•Regrowth forest is important biodiversity habitat when little mature forest remains.•Identifying regrowth with mature forest elements can guide strategic reservation.•Stand maturity related weakly ...to remote-sensed and measured environmental variables.•Eucalypt crown senescence weakly indicates stands likely to contain habitat trees.•Timber production and conservation are not in conflict on more productive sites.
In this study, we examined the associations between field-assessed floristic and structural habitat values for mature forest and GIS-derived variables to assess whether high conservation value forests could be predicted for strategic reservation at a landscape scale. We investigated the Eucalyptus regnans forests of the Victorian Central Highlands in south-eastern Australia, where several extensive wildfires in the last century have left little mature forest. We assessed the extent to which the floristic composition and a suite of habitat-related structural variables could be explained by two forest inventory GIS variables (percentage senescence and site productivity) and whether explanatory capacity improved from inclusion of additional environmental variables (climate, soils, topography, structure and spatial location). Results showed that the floristic composition was weakly related to productivity, but not to percentage senescence. Four habitat-related structural variables were positively related to percentage senescence (density of old-growth eucalypts, the quadratic mean diameter (QMD) of both live and dead eucalypts, and the maximum eucalypt form class (a proxy for tree hollows)) while the volume of CWD had a marginally significant positive relationship. Three structural variables were related to productivity (the maximum eucalypt form class, the QMD of dead understorey trees and of dead eucalypts). However, in all cases the explanatory power of percentage senescence and productivity was weak (proportion of deviance explained by the models <0.3). Inclusion of the other environmental variables did not substantially improve explanatory power in any case. Our results suggest that there is a high degree of stochasticity driving floristic and structural composition within these forests, making the detection of most mature forest values difficult without site visits. There may be some limited capacity for the presence of senescent trees visible in aerial photographs to highlight stands more likely to contain habitat trees, but there was no relationship with floristic maturity. Our results also suggest that more productive sites do not have substantially greater habitat values, indicating that the current timber harvesting approach of prioritising the harvest of stands on more productive sites is unlikely to have negative consequences for biodiversity.
Primary forests provide critical climate regulation functions through the capture and storage of carbon in biomass reservoirs. The capacity of primary forests to sustain biomass levels and the ...possible consequences of warming-induced increases in extreme disturbances are unresolved questions. We investigated the drivers of biomass accumulation in European primary mountain forests in the Carpathians. We used inventory datasets from a continental-scale survey of remnant primary forests to quantify levels of aboveground live and dead biomass across mixed beech and spruce forest types. We formulated nonlinear regression models to estimate the effects of abiotic and biotic factors, including plot-level disturbance history and tree age using dendrochronological methods. Our analyses show that biomass stocks are comparable with stocks present in other primary forests of temperate regions. Highest mean total biomass in mixed beech forests was in southern landscapes (491 ± 81 Mg ha
−1
) and western for spruce forests (388 ± 106 Mg ha
−1
). Forests maintained positive biomass accumulation rates over centuries-long time frames, mean plot-level age peaking at ~ 225 years. We demonstrate that primary forests continue to function as carbon sinks at older ages. Preserving the integrity of unmanaged forests serves as an important climate mitigation strategy.
1. Maintaining developmental heterogeneity of ecological communities within landscapes is crucial for sustainable native forest management. Consequently, methods to assess forest maturity (i.e. the ...degree to which the forest contains attributes and supports processes characteristic of late-successional forests) are valuable for making management decisions. However, no consistent, pragmatic method to quantify maturity that incorporates multiple ecosystem elements is available for many forest systems, including Australian wet eucalypt forests. 2. We draw upon forest community dynamics theory to develop a method to quantify maturity based on forest attributes, and use this method to create two metrics of wet eucalypt forest floristic and structural maturity. We then test the ability of remotely sensed and field-collected variables to predict these metrics. 3. Both the floristic and structural maturity metrics performed well at capturing underlying trends of forest maturation. Remotely sensed LiDAR (Light Detection and Ranging) and photo-interpretation data provided estimates of moderate accuracy for both floristic and structural maturity (R² = .57-.77). Field variables that are relatively efficient and accurate to measure provided greater model accuracy (R² = .73-.85). Including more complex field variables increased model accuracy to high levels (R² = .93). Therefore, while maturity predicted from remote-sensing data enables a useful and accessible large-scale maturity measure, field indices would provide a more accurate means of assessing maturity at the local stand level. 4. Synthesis and applications. The metrics developed in this study provide a powerful tool for undertaking consistent assessments of wet eucalypt forest maturity. This assessment tool could improve forest management by providing information to optimise practices such as prioritising stands for retention or harvesting, determining the effectiveness of restoration or management practices and monitoring changes in maturity over time. The method could be adapted to any forest system that undergoes well-defined directional development.
This research analyzes how enzymatic and microbiological soil properties relate to site index (SI) and forest maturity (stand age) in Pinus nigra (P. nigra) even-aged forests. The soil parameters ...selected for multivariate analysis were four enzymatic activities (β-glucosidase, urease, dehydrogenase, and alkaline phosphatase), two microbiological properties (microbial biomass C and basal respiration), and five physicochemical parameters (TOC, N, P, pH, and soil water content). We used LiDAR, the digital elevation model, and the terrain model to obtain a result for the dominant height in each plot. The soil parameters were analyzed in the function of five site index classes (8, 11, 14, 17, and 20) and six age classes (50, 70, 90, 110, 170, and 210 years). Our findings emphasize that the dehydrogenase enzyme exhibited variations in response to both the site index and stand age. The activity of dehydrogenase positively correlated with sites characterized by a higher nutrient demand, particularly on young and poor-quality sites (lower SI), indicating activation. Therefore, dehydrogenase could serve as an index to elucidate both site quality and stand development in P. nigra stands, making it a potential indicator of forest ecosystem development.
El trabajo constituye una aproximación conceptual y metodológica para el análisis de la integridad ecológica, como instrumento aplicable a la planificación del territorio y la conservación de la ...naturaleza a escala de paisaje. Con dicho fin se discuten las acepciones de integridad y conceptos próximos y se presenta un modelo de evaluación que considera la integridad del paisaje como resultado de la interacción de tres índices. El primero (integridad espacial) utiliza métricas de la ecología del paisaje (conectividad y cobertura de áreas naturales y áreas de uso humano) y evalúa la distribución de los fragmentos de los distintos tipos de ecosistemas existentes en el territorio. El segundo, un índice de integridad ecosistémica, se centra en los fragmentos con estructura más próxima a la madurez y valora su distancia numérica a ecosistemas de referencia. Por último, en el área sometida a usos agrícolas, se aplica un índice de coherencia ecológica de los usos del suelo que tiene en los elementos naturales con funciones de conservación. Estos índices son articulados mediante un modelo que facilita una visión simultánea de sus valores, así como su comparación con escenarios teóricos. El modelo permite manejar de forma simultánea variables relevantes que comúnmente se presentan como asociadas a aspectos diferentes de la calidad del entorno. Por sus características y escala intermedia de aplicación puede constituir una herramienta importante para enlazar conceptos y actuaciones, relevantes para la conservación de la naturaleza, pero que suelen manejarse por separado, en concreto la integridad ecosistémica y con la planificación del territorio.
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