Factors that influence above-ground biomass in tropical forests in the Amazon?5 answersFactors influencing above-ground biomass (AGB) in tropical forests in the Amazon include the interaction between the signal and canopy structure, human intervention through selective logging, vegetation indices like NDVI, and the time and intensity of logging activities. The studies highlight the importance of variables such as Pv, σ°HH, αS2, τm, ΦS3, and ΦS2 in estimating AGB. Artificial neural networks, LiDAR data, and Landsat-8 variables are utilized to accurately predict AGB, emphasizing the role of machine learning algorithms like RF and SVM. Additionally, the recovery of AGB post-logging is influenced by monitoring time and logging intensity, with forests able to regain initial AGB levels in areas of low exploitation intensity within 12 years.
What factors influence the distribution of terrestrial biomass?5 answersThe distribution of terrestrial biomass is influenced by various factors highlighted in the research papers. Warming has been shown to increase root: shoot ratio, with a greater effect in drier habitats and for plants associated with arbuscular mycorrhizal fungi. Changes in terrestrial biomass due to warming vary among plant functional types, with woody species experiencing a greater increase compared to herbaceous species. Forest biomass dynamics are affected by environmental factors, disturbances, and ecological processes, with biomass density consistently increasing globally since 1990, potentially due to elevated CO2 levels. Accurate estimation of above-ground biomass distribution across different scales requires consideration of wood specific gravity variations, which significantly impact biomass estimates and necessitate further research for improved large-scale mapping.
Better tree biomass estimation formula for tropical agroforestry ?5 answersMachine learning algorithms, such as RandomForest, Support Vector Machine (SVM), K-nearest neighbor (KNN), and Artificial Neural Network (ANN), have shown promise in estimating aboveground biomass in tropical forests. These algorithms outperform traditional methods like multilinear regression, providing more accurate results. Among the machine learning algorithms, RandomForest has been found to be the best choice for predicting aboveground biomass, reducing over- or under-estimation problems. Additionally, the use of vegetation indices as predictor variables has yielded accurate results and demonstrated strong modeling power. Allometric models based on tree attributes obtained from terrestrial laser scanning (TLS) point clouds, such as crown diameter, have also shown to provide accurate aboveground biomass estimates, especially for large trees. Therefore, a combination of machine learning algorithms and TLS-derived allometric models could be a better approach for estimating tree biomass in tropical agroforestry systems.
Does elevation exert an influence on the distribution of trees?5 answersElevation exerts a significant influence on the distribution of trees. Environmental conditions become harsher at higher elevations, affecting the genetic structure of plants. Temperature decline with increasing elevation shapes plant community biodiversity and ecosystem dynamics. Changes in biodiversity with elevation are consistent with competing hypotheses related to water-energy dynamics, species-energy relationship, tropical niche conservatism, and out of the tropics hypothesis. Conspecific density dependence varies with elevation, impacting tree survival and growth. Phenotypic responses of trees to light and allocation of carbon to roots are influenced by elevation. These findings highlight the importance of elevation in shaping the distribution, genetic structure, and functional properties of tree species, with implications for conservation and management strategies.
What are the factors that influence the distribution of aboveground biomass in forests?5 answersThe distribution of aboveground biomass in forests is influenced by multiple factors. Stand structural characteristics, such as tree density, diameter at breast height, and basal area, play a significant role in determining aboveground biomass levels. Climate factors, including mean annual temperature and mean annual precipitation, also have an impact on aboveground biomass distribution. Additionally, soil factors, such as pH, can affect the proportion of belowground biomass in forests. Biotic factors, such as average height of the stand, and abiotic factors, such as annual precipitation, contribute to the spatial heterogeneity of aboveground forest biomass. Furthermore, regional and local biotic processes, including species diversity and stand structural heterogeneity, along with environmental factors, such as soil fertility and climatic water availability, jointly regulate aboveground biomass in tropical forests. Overall, these findings highlight the complex interactions between various factors that influence the distribution of aboveground biomass in forests.
What factors affect the amount of below-ground biomass in trees?3 answersFactors that affect the amount of below-ground biomass in trees include climate factors such as temperature and precipitation. Soil factors, such as pH, also have a strong influence on below-ground biomass. Additionally, the presence of multiple tree species in a forest can affect below-ground biomass responses to global change, as shown in a study on Alnus glutinosa, Betula pendula, and Fagus sylvatica. Furthermore, nutrient availability, specifically nitrogen (N) and phosphorus (P), can impact below-ground biomass, with increased N and P leading to decreased below-ground biomass in some cases. Light availability also plays a role, as sites with low canopy light penetration showed a decrease in below-ground biomass with N addition. Overall, climate factors, soil factors, tree species composition, and nutrient availability are important factors influencing below-ground biomass in trees.