Spatially dynamic forest management to sustain biodiversity and economic returns.

Production of marketed commodities and protection of biodiversity in natural systems often conflict and thus the continuously expanding human needs for more goods and benefits from global ecosystems urgently calls for strategies to resolve this conflict. In this paper, we addressed what is the potential of a forest landscape to simultaneously produce habitats for species and economic returns, and how the conflict between habitat availability and timber production varies among taxa. Secondly, we aimed at revealing an optimal combination of management regimes that maximizes habitat availability for given levels of economic returns. We used multi-objective optimization tools to analyze data from a boreal forest landscape consisting of about 30,000 forest stands simulated 50 years into future. We included seven alternative management regimes, spanning from the recommended intensive forest management regime to complete set-aside of stands (protection), and ten different taxa representing a wide variety of habitat associations and social values. Our results demonstrate it is possible to achieve large improvements in habitat availability with little loss in economic returns. In general, providing dead-wood associated species with more habitats tended to be more expensive than providing requirements for other species. No management regime alone maximized habitat availability for the species, and systematic use of any single management regime resulted in considerable reductions in economic returns. Compared with an optimal combination of management regimes, a consistent application of the recommended management regime would result in 5% reduction in economic returns and up to 270% reduction in habitat availability. Thus, for all taxa a combination of management regimes was required to achieve the optimum. Refraining from silvicultural thinnings on a proportion of stands should be considered as a cost-effective management in commercial forests to reconcile the conflict between economic returns and habitat required by species associated with dead-wood. In general, a viable strategy to maintain biodiversity in production landscapes would be to diversify management regimes. Our results emphasize the importance of careful landscape level forest management planning because optimal combinations of management regimes were taxon-specific. For cost-efficiency, the results call for balanced and correctly targeted strategies among habitat types.

Testing dependence between growth and needle litterfall in Scots pine--a case study in northern Finland.

Both drought and fungal disease increase needle litterfall of Scots pine (Pinus sylvestris L.) trees, but most factors causing annual variation in needle litterfall are poorly understood. We hypothesized that radial growth and weather conditions favorable to growth correlate positively with needle litterfall with a lag equal to the number of needle cohorts (here being 5-6). We studied the time series of needle litterfall, stem increment, pollen cone litter and daily weather conditions in a Scots pine stand over 43 years (1961-2004). The cross-correlations of standardized time series were estimated with various lags. Model predictions of annual needle litterfall were tested against independent data. Changes in annual growth and needle litterfall correlated with lags of 0 and 4 years. The best predictors for needle litterfall were May to mid July temperature sum with a lag of 4 years, May rainfall with a lag of 2 years and September temperature with a lag of 6 years. Pollen cone litter correlated negatively with needle litterfall with a lag of 2 years. The study provided empirical evidence that needle litterfall of Scots pine in northern Finland is influenced by needle production and needle mass development that occurred 4 to 6 years earlier.

Intra-annual height increment of Pinus sylvestris at high latitudes in Finland.

Intra-annual height growth of Scots pine (Pinus sylvestris L.) in four stands was followed for up to four growing seasons (2000-2003) in the northern boreal zone in Lapland. Elongation of the leader shoot correlated with temperature sum expressed as degree-days. Total length of the leader shoot correlated with growth rate but not with duration of the height-growth period. The longer the annual shoot at the end of the season, the greater the height increment per degree- and growing day. Height-growth cessation was defined as the date when 95% of the total shoot length was achieved. In all stands and all years, height growth ceased when, on average, 41% of the relative temperature sum of the site was achieved (range of variation 38-43%). The relative temperature sum was calculated by dividing the actual temperature sum by the long-term mean for the site. Our results suggest that annual height growth is finished when a location-specific temperature sum threshold is attained.

Modeling of bud break of Scots pine in northern Finland in 1908-2014.

Bud break and height-growth of Scots pine (Pinus sylvestris L.) in the northern boreal zone in Lapland, Finland, was followed through the entire growing seasons in the periods 2001-2003 and 2008-2010 in sapling stands in two different locations in northern Finland set some 250 km apart along a latitudinal transect. Field measurements continued at the southern site also in 2011-2013. Air temperature was recorded hourly at the sites. A simple optimization algorithm (GA) was used to adjust parameters of the models predicting the timing of bud break of Scots pine in order to minimize the difference between observed and predicted dates. The models giving the best performance and century-long daily temperatures were used to reconstruct bud-break time series. The temperature observations were recorded for the period 1908-2014 in Sodankylä, which is located in-between the sapling stands in the north-south direction and for the period 1877-2014 in Karasjok, which is in Norway about 145 km north-west from the northernmost stand of this study. On average buds began to extend in the beginning of May in the southernmost stand and in mid-May in the northernmost stands, and the variation between years was in the range of 3 weeks. A simple day-length-triggered (fixed date) model predicted most accurately the date of bud break; root mean square error (RMSE) was 2 and 4 days in the northern and southern site, respectively. The reconstructed bud-break series indicated that based on temperature observations from Sodankylä, growth onset of Scots pine has clearly advanced since the 1960s, though it currently matches that of the early 1920s and early 1950s. The temperature record from Karasjok indicated a similar variation, though there was a weak linear trend advancing bud break by about 3-4 days over a 100-year period.

The need and total cost of Finnish eyecare services: a simulation model for 2005-2040.

PURPOSE: The aims of this study were: (i) to create a structural simulation model capable of predicting the future need and cost of eyecare services in Finland; and (ii) to test and rank different policy alternatives for access to care and the required physician workforce. METHODS: Using the system dynamics approach, the number and cost of patients with cataract, glaucoma, diabetic retinopathy and age-related macular degeneration (AMD) were described with causal-loop diagrams and were then translated into a set of mathematical equations to build a computer simulation model. Mathematically, the problem was formulated as a set of differential equations that were solved numerically with specialized software. The validity of the model was tested against prevalence and administrative historical data. The costs covered by the public sector in Finland were obtained from 2003 from the Finnish Hospital Discharge Register (including outpatient care), the Finnish Social Insurance Institution and a survey of hospital price lists. Different levels of access to public care were then simulated in four eye diseases, for which the model estimated the need for services and resources and their costs in the years 2005-2040. RESULTS: The model forecasted that the adoption of the 2005 national 'access to care' criteria for cataract surgery would shorten waiting lists. If the workload of Finnish ophthalmologists were kept at the 2003 level, the graduation rate of new ophthalmologists would have to increase by 75% from the current level. If all glaucoma patients were followed in the public sector in future, even this increase in training would not meet the demand for physician workforce. The current model indicated that the screening frequency of diabetes can be increased without large sacrifices in terms of costs. AMD therapy has a significant role in the allocation of future resources in eyecare. The modelling study predicted that ageing alone will increase the costs of eyecare during the next four decades in Finland by about 1% per year in real terms (undiscounted and without inflation of unit costs). The increases in total yearly costs were on average 8.6% between 2001 and 2003. CONCLUSIONS: The results of this modelling study indicate that policy initiatives, such as defining criteria for access to care, can have substantial implications on the demand for care and waiting times whereas the effect of ageing alone was relatively small. Measures to control several other factors - such as the adoption and price level of new technologies, treatments and practice patterns - will be at least equally important in order to restrain healthcare costs effectively.