Grazing Impact on Vegetation Structure and Plant Species Richness in an Old-Field Succession of the Venezuelan Páramos

Author(s):  
Lina Sarmiento
2017 ◽  
Vol 33 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Walter Santos de Araújo

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.


2020 ◽  
Author(s):  
Jose W. Valdez ◽  
Ane Kirstine Brunbjerg ◽  
Camilla Fløjgaard ◽  
Lars Dalby ◽  
Kevin K. Clausen ◽  
...  

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.


2022 ◽  
Vol 144 ◽  
pp. 332-338
Author(s):  
Laimi Erckie ◽  
Opeyemi Adedoja ◽  
Sjirk Geerts ◽  
Ernita van Wyk ◽  
J. Stephen Boatwright

Sign in / Sign up

Export Citation Format

Share Document