis (RDA) to investigate the co-occurrence patterns of plants and flower visitors and their biotopic requirements. We found that the species composition of flower visitors cannot be predicted by floristic composition when the duration of the study is restricted to one day (but under similar weather conditions); however, there is a positive relationship between the species richness of insects and plants and a positive relationship between the number of plant species and the abundance of flower visitors. The Ellenberg moisture index and the cover of meadow species significantly explained the species composition of insects. The three various vegetation units and five dominant xerothermic species, i.e. <em>Adonis vernalis</em>, <em>Anemone sylvestris</em>, <em>Inula ensifolia</em>, <em>Linum hirsutum</em> and <em>Carlina onopordifolia</em> that were studied across time differed in the species richness of insects. Our results demonstrate that possible patterns in the species composition and the assembly rules of flower visitors are not apparent when the Pollard method is applied. Based on the data obtained using this method, the flower visiting assemblages seem not to be driven by competition and they primarily show a tendency to co-occur which can be an artifact. A plant-focused method that included a rarefaction analysis yielded more insightful results and shed more light on the differences between the dominant plants that shape the physiognomy of plant communities in a possible pollination specialization.</p>

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