Relationships between tree stand density and burn severity as measured by the Composite Burn Index following a ponderosa pine forest wildfire in the American Southwest

The Trigo fire burned 5548 ha of the Manzano Mountains in central New Mexico in 2008. The fire burned with mixed severity through ponderosa pine (Pinus ponderosa) stands on the Cibola National Forest and private lands. The burned area exhibited a range of stand densities enabling this research to quantify the relationship between variation in tree density and burn severity using the Composite Burn Index (CBI) severity classification. Across 90 CBI plots, high tree density was strongly associated with high burn severity. The CBI method allowed classification of burn severity to a range of forest vertical fuels strata. Tree mortality and duff consumption are two attributes that recorded higher severity in plots with higher tree densities. The CBI approach is designed for rapid on-the-ground assessments; to compliment this procedure a rapid visual classification of stand density was tested to determine its accuracy for land managers. This visual assessment correlated well with quantitative measurements of tree density. Since density classes were also highly correlated with CBI scores they may therefore be a good predictor of burn severity in a stand. This is a more rapid way for land managers to categorize stand density than traditional density measurements. These findings demonstrate that reducing tree density in southwestern ponderosa pine stands may significantly lower burn severity resulting from wildfire

Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity

Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity

The status of the world's land and marine mammals: diversity, threat, and knowledge

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action

The regulation of design in global architecture firms : embedding and emplacing buildings.

The emergence of global architecture firms and their role in the production of city architectures raises a number of questions for social scientists. For example, how— indeed do—global architects ensure that the buildings they design are ‘in place’ and appropriate for the urban cultural, economic, social and political contexts in which they are to be built? The aim of the paper is to consider this question. ‘Regulation’ is taken in its broadest sense and the paper explores the role of standards and codes as well as other forms of social regulation in the process of emplacing designs. It is argued that, in order to understand how buildings are put in their place, analysis is needed of both the design-side adaptations architects make to buildings and also the consumption side regulation of designs and the way the behaviours of those inhabiting buildings produce ‘local’ meaning