Examining effective use of data sources and modeling algorithms for improving biomass estimation in a moist tropical forest of the Brazilian Amazon

Previous research has explored the potential to integrate lidar and optical data in aboveground biomass(AGB)estimation,but how different data sources,vegetation types,and modeling algorithms influence AGB estimation is poorly understood.This research conducts a comparative analysis of different data sources and modeling approaches in improving AGB estimation.RapidEye-based spectral responses and textures,lidar-derived metrics,and their combination were used to develop AGB estimation models.The results indicated that(1)overall,RapidEye data are not suitable for AGB estimation,but when AGB falls within 50–150 Mg/ha,support vector regression based on stratification of vegetation types provided good AGB estimation;(2)Lidar data provided stable and better estimations than RapidEye data;and stratification of vegetation types cannot improve estimation;(3)The combination of lidar and RapidEye data cannot provide better performance than lidar data alone;(4)AGB ranges affect the selection of the best AGB models,and a combination of different estimation results from the best model for each AGB range can improve AGB estimation;(5)This research implies that an optimal procedure for AGB estimation for a specific study exists,depending on the careful selection of data sources,modeling algorithms,forest types,and AGB ranges.

Microorganisms in Small Patterned Ground Features and Adjacent Vegetated Soils along Topographic and Climatic Gradients in the High Arctic, Canada

In this study, we determine differences in total biomass of soil microorganisms and community structure (using the most probable number of bacteria (MPN) and the number of fungal genera) in patterned ground features (PGF) and adjacent vegetated soils (AVS) in mesic sites from three High Arctic islands in order to characterize microbial dynamics as affected by cryoturbation, and a broad bioclimatic gradient. We also characterize total biomass of soil microorganisms and the most probable number of bacteria along a topographic gradient within each bioclimatic subzone to evaluate whether differences in topography lead to differences in microbial dynamics at a smaller scale. We found total microbial biomass C, the most probable number of heterotrophic bacteria, and fungal genera vary along this bioclimatic gradient. Microbial biomass C decreased with increasing latitude. Overall, microbial biomass C, MPN and the number of fungal isolates were higher in AVS than in PGFs. The effects which topographic position had on microbial biomass C varied across the bioclimatic gradient as there was no effect of topographic position in Isachsen (subzone A) and Mould Bay (subzone B), when compared to Green Cabin (subzone C, warmer site).There was no effect of topographic position on MPN counts at Mould Bay and Green Cabin. However, in Isachsen, MPN counts were highest in the wet topographic position as compared to the mesic and dry. In conclusion, PGFs seem to decouple the effect climate that might have on the total biomass of soil microorganisms along the bioclimatic gradient;and influence gets ameliorated as latitude increases. Similarly, the effect of topography on the total microbial biomass is significant at the warmest bioclimatic zone of the gradient. Thus, climate and topographic effects on total microbial biomass increase with warmer climate.

Soil Nutrients, Landscape Age, and <i>Sphagno-Eriophoretum vaginati</i>Plant Communities in Arctic Moist-Acidic Tundra Landscapes

Most research exploring the relationship between soil chemistry and vegetation in Alaskan Arctic tundra landscapes has focused on describing differences in soil elemental concentrations (e.g. C, N and P) of areas with contrasting vegetation types or landscape age. In this work we assess the effect of landscape age on physico-chemical parameters in organic and mineral soils from two long-term research sites in northern Alaska, the Toolik Lake and Imnavait grids. These two sites have contrasting landscape age but similar vegetation composition. We also used correlation analysis to evaluate if differences in any of these parameters were linked with between-site variation in the abundance of growth forms. Our analysis was narrowed to soils in Sphagno-Eriophoretum vaginati plant communities. We found no significant differences between these sites for most parameters evaluated, except for total Ca which was significantly higher in organic soils from Imnavait vs. Toolik and total Na which was significantly higher in mineral horizons from Toolik compared to Imnavait. Moreover, the abundance of non-Sphagnum mosses was positively correlated with total Ca in organic soils, whereas the abundance of forbs, non-Sphagnum mosses and bryophytes was negatively correlated with total Na in mineral soils. We suggest that differences in the concentration of these two elements are most likely tied to landscape age differences between these sites. However, since observed dissimilarity in terms of total Ca in organic soils and total Na in mineral soils is concordant with correlation patterns observed between these elements and the aforementioned growth forms, it is likely that existing differences in vegetation composition between these sites are also influencing the concentration of these elements in soils, particularly that of Ca, since non-Sphagnum mosses are dominant above organic soils and are therefore expected to significantly influence biogeochemical processes at this horizon. Thus, we conclude that except for organic Ca and mineral Na, there is little difference between these sites in terms of their soil physico-chemical properties. We suggest that most of the influence of landscape age on evaluated parameters is masked by factors such as moderate cryoturbation and similarities in terms of vegetation properties and climate. These observations are relevant as they suggest a linkage between soil chemistry and vegetation composition in this tundra region.

Functional attributes of two subtropical shrubs and implications for the distribution and management of endangered bird habitat

Aims The fruits of Erithalis fruticosa l.and Lantana involucrata l.are important in the diet of u federally endangered Kirtland’s Warblers(Setophaga kirtlandii)wintering in the bahamas archi-pelago.These two shrubs occur in tropical and subtropical dry forests,including forests that have been subjected to recent dis-turbance.Despite their importance to the endangered warbler,the disturbance ecology of these shrubs is poorly understood.We sought to determine,based on functional characteristics of the plants,whether their presence is favored by a particular type or regime of disturbance.Methods We used data from field experiments(seed broadcasting and shrub cutting)conducted on the island of Eleuthera,The bahamas to determine mechanisms of and conditions favoring establishment and persistence(‘vital attributes’)of E.fruticosa and L.involucrata,which enabled categorization according to the plant functional types defined by Noble and slatyer(1980).We then compared hypothesized distributions of these plant functional types among different anthropogenic disturbance regimes to observed distribu-tions of E.fruticosa and L.involucrata in order to identify distur-bance regimes most likely to produce habitat used by Kirtland’s Warblers.Important Findings E.fruticosa and L.involucrata were functionally categorized as widely dispersed but largely shade intolerant species capable of establishing or regenerating individuals after disturbance via both seeds and vegetative mechanisms.both hypothesized and observed distribution patterns indicated the shrubs were favored by a regime of frequent disturbance producing open canopy and ground layers.among the anthropogenic disturbances we examined,areas of large-scale land clearing combined with subsequent goat graz-ing most often supported E.fruticosa and L.involucrata,while the shrubs were relatively rare in burned areas.utilizing the plant functional type framework in combination with field data to evaluate predictions of species occurrence among different disturbances regimes provides a strong theoretical basis for conservation strategies.understanding which disturbance types favor a habitat of concern and the mechanisms by which they do so can aid the prior-itization of areas for protection or the design of habitat management protocols.

Forest Tenure and Sustainable Forest Management

We reviewed the principles and key literature related to forest tenure and sustainable forest management, and then examined the status of sustainable forestry and land ownership at the aggregate national level for major forested countries. The institutional design principles suggested by Ostrom are well accepted for applications to public, communal, and private lands. The analyses of countries as a whole suggest that problems of forest land loss and sustainable forest management are related to the amount of public lands owned, as well as the difference between developed and developing countries. Developed countries have largely achieved a stable level of land use and resource extraction after centuries of exploitation of forests and natural resources. Many developed countries do have greater amounts of private forest land than developing countries, which have occurred as the countries transfer lands to private owners in the course of development. Public lands and management approaches require diligence, but can be developed to meet the design criteria suggested by tenure rights theorists. Private or communal ownership is often considered superior, but also must meet the criteria suggested above in order to foster sustainable forest management in poor countries.

Landform type mediates compositional change in a hurricane-disturbed subtropical forest

Background:Categorization of topographical features into landform type is a long-standing method for understanding physiographic patterns in the environment.Differences in forest composition between landform types are driven primarily by concurrent differences in soil composition and moisture,but also disturbance regime.Many studies have focused on the interaction between fire disturbance,succession,and landforms,but the effects of hurricane disturbance on compositional differences between landforms are poorly understood.In the study presented here,we assess compositional and structural differences between landform types in the tree community of a young sub-tropical forest that is frequently subjected to hurricanes.Specifically,we ask whether the tree community(1)changed structurally over the study period,(2)experienced compositional change over the study period,(3)is compositionally different between landform types,and(4)exhibits compositional change mediated by landform type.Results:The tree community experienced significant structural change over the course of our study,but compositional change was only significant for some landforms.Conclusion:Despite large-scale,intense,and frequent hurricane disturbance to our study system,compositional change in the tree community was localized and only significant for some landform types.

Linking science and decision making to promote an ecology for the city:practices and opportunities

To promote urban sustainability and resilience,there is an increasing demand for actionable science that links science and decision making based on social-ecological knowledge.Approaches,frameworks,and practices for such actionable science are needed and have only begun to emerge.We propose that approaches based on the co-design and co-production of knowledge can play an essential role to meet this demand.Although the antecedents for approaches to the co-design and co-production of knowledge are decades old,the integration of science and practice to advance urban sustainability and resilience that we present is different in several ways.These differences include the disciplines needed,diversity and number of actors involved,and the technological infrastructures that facilitate local-to global connections.In this article,we discuss how the new requirements and possibilities for co-design,co-production,and practical use of social-ecological research can be used as an ecology for the city to promote urban sustainability and resilience.While new technologies are part of the solution,traditional approaches also remain important.Using our urban experiences with long-term,place-based research from several U.S.Long-Term Ecological Research sites and U.S.Department of Agriculture,Forest Service Urban Field Stations,we describe a dynamic framework for linking research with decisions.We posit that this framework,coupled with a user-defined,theory-based approach to science,is instrumental to advance both practice and science.Ultimately,cities are ideal places for integrating basic science and decision making,facilitating flows of information through networks,and developing sustainable and resilient solutions and futures.