Fuel types misrepresent forest structure and composition in interior British Columbia: a way forward.

Background: A clear understanding of the connectivity, structure, and composition of wildland fuels is essential for effective wildfire management. However, fuel typing and mapping are challenging owing to a broad diversity of fuel conditions and their spatial and temporal heterogeneity. In Canada, fuel types and potential fire behavior are characterized using the Fire Behavior Prediction (FBP) System, which uses an association approach to categorize vegetation into 16 fuel types based on stand structure and composition. In British Columbia (BC), provincial and national FBP System fuel type maps are derived from remotely sensed forest inventory data and are widely used for wildfire operations, fuel management, and scientific research. Despite their widespread usage, the accuracy and applicability of these fuel type maps have not been formally assessed. To address this knowledge gap, we quantified the agreement between on-site assessments and provincial and national fuel type maps in interior BC. Results: We consistently found poor correspondence between field assessment data and both provincial and national fuel types. Mismatches were particularly frequent for (i) dry interior ecosystems, (ii) mixedwood and deciduous fuel types, and (iii) post-harvesting conditions. For 58% of field plots, there was no suitable match to the extant fuel structure and composition. Mismatches were driven by the accuracy and availability of forest inventory data and low applicability of the Canadian FBP System to interior BC fuels. Conclusions: The fuel typing mismatches we identified can limit scientific research, but also challenge wildfire operations and fuel management decisions. Improving fuel typing accuracy will require a significant effort in fuel inventory data and system upgrades to adequately represent the diversity of extant fuels. To more effectively link conditions to expected fire behavior outcomes, we recommend a fuel classification approach and emphasis on observed fuels and measured fire behavior data for the systems we seek to represent. Supplementary Information: The online version contains supplementary material available at 10.1186/s42408-024-00249-z.

Antecedentes: Un entendimiento claro sobre la conectividad, estructura, y composición de los combustibles vegetales es esencial para un manejo efectivo de los incendios de vegetación. Sin embargo, la tipificación y mapeo de los combustibles son aspectos desafiantes debido a la amplia diversidad de las condiciones de los combustibles y su variabilidad espacial y temporal. En Canadá, los tipos de combustibles y el comportamiento potencial del fuego están caracterizados por el uso del Sistema de Predicción del Comportamiento del Fuego (Fire Behavior Prediction System, FBP), el cual usa una "aproximación asociada" para categorizar la vegetación en 16 tipos de combustibles basados en la estructura y composición de los rodales. En la Columbia Británica (BC) los mapas del sistema provincial y nacional de FBP son derivados de datos de inventarios tomados mediante sensores remotos, que son ampliamente usados para operaciones de incendios de vegetación, manejo de combustibles, e investigación científica. A pesar de su amplio uso, la exactitud y aplicabilidad de esos mapas de tipos de combustibles no han sido adecuadamente comprobadas. Para determinar este vacío en el conocimiento, cuantificamos la concordancia entre las determinaciones in situ y los mapas de combustibles provinciales y nacionales en el interior de BC. Resultados: Encontramos consistentemente una pobre correspondencia entre las determinaciones de los datos de campo y los tipos de combustibles provinciales y nacionales. Los desfasajes fueron particularmente frecuentes para: i) los ecosistemas secos del interior, ii) bosques mixtos y tipos de combustibles en bosques deciduos, y iii) condiciones de postcosecha. Para el 58% de las parcelas a campo, no hubo una concordancia adecuada entre la estructura y composición existentes. Estos desajustes fueron derivados de la exactitud y disponibilidad de datos del inventario forestal, y la baja aplicabilidad del Sistema FBP a los combustibles del interior de la Columba Británica. Conclusiones: Los desajustes en la determinación de los tipos de combustibles que nosotros identificamos pueden limitar la investigación científica, pero también es un desafío para las decisiones en las operaciones de incendios y en el manejo de los combustibles. El mejoramiento de la exactitud en la determinación de tipos de combustibles requerirá de un esfuerzo significativo en el inventario de datos y sistemas mejorados para representar adecuadamente la diversidad de los combustibles existentes. Para ligar más efectivamente las condiciones a los resultados del comportamiento, recomendamos una aproximación a la clasificación de los combustibles y énfasis en datos de los combustibles observados y del comportamiento medido para los sistemas que pretendemos representar.

Modeling instream temperature from solar insolation under varying timber harvesting intensities using RPAS laser scanning.

Stream temperatures are influenced by the amount of solar insolation they receive. Increasing stream temperatures associated with climate warming pose detrimental health risks to freshwater ecosystems. In British Columbia (BC), Canada, timber harvesting along forested streams is managed using riparian buffer zones of varying widths and designations. Within buffer zones, depending on distance from the stream, selective thinning may be permitted or harvest may be forbidden. In this study, we used airborne laser scanning (ALS) point cloud data acquired via a remotely piloted aircraft system (RPAS) to derive forest canopy characteristics that were then used to estimate daily incoming summer and fall solar insolation for five stream reaches in coastal conifer-dominated temperate forests in Vancouver Island, BC, Canada. We then examined empirical relationships between estimated insolation and actual instream temperature measurements. Based on these empirical relationships, the potential effects of timber harvest on instream temperatures were simulated by comparing scenarios of different riparian forest harvest intensities. Our results indicated that modeled solar insolation explained 43-90 % of the variation in observed stream reach temperatures, and furthermore, when a single cold-water stream reach was excluded explained an overall 81 % of variation. Simulated harvesting scenarios generally projected increases in maximum stream reach temperatures 1-2 °C in summer and early fall months. However, in a full clearcut scenario (i.e. where all trees were removed), maximum stream reach temperatures increased as much as 5.8 °C. Our results emphasize the importance of retaining riparian vegetation for the maintenance of habitable temperatures for freshwater-reliant fish with thermal restrictions. In addition, we demonstrate the feasibility of RPAS-based monitoring of stream reach shading and canopy cover, enabling detailed assessment of environmental stressors faced by fish populations under climate warming.

Effectiveness of landscape indicators for explaining the variability of benthic macro-invertebrates in urban streams.

Landscape indicators - measures of land use and land cover - are widely used as proxies for monitoring urban stream conditions, particularly for benthic invertebrates which are often negatively impacted by watershed urbanization. However, multi-scale and nonlinear relationships between benthic macroinvertebrates and landscape configuration derived from fine spatial resolution land cover are not well explored. Here, we developed a series of landscape indicators and assessed their effectiveness in explaining the variability of benthic macroinvertebrate communities in 63 streams across the Greater Vancouver Region in British Columbia, Canada. We asked: 1) How effective are multi-scale landscape indicators in explaining the variability of instream benthic macroinvertebrates? 2) Does the explanatory power of landscape indicators vary at different spatial scales? 3) Do different urban forest classification schemes and their spatial configurations impact the explanatory power of landscape indicators? We developed high spatial resolution (5-m) landscape indicators and evaluated their utility in statistical models explaining taxa richness, instream benthic indices of biological integrity (B-IBI), % Ephemeroptera, Plecoptera, and Trichoptera (EPT), and % Oligochaetes. For all benthic responses, landscape indicators measured at the watershed scale explained 5-25% more variation than riparian-based indicators. Combining indicators mapped at multiple scales further improved the explanatory power of landscape indicators for % EPT and % Oligochaetes, ultimately explaining over 70% of the variability of benthic macro-invertebrates in streams. Distinguishing deciduous and coniferous forest types improved the explanatory power of landscape indicators in a riparian model for B-IBI by 10%. When considering the spatial arrangement of land cover, patch density of forests in the surrounding watersheds of stream explained as much as 47% of the variability in % Oligochaetes. Our results highlight the importance of investigating nonlinear relationships between benthic macroinvertebrates and landscape configuration. This monitoring approach is transferable across cities interested in maintaining the ecological health of urban streams while supporting urban expansion and growth.

Assessing the Cumulative Social Effects of Projects: Lessons from Canadian Hydroelectric Development.

Cumulative effects assessments are often expected to include an analysis of cumulative social effects to people, their communities, and livelihoods caused by resource development projects and land use activities. Understanding cumulative social effects is important for decisions about prospective resource development projects, but there has been limited attention devoted to how to complete such an assessment. This paper critically examines how cumulative effects frameworks are applied to social impacts during environmental assessments. We do this by analyzing semi-structured interviews exploring practitioner experience in environmental assessments for hydroelectric development in British Columbia and Manitoba, Canada. The results provide a conceptual framework for cumulative social effects and illustrate how identified challenges for cumulative effects assessment are exacerbated by social impacts that introduce additional complexities in impact identification, assessment, and decision-making. The paper concludes with a discussion of how these challenges can be addressed and recommendations for improving environmental assessment practice.

The influence of early-life residential exposure to different vegetation types and paved surfaces on early childhood development: A population-based birth cohort study.

BACKGROUND: Growing evidence suggests that exposure to green space is associated with improved childhood health and development, but the influence of different green space types remains relatively unexplored. In the present study, we investigated the association between early-life residential exposure to vegetation and early childhood development and evaluated whether associations differed according to land cover types, including paved land. METHODS: Early childhood development was assessed via kindergarten teacher-ratings on the Early Development Instrument (EDI) in a large population-based birth cohort (n = 27,539) in Metro Vancouver, Canada. The residential surrounding environment was characterized using a high spatial resolution land cover map that was linked to children by six-digit residential postal codes. Early-life residential exposure (from birth to time of EDI assessment, mean age = 5.6 years) was calculated as the mean of annual percentage values of different land cover classes (i.e., total vegetation, tree cover, grass cover, paved surfaces) within a 250 m buffer zone of postal code centroids. Multilevel models were used to analyze associations between respective land cover classes and early childhood development. RESULTS: In adjusted models, one interquartile range increase in total vegetation percentage was associated with a 0.33 increase in total EDI score (95% CI: 0.21, 0.45). Similar positive associations were observed for tree cover (ß-coefficient: 0.26, 95% CI: 0.15, 0.37) and grass cover (ß-coefficient: 0.12, 95% CI: 0.02, 0.22), while negative associations were observed for paved surfaces (ß-coefficient: -0.35, 95% CI: -0.47, -0.23). CONCLUSIONS: Our findings indicate that increased early-life residential exposure to vegetation is positively associated with early childhood developmental outcomes, and that associations may be stronger for residential exposure to tree cover relative to grass cover. Our results further indicate that childhood development may be negatively associated with residential exposure to paved surfaces. These findings can inform urban planning to support early childhood developmental health.

Assessing the association between lifetime exposure to greenspace and early childhood development and the mediation effects of air pollution and noise in Canada: a population-based birth cohort study.

BACKGROUND: Exposure to greenspace is associated with improved childhood development, but the pathways behind this relationship are insufficiently understood. Therefore, we aimed to investigate the association between lifetime residential exposure to greenspace and early childhood development and evaluate the extent to which this association is mediated by reductions in traffic-related air pollution and noise. METHODS: This population-based birth cohort study comprised singleton births in Metro Vancouver, BC, Canada, between April 1, 2000, and Dec 31, 2005. Children and mothers had to be registered with the mandatory provincial health insurance programme, Medical Services Plan, and have lived within the study area from the child's birth to the time of outcome assessment. Early childhood development was assessed via teacher ratings on the Early Development Instrument (EDI), and we used the total EDI score as the primary outcome variable. We estimated greenspace using percentage vegetation derived from spectral unmixing of annual Landsat satellite image composites. Lifetime residential exposure to greenspace was estimated as the mean of annual percentage vegetation values within 250 m of participants' residential postal codes. Multilevel modelling, adjusted for eight covariates, was used to investigate associations between greenspace exposure and EDI scores. We estimated the mediation effects of nitrogen dioxide (NO2), fine particulate matter (PM2·5), and noise levels using causal mediation analyses. FINDINGS: Of the 37 745 children born in Metro Vancouver between April 1, 2000, and Dec 31, 2005, 27 372 were included in our final study sample. In the adjusted model, 1 IQR increase in percentage vegetation was associated with a 0·16 (95% CI 0·04-0·28; p=0·0073) increase in total EDI score, indicating small improvements in early childhood development. We estimated that 97·1% (95% CI 43·0-396·0), 29·5% (12·0-117·0), and 35·2% (17·9-139·0) of the association was mediated through reductions in NO2, PM2·5, and noise, respectively. INTERPRETATION: Increased exposure to residential greenspace might improve childhood development by reducing the adverse developmental effects of traffic-related exposures, especially NO2 air pollution. Our study supports the implementation of healthy urban planning and green infrastructure interventions. FUNDING: Canadian Institutes of Health Research.

Conceptual Links between Landscape Diversity and Diet Diversity: A Roadmap for Transdisciplinary Research.

Malnutrition linked to poor quality diets affects at least 2 billion people. Forests, as well as agricultural systems linked to trees, are key sources of dietary diversity in rural settings. In the present article, we develop conceptual links between diet diversity and forested landscape mosaics within the rural tropics. First, we summarize the state of knowledge regarding diets obtained from forests, trees, and agroforests. We then hypothesize how disturbed secondary forests, edge habitats, forest access, and landscape diversity can function in bolstering dietary diversity. Taken together, these ideas help us build a framework illuminating four pathways (direct, agroecological, energy, and market pathways) connecting forested landscapes to diet diversity. Finally, we offer recommendations to fill remaining knowledge gaps related to diet and forest cover monitoring. We argue that better evaluation of the role of land cover complexity will help avoid overly simplistic views of food security and, instead, uncover nutritional synergies with forest conservation and restoration.

Different types of urban natural environments influence various dimensions of self-reported health.

BACKGROUND: Growing evidence suggests health benefits of natural environments. Yet, the effects of different types of natural environments (vegetation and water features) and forms of human-nature contact (access versus exposure) remain relatively unexplored. METHODS: A cross-sectional observational survey was used to analyse the relationship between both access and exposure to different types of urban natural environments and health outcomes in Metro Vancouver, Canada. Data for health outcomes (self-reported general health, mental health, and common mental disorders) and key confounders were obtained from the 2013-2014 Canadian Community Health Survey. Natural environments were quantified using local land use and land cover data, and linked to survey respondents by six-digit postal code. Access was defined as living within 300 m of a public greenspace (≥ 1 hectare) and exposure as the percentage of different land cover types within multiple buffer distances of postal code centroids. Separate logistic regression models were used to estimate the associations of the access and exposure metrics with the three health outcomes. RESULTS: Exposure to water within 1,000 m buffers was associated with a reduced odds of reporting poor general health (OR = 0.982, 95% CI = 0.965, 0.999). A similar association was found for exposure to shrub and grass-herb vegetation types for reported mental health and common mental disorder, respectively (OR = 0.741, 95% CI = 0.576, 0.953 for shrubs in 250 m; OR = 0.737, 95% CI = 0.577, 0.942 for shrubs in 500 m; OR = 0.731, 95% CI = 0.570, 0.938 for shrubs in 1,000 m; OR = 0.980, 95% CI = 0.965, 0.995 for grass-herbs in 250 m). Neither access to public greenspace nor aggregated greenspace exposure were associated with self-reported health. Results from stratified analyses suggest that observed associations between human-nature contact and self-reported health differ according to gender. CONCLUSIONS: Results suggest that type of natural environment should be considered in future research studying the health-promoting aspects of natural environments, and that positive health effects may be more consistent for daily life exposure than for access to public greenspace.

Shifting gears: Diversification, intensification, and effort increases in small-scale fisheries (1950-2010).

Locally sustainable resource extraction activities, at times, transform into ecologically detrimental enterprises. Understanding such transitions is a primary challenge for conservation and management of many ecosystems. In marine systems, over-exploitation of small-scale fisheries creates problems such as reduced biodiversity and lower catches. However, long-term documentation of how governance and associated changes in fishing gears may have contributed to such declines is often lacking. Using fisher interviews, we characterized fishing gear dynamics over 60 years (1950-2010) in a coral reef ecosystem in the Philippines subject to changing fishing regulations. In aggregate fishers greatly diversified their use of fishing gears. However, most individual fishers used one or two gears at a time (mean number of fishing gears < 2 in all years). Individual fishing effort (days per year) was fairly steady over the study period, but cumulative fishing effort by all fishers increased 240%. In particular, we document large increases in total effort by fishers using nets and diving. Other fishing gears experienced less pronounced changes in total effort over time. Fishing intensified through escalating use of non-selective, active, and destructive fishing gears. We also found that policies promoting higher production over sustainability influenced the use of fishing gears, with changes in gear use persisting decades after those same policies were stopped. Our quantitative evidence shows dynamic changes in fishing gear use over time and indicates that gears used in contemporary small-scale fisheries impact oceans more than those used in earlier decades.

Evolution of Canada's Boreal Forest Spatial Patterns as Seen from Space.

Understanding the development of landscape patterns over broad spatial and temporal scales is a major contribution to ecological sciences and is a critical area of research for forested land management. Boreal forests represent an excellent case study for such research because these forests have undergone significant changes over recent decades. We analyzed the temporal trends of four widely-used landscape pattern indices for boreal forests of Canada: forest cover, largest forest patch index, forest edge density, and core (interior) forest cover. The indices were computed over landscape extents ranging from 5,000 ha (n = 18,185) to 50,000 ha (n = 1,662) and across nine major ecozones of Canada. We used 26 years of Landsat satellite imagery to derive annualized trends of the landscape pattern indices. The largest declines in forest cover, largest forest patch index, and core forest cover were observed in the Boreal Shield, Boreal Plain, and Boreal Cordillera ecozones. Forest edge density increased at all landscape extents for all ecozones. Rapidly changing landscapes, defined as the 90th percentile of forest cover change, were among the most forested initially and were characterized by four times greater decrease in largest forest patch index, three times greater increase in forest edge density, and four times greater decrease in core forest cover compared with all 50,000 ha landscapes. Moreover, approximately 18% of all 50,000 ha landscapes did not change due to a lack of disturbance. The pattern database results provide important context for forest management agencies committed to implementing ecosystem-based management strategies.

Correction: Effects of Climate Change on Habitat Availability and Configuration for an Endemic Coastal Alpine Bird.

[This corrects the article DOI: 10.1371/journal.pone.0142110.].

Effects of Climate Change on Habitat Availability and Configuration for an Endemic Coastal Alpine Bird.

North America's coastal mountains are particularly vulnerable to climate change, yet harbour a number of endemic species. With little room "at the top" to track shifting climate envelopes, alpine species may be especially negatively affected by climate-induced habitat fragmentation. We ask how climate change will affect the total amount, mean patch size, and number of patches of suitable habitat for Vancouver Island White-tailed Ptarmigan (Lagopus leucura saxatilis; VIWTP), a threatened, endemic alpine bird. Using a Random Forest model and a unique dataset consisting of citizen science observations combined with field surveys, we predict the distribution and configuration of potential suitable summer habitat for VIWTP under baseline and future (2020s, 2050s, and 2080s) climates using three general circulation models and two greenhouse gas scenarios. VIWTP summer habitat is predicted to decline by an average of 25%, 44%, and 56% by the 2020s, 2050s, and 2080s, respectively, under the low greenhouse gas scenario and 27%, 59%, and 74% under the high scenario. Habitat patches are predicted to become fragmented, with a 52-79% reduction in mean patch size. The average elevation of suitable habitat patches is expected to increase, reflecting a loss of patches at lower elevations. Thus ptarmigan are in danger of being "squeezed off the mountain", as their remaining suitable habitat will be increasingly confined to mountaintops in the center of the island. The extent to which ptarmigan will be able to persist in increasingly fragmented habitat is unclear. Much will depend on their ability to move throughout a more heterogeneous landscape, utilize smaller breeding areas, and survive increasingly variable climate extremes. Our results emphasize the importance of continued monitoring and protection for high elevation specialist species, and suggest that White-tailed Ptarmigan should be considered an indicator species for alpine ecosystems in the face of climate change.

Long-term changes in river-floodplain dynamics: implications for salmonid habitat in the Interior Columbia Basin, USA.

Rivers and their associated floodplains are among the world's most highly altered ecosystems, resulting in billions of dollars in restoration expenditures. Successful restoration of these systems requires information at multiple spatial scales (from localized reaches to broader-scale watersheds), as well as information spanning long time frames. Here, we develop a suite of historical landscape indicators of riverine status, primarily from the perspective of salmonid management, using a case study in the Interior Columbia Basin, Washington, USA. We use a combination of historical and modern aerial photography to quantify changes in land cover and reach type, as well as potential fish habitat within channel and off-channel floodplain areas. As of 1949, 55% of the Wenatchee River floodplain had been converted to agriculture. By 2006, 62% had been modified by anthropogenic development, of which 20% was due to urban expansion. The historical percentage of agricultural land in the watershed and the contemporary percentage of urban area surpass thresholds in land cover associated with deleterious impacts on river systems. In addition, the abundance of reach types associated with the highest quality salmonid habitat (island braided and meandering reaches) has declined due to conversion to straight reach types. The area occupied by fish habitats associated with channel migration (slow/stagnant channels and dry channels) has declined approximately 25-30%. Along highly modified rivers, these habitats have also become increasingly fragmented. Caveats related to visual quality and seasonal timing of historical photographs were important considerations in the interpretation of changes witnessed for headwater island braided systems, as well as for floodplain ponds. Development of rigorous, long-term, multi-scale monitoring techniques is necessary to guide the management and restoration of river-floodplain systems for the diversity of ecosystem services they provide.

Merging aquatic and terrestrial perspectives of nutrient biogeochemistry.

Although biogeochemistry is an integrative discipline, terrestrial and aquatic subdisciplines have developed somewhat independently of each other. Physical and biological differences between aquatic and terrestrial ecosystems explain this history. In both aquatic and terrestrial biogeochemistry, key questions and concepts arise from a focus on nutrient limitation, ecosystem nutrient retention, and controls of nutrient transformations. Current understanding is captured in conceptual models for different ecosystem types, which share some features and diverge in other ways. Distinctiveness of subdisciplines has been appropriate in some respects and has fostered important advances in theory. On the other hand, lack of integration between aquatic and terrestrial biogeochemistry limits our ability to deal with biogeochemical phenomena across large landscapes in which connections between terrestrial and aquatic elements are important. Separation of the two approaches also has not served attempts to scale up or to estimate fluxes from large areas based on plot measurements. Understanding connectivity between the two system types and scaling up biogeochemical information will rely on coupled hydrologic and ecological models, and may be critical for addressing environmental problems associated with locally, regionally, and globally altered biogeochemical cycles.