Plant species richness mediates the effects of vegetation structure, but not soil fertility, on insect gall richness in a savanna in Brazil

2017 ◽  
Vol 33 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Walter Santos de Araújo
Keyword(s):  
Organic Matter ◽  
Species Richness ◽  
Soil Organic Matter ◽  
Plant Height ◽  
Plant Species ◽  
Vegetation Structure ◽  
Plant Species Richness ◽  
Plant Abundance ◽  
Insect Galls ◽  
Insect Gall

Abstract:The present study aims to investigate the effects of vegetation structure (plant abundance and height) and soil characteristics (soil organic matter and macronutrients) on insect gall richness, and determine the extent to which these effects are mediated by the indirect effects of plant species richness. The study was performed in forty-nine 100-m2 savanna plots in Parque Nacional das Emas (Brazil) and sampled a total of 985 individual plants of 71 plant species and 97 insect gall morphotypes. Cecidomyiidae (Diptera) induced the most insect galls (38.1%), and the plant family Myrtaceae had the greatest richness of insect gall morphotypes (16). Path analysis of plant abundance, plant height, soil macronutrients, soil organic matter and plant species richness explained 73% of insect gall richness. The results show that soil macronutrient quantity has a direct positive effect on insect gall richness, whereas plant abundance and plant height had only indirect positive effects on insect gall richness via the increase in plant species richness. These findings showed that both plant-related and environment-related factors are important to induce insect gall richness in Neotropical savannas, and that plant species richness should be taken into account to determine the richness of insect galls.

scholarly journals Drivers of vascular plant species area relationships in British broadleaved woodlands and their effects on the species area curve

2020 ◽  
Author(s):  
Petra Guy ◽  
Simon Smart ◽  
Colin Prentice
Keyword(s):  
Organic Matter ◽  
Species Richness ◽  
Soil Organic Matter ◽  
Plant Species ◽  
Habitat Heterogeneity ◽  
Vascular Plant ◽  
Plant Species Richness ◽  
Riparian Zones ◽  
Natural Habitats ◽  
Species Area

SummaryThe loss of plant biodiversity in Great Britain is a major concern, with a fifth of species endangered or vulnerable according to the latest IUCN Red List. The Government’s 25 Year Plan for the environment aims to halt this loss and build new habitats, including new woodlands. To ensure that biodiversity loss is halted in existing woodlands and gain is maximised in new ones, we need to better understand which drivers have been most influential in controlling biodiversity. Here we focus on vascular plant species’ richness.Previous attempts to explain plant species richness have mainly focussed on alpha diversity in a consistent, fixed unit area. Here, we additionally undertake a novel analysis of the effects of environmental heterogeneity and abiotic factors on species-area relationships derived from 16 randomly placed quadrats in each of 103 semi-natural, broad-leaved woodlands across Britain. Species-area relationships were examined at two scales (4m2 to 200m2 and 200m2 to 3200m2) to explore the relationship between the drivers of species richness and the exponent z, of the canonical species-area curve, S = cAz. We also explore the use of a new metric ζr, based on zeta diversity to quantify heterogeneity. Zeta diversity quantifies the number of species shared between multiple combinations of plots.Habitat heterogeneity increased species richness, as did the proximity of the woodlands to surrounding natural habitats. Higher levels of soil organic matter and the progression of woodlands to later successional stages, decreased species richness. Richness was also seen to have a unimodal response to soil acidity with a peak around pH 6. At the smaller scale, heterogeneity elements in the woodland such as riparian zones or coppicing led to an increase in the value of the exponent of the species area curve. At the larger scale, species turnover led to an increase in the exponent of the curves while succession led to a decrease. At both scales, soil organic matter content had a negative effect. ζr was found to be a significant and important variable and to affect both species richness and the slope of the species accumulation curves at larger scales.SynthesisHabitat heterogeneity measures included the presence of coppicing, open areas such as rides and riparian zones and the difference between species assemblages in different plots in the woodland. Results suggest that to maximize vascular plant diversity, woodlands should be managed for heterogeneity. In addition, the increase in richness with exposure to surrounding natural habitats suggests that woodlands benefit from being embedded in more benign habitats and further, that land management surrounding woodlands has a clear role to play in supporting biodiversity within woodlands. This is an area were Agri-environment schemes have an important role.

scholarly journals Predicting Woody Plant Diversity as Key Component of Ecosystems

2019 ◽  
Vol 10 (1) ◽  
pp. 1-20
Author(s):  
Alexandra D. Solomou ◽  
Athanassios Sfougaris
Keyword(s):  
Organic Matter ◽  
Species Richness ◽  
Soil Organic Matter ◽  
Plant Species ◽  
Woody Plant ◽  
Plant Species Richness ◽  
Plant Litter ◽  
Woody Plant Species ◽  
Species Richness And Diversity ◽  
Olive Groves

The Mediterranean basin is a global hotspot of biodiversity. Woody plants are key components of ecosystems. This article explores the environmental impacts on woody plant species richness and diversity in maquis and abandoned olive groves in an important ecological area of central Greece. The results showed that woody plant species richness and diversity had increasing values in maquis compared to abandoned olive groves. According to Principal Component Analysis, woody plant species richness and diversity (Shannon diversity index) were positively correlated with soil organic matter, plant litter, N, P, K, slope and precipitation in maquis. Also, positive correlations among woody plant species richness and diversity, and soil organic matter, and slope were detected in abandoned olive groves. Conclusively, the present study is the first in the area and the results it will be utilized as a decision support tool for sustainability assessment of ecosystems with the help of the information systems.

scholarly journals Investigating the drivers of macro-fungal dark diversity using LiDAR

2020 ◽  
Author(s):  
Jose W. Valdez ◽  
Ane Kirstine Brunbjerg ◽  
Camilla Fløjgaard ◽  
Lars Dalby ◽  
Kevin K. Clausen ◽  
...  
Keyword(s):  
Species Richness ◽  
Soil Fertility ◽  
Plant Species ◽  
Vegetation Structure ◽  
Field Measurements ◽  
Plant Species Richness ◽  
Data Set ◽  
Management Plans ◽  
Suitable Site ◽  
Plant Data

AbstractDespite the important role of fungi for ecosystems, relatively little is known about the factors underlying the dynamics of their diversity. Moreover, studies do not typically consider their dark diversity: the absent species from an otherwise suitable site. Here, we examined the drivers of local fungal dark diversity in temperate woodland and open habitats using LiDAR and in-situ field measurements, combined with a systematically collected and geographically comprehensive (national) macro-fungi and plant data set. For the first time, we also estimated species pools of fungi by considering both plant and fungi co-occurrences. The most important LiDAR variables were amplitude and echo ratio, which are both thought to represent vegetation structure. These results suggest that the local fungal dark diversity is highest in tall dense forests like plantations and lowest in more open forests and open habitats with little woody vegetation. Plant species richness was the most important driver and negatively correlated with local fungal dark diversity. Soil fertility showed a positive relationship with dark diversity in open habitats. This may indicate that the local dark diversity of macro-fungi is highest in areas with a relatively high human impact (typically areas with low plant species richness and high soil fertility). Overall, this study brings novel insights into local macro-fungi dark diversity patterns, suggesting that a multitude of drivers related to both soil and vegetation act in concert to determine fungal dark diversity. Our results suggest that policymakers and conservation managers should consider plant species richness, soil fertility, and vegetation structure in future management plans for fungal communities.

Termite Foraging on Plants of a Brazilian Savanna: the Effects of Tree Height

Sociobiology ◽  
2018 ◽  
Vol 65 (1) ◽  
pp. 48 ◽  
Author(s):  
Geraldo Wilson Fernandes ◽  
Samuel L Murcia ◽  
Jean Carlos Santos ◽  
Og DeSouza ◽  
Reginaldo Constantino ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Plant Height ◽  
Plant Species ◽  
Host Species ◽  
Vegetation Structure ◽  
Basal Area ◽  
Tree Height ◽  
Tropical Environments ◽  
Cerrado Savanna

Termites play an important role as ecosystem engineers in many tropical environments, acting as herbivore-detritivore organisms and strongly influencing vegetation structure and composition by modifying soil properties, providing nutrients by recycling the organic matter, and direct feeding on plants, notably in the Cerrado (Savanna) of Brazil. To evaluate the intensity of termite foraging on Cerrado plants, we recorded plants higher than 25 cm, which exhibited termite activity along nine transects (2 x 50m), at the Estação Ecológica de Pirapitinga (EEP), in the State of Minas Gerais, Brazil. We recorded the height, basal area, and identified the species of each plant. Simultaneously, we used cellulose baits disposed at each 10 m along six transects of 100 m to sample termites in this area, which was protected from fire for at least 40 years. Twelve species of termites were recorded. Termite foraging on Cerrado plant species varied considerably and it was influenced by several factors including plant height and host species. Taller plants presented more termites than smaller plants, probably due to the amount of available resources (for nesting and feeding) for the termites.

scholarly journals Soil carbon and plant diversity distribution at the farm level in the savannah region of Northern Togo (West Africa)

2008 ◽  
Vol 5 (5) ◽  
pp. 4107-4127 ◽  
Author(s):  
M.-T. Sebastià ◽  
E. Marks ◽  
R. M. Poch
Keyword(s):  
Organic Matter ◽  
Species Richness ◽  
Soil Organic Matter ◽  
West Africa ◽  
Plant Species ◽  
Plant Diversity ◽  
Soil Degradation ◽  
Organic Matter Content ◽  
Matter Content ◽  
Vegetation Composition

Abstract. In western Africa, soil organic matter is a source of fertility for food provision and a tool for climate mitigation. In the Savannah region, strong soil degradation linked to an increase in population threatens organic matter conservation and agricultural yield. Soil degradation is also expected to impact biodiversity and, with it, increase the vulnerability of ecosystem goods and services, including the storage of soil organic carbon. Studies of land use, plant species composition and soil fertility were conducted for a conservation project at a demonstration farm in Northern Togo (West Africa), host to various management regimes. Results showed a low organic matter content of the surface soil horizons, often around 0.5%. The highest values were found in a sacred forest within the farm (2.2%). Among crops, rice had the highest soil organic matter, around 1%. In a survey of grasslands, pastures showed the highest organic matter content, with vegetation composition differing from grazed fallows and abandoned grasslands. Plant species richness showed a positive relationship with soil organic matter (R2adj=41.2%), but only by the end of the wet season, when species richness was also highest. Sampling date had a strong effect on vegetation composition. Results showed a strong influence of human activity on soil formation and distribution, and also on plant diversity. The soil characteristics found under the permanent forest suggest a high potential of the soils of the region for improvement of both agricultural yields and as a potential carbon sink relevant to global change policies.

Sign in / Sign up

Export Citation Format

Share Document