scholarly journals Associations of bird and bat species richness with temperature and remote sensing‐based vegetation structure on a tropical mountain

Biotropica ◽  
2021 ◽  
Author(s):  
Anna‐Valeska Bettina Vogeler ◽  
Insa Otte ◽  
Stefan Ferger ◽  
Maria Helbig‐Bonitz ◽  
Andreas Hemp ◽  
...  
2021 ◽  
Vol 13 (3) ◽  
pp. 507
Author(s):  
Tasiyiwa Priscilla Muumbe ◽  
Jussi Baade ◽  
Jenia Singh ◽  
Christiane Schmullius ◽  
Christian Thau

Savannas are heterogeneous ecosystems, composed of varied spatial combinations and proportions of woody and herbaceous vegetation. Most field-based inventory and remote sensing methods fail to account for the lower stratum vegetation (i.e., shrubs and grasses), and are thus underrepresenting the carbon storage potential of savanna ecosystems. For detailed analyses at the local scale, Terrestrial Laser Scanning (TLS) has proven to be a promising remote sensing technology over the past decade. Accordingly, several review articles already exist on the use of TLS for characterizing 3D vegetation structure. However, a gap exists on the spatial concentrations of TLS studies according to biome for accurate vegetation structure estimation. A comprehensive review was conducted through a meta-analysis of 113 relevant research articles using 18 attributes. The review covered a range of aspects, including the global distribution of TLS studies, parameters retrieved from TLS point clouds and retrieval methods. The review also examined the relationship between the TLS retrieval method and the overall accuracy in parameter extraction. To date, TLS has mainly been used to characterize vegetation in temperate, boreal/taiga and tropical forests, with only little emphasis on savannas. TLS studies in the savanna focused on the extraction of very few vegetation parameters (e.g., DBH and height) and did not consider the shrub contribution to the overall Above Ground Biomass (AGB). Future work should therefore focus on developing new and adjusting existing algorithms for vegetation parameter extraction in the savanna biome, improving predictive AGB models through 3D reconstructions of savanna trees and shrubs as well as quantifying AGB change through the application of multi-temporal TLS. The integration of data from various sources and platforms e.g., TLS with airborne LiDAR is recommended for improved vegetation parameter extraction (including AGB) at larger spatial scales. The review highlights the huge potential of TLS for accurate savanna vegetation extraction by discussing TLS opportunities, challenges and potential future research in the savanna biome.


2021 ◽  
Vol 13 (2) ◽  
pp. 257 ◽  
Author(s):  
Shaun R. Levick ◽  
Tim Whiteside ◽  
David A. Loewensteiner ◽  
Mitchel Rudge ◽  
Renee Bartolo

Savanna ecosystems are challenging to map and monitor as their vegetation is highly dynamic in space and time. Understanding the structural diversity and biomass distribution of savanna vegetation requires high-resolution measurements over large areas and at regular time intervals. These requirements cannot currently be met through field-based inventories nor spaceborne satellite remote sensing alone. UAV-based remote sensing offers potential as an intermediate scaling tool, providing acquisition flexibility and cost-effectiveness. Yet despite the increased availability of lightweight LiDAR payloads, the suitability of UAV-based LiDAR for mapping and monitoring savanna 3D vegetation structure is not well established. We mapped a 1 ha savanna plot with terrestrial-, mobile- and UAV-based laser scanning (TLS, MLS, and ULS), in conjunction with a traditional field-based inventory (n = 572 stems > 0.03 m). We treated the TLS dataset as the gold standard against which we evaluated the degree of complementarity and divergence of structural metrics from MLS and ULS. Sensitivity analysis showed that MLS and ULS canopy height models (CHMs) did not differ significantly from TLS-derived models at spatial resolutions greater than 2 m and 4 m respectively. Statistical comparison of the resulting point clouds showed minor over- and under-estimation of woody canopy cover by MLS and ULS, respectively. Individual stem locations and DBH measurements from the field inventory were well replicated by the TLS survey (R2 = 0.89, RMSE = 0.024 m), which estimated above-ground woody biomass to be 7% greater than field-inventory estimates (44.21 Mg ha−1 vs 41.08 Mg ha−1). Stem DBH could not be reliably estimated directly from the MLS or ULS, nor indirectly through allometric scaling with crown attributes (R2 = 0.36, RMSE = 0.075 m). MLS and ULS show strong potential for providing rapid and larger area capture of savanna vegetation structure at resolutions suitable for many ecological investigations; however, our results underscore the necessity of nesting TLS sampling within these surveys to quantify uncertainty. Complementing large area MLS and ULS surveys with TLS sampling will expand our options for the calibration and validation of multiple spaceborne LiDAR, SAR, and optical missions.


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.


2017 ◽  
Vol 118 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Mauricio Neves Godoi ◽  
Rudi Ricardo Laps ◽  
Danilo Bandini Ribeiro ◽  
Camila Aoki ◽  
Franco Leandro de Souza

2015 ◽  
Vol 4 (3) ◽  
pp. 166-176
Author(s):  
Hom N Pathak

 The succession in areas once vegetated before the disturbance to a forest as climax community is called secondary succession. Secondary succession is influenced by soil type and the vegetation that invades the community. During the literature survey we found that the cropping areas are abandoned in different parts of the world and the fallows left are under secondary succession. There the socio-economy of the people has been found to affect the succession. Species diversity, species richness, rate of replacement and the soil type etc. have been studied by succession researchers. Succession study has also been carried out by using the tools like remote sensing, geographical information system etc.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 166-176


2012 ◽  
Vol 40 (3) ◽  
pp. 211-221 ◽  
Author(s):  
BRADLEY B. WALTERS ◽  
LISA HANSEN

SUMMARYIslands of the West Indies are among the most historically impacted by agriculture, yet agricultural influences on forests there have been little studied. This research compared tree species richness and vegetation structure between farmed lands, post-agriculture secondary forests and mature remnant forests in two watersheds in Saint Lucia, and sought to understand the current distribution of these habitats in terms of land use and watershed topography. Farms devoted to annual crops had few trees and much exposed soil. By contrast, agroforests had abundant (mostly planted) trees and vegetation structure comparable to secondary forests. Secondary forests had highest overall species richness, but mature forests had the most developed vegetation structure. Variations in habitat distribution reflected different land use histories, with the more rugged west coast long dominated by tree crop farming and the east coast experiencing a recent boom-bust cycle in bananas. Mature and secondary forests were more likely found at higher altitude, further from roads and at sites more difficult to access, the combined result of government protection of key forest and watershed reserves and farmers’ preferential abandonment of marginal lands. For conservationists, this return of forests is reason for optimism and it presents strategic opportunities for public land acquisition or collaborative management to further forest and watershed protection objectives.


2018 ◽  
Vol 206 ◽  
pp. 240-253 ◽  
Author(s):  
Hamed Gholizadeh ◽  
John A. Gamon ◽  
Arthur I. Zygielbaum ◽  
Ran Wang ◽  
Anna K. Schweiger ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document