Standardizing and Categorizing Tree Growth Models

Pretzsch, Hans; Biber, Peter; Ďurský, J.; Gadow, Klaus von; Hasenauer, Hubert; Kändler, Gerald; Kenk, G.; Kublin, Edgar; Nagel, Jürgen G.; Pukkala, Timo; Skovsgaard, Jens Peter; Sodtke, Rainer; Sterba, Hubert

doi:10.1007/3-540-31304-4_3

Cited by 4 publications

(4 citation statements)

References 24 publications

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“…large amounts of data from silvicultural trials or operational inventories in a way that allows the user to explore the consequences of alternative treatments and regimes through simulation (Pretzsch et al 2006). However, empirical models are more or less limited to the range of conditions represented in available data and generally consider site quality invariant.…”

Section: Introductionmentioning

confidence: 99%

A hybrid model for intensively managed Douglas-fir plantations in the Pacific Northwest, USA

2009

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Recent advances in traditional forest growth models have been achieved by linking growth predictions to key ecophysiological processes in a hybrid approach that combines the strengths of both empirical and process-based models. A hybrid model was constructed for intensively managed Douglas-fir plantations in the Pacific Northwest, USA, by embedding components representing fundamental physiological processes and detailed tree allometrics into an empirical growth model for projecting individual tree and stand development. The simulated processes operated at a variety of scales ranging from individual branches to trees and stands. The canopy structure submodel improved predictions of leaf area index at the stand level when compared to allometric and other empirical approaches (reducing mean square error by 30-42%). In addition, the hybrid model achieved accuracy in short-term volume growth prediction comparable to an empirical model. Biases in 4-year stand growth predictions from the hybrid model were similar to those from the empirical model under thinning, fertilization, and the combination of these treatments; however, volume growth predictions in unmanaged plantations averaged approximately 36% less bias. These improvements were attributed to detailed information on crown structure (i.e. size, location, and foliage mass of primary branches), simple representation of key physiological processes, and improved site characterization. Soil moisture, temperature, and nitrogen mineralization predicted by the hybrid model also agreed closely with observed values from several previous studies. Overall, the model framework will be helpful for future analyses as it can lend insight into the influence of weather and site edaphic factors on growth, help identify mechanisms of response to silvicultural treatments, and facilitate the design of sound management regimes for Douglas-fir plantations across the Pacific Northwest region.

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Section: Introductionmentioning

confidence: 99%

A hybrid model for intensively managed Douglas-fir plantations in the Pacific Northwest, USA

2009

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“…The purpose of data acquisition and modelling for decision making may be classified as, e.g., scenario studies of silviculture, updating of forest stand information, updating of larger assessment units, instruction and control, professional training, and research (Pretzsch et al 2006). In the case of forest regeneration, the three alternative sources for data acquisition used in modelling have been controlled regeneration experiments, collection of regeneration data as part of a routine forest inventory, and operational regeneration surveys or inventories .…”

Section: Introductionmentioning

confidence: 99%

Quality management of forest regeneration activities

Kankaanhuhta¹

2014

Diss. For.

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The purpose of this thesis was to find out what are the main factors that have to be taken into account in planning, controlling and improving the quality of forest regeneration activities. The forest regeneration services provided for the non-industrial privately-owned forests in Southern Finland by the local Forest Owners' Associations (FOAs) were used as an example. Since the original assumptions of quality management were not completely valid in this context, Lillrank's classification of production processes was used. The classification fit well for this field of services, and a tentative framework for modelling and standardisation of forest regeneration service processes was proposed for further testing. The results of regeneration and costs varied considerably between the service providers at different levels. The jointly analysed inventory results and feedback provided a sound starting point for tackling the main causes of the statistical variation observed. The inventory results indicated that the selection of proper methods of regeneration and the way they were executed were the most common factors influencing the quality of service outcomes. The cost-quality analysis of the two most common chains of regeneration revealed an improvement potential for the cost-efficiency of these services. In the case of Norway spruce (Picea abies (L.) Karst.) planting the regeneration costs were only weakly related to quality. As for direct seeding of Scots pine (Pinus sylvestris L.) direct seeding, a significant positive correlation was found. However, the selection of this chain of regeneration for the MT (Myrtillus type) and more fertile site types produced poor regeneration results. In the case of Norway spruce planting, the most important factor explaining the outcomes was soil preparation. Selection of mounding produced better results than patching and disc trenching. In the FOAs, the effect of quality management interventions was observable especially regarding the improvement of resource allocation and practices related to soil preparation. Keywords TIIVISTELMÄTutkimuksen päämääränä oli selvittää korkealaatuiseen metsänuudistamistulokseen tähtäävän uudistamistoiminnan suunnittelussa, hallinnassa ja kehittämisessä vaadittavat tekijät. Esimerkkinä toimivat Etelä-Suomen yksityismetsiin metsänuudistamispalveluja tuottavat metsänhoitoyhdistykset. Koska laatujohtamisen perusoletukset eivät olleet kaikilta osin päteviä yksityismetsien uudistamistoiminnassa, käytettiin apuna Lillrankin kehittämää tuotantoprosessien luokittelua. Tämä luokitus soveltui hyvin tutkittavien palvelujen kehittämiseen, ja sen pohjalta luotiin alustava kehittämismalli metsänuudistamisen palveluprosessien mallinnukseen ja vakiointiin. Tutkimustulokset paljastivat merkittävää vaihtelua sekä uudistamistuloksissa että palvelujen kustannuksissa eri toimijoiden välillä. Yhdessä analysoitu palaute laatuinventoinneista mahdollisti kehittämistyön, jossa keskityttiin merkittävimpien tilastollista vaihtelua aiheuttavien tekijöiden hallintaan. Merk...

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“…In this perspective, we define models as quantitative tools that predict the future probability distribution of an ecological variable, conditional upon initial conditions, parameter distributions, distributions of extrinsic drivers, and the choice of mathematical or statistical methods used to make the calculations (Carpenter 2002). Simulators, on the other hand, refer to computer programs resulting from the conversion of such models into a piece of software for scenario calculation, and often visualization (Pretzsch et al 2006).…”

Section: Introductionmentioning

confidence: 99%

“…The state-of-the-art in forest ecosystem modeling has been presented in several conferences (e.g., Fries 1974, Ek et al 1988, Burkhart et al 1989, Dixon et al 1990, Wensel & Biging 1990, Amaro & Tomé 1999, Rennols 2001, LeMay & Marshall 2003, Hasenauer & Mäkelä 2005, and much of the accumulated knowledge is summarized by textbooks (Dudek & Ek 1980, Dixon et al 1990, Solomon & Shugart 1993, Vanclay 1994, Mladenoff & Baker 1999, Von Gadow & Hui 2001, Thornley & Johnson 2002, Amaro et al 2003, Grimm & Railsback 2005, Hasenauer & Mäkelä 2005, Hasenauer 2006, Pretzsch et al 2006, Voinov et al 2008, Pretzsch 2009). The diversity in ecosystem processes has resulted in the development of an extraordinary array of different models in forest ecology and management.…”

Section: Introductionmentioning

confidence: 99%

Modeling Italian forests: state of the art and future challenges

Vacchiano¹,

Magnani²,

Collalti³

2012

iForest

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This review is a follow-up to the first meeting of the Forest modeling working group (FMWG) of the Italian Society of Silviculture and Forest Ecology (SISEF), held in December 2009. 18 talks were delivered to an audience of 40 researchers. We review the state of the art of forest ecosystem modeling in Italy, highlight findings from Italian research groups, and summarize relevant issues. Developing on the discussion session of the meeting, we indicate current research gaps and future challenges for modelers, forest ecologists and foresters alike, with a special emphasis on model validation, data availability, and communication between researchers and managers.

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Standardizing and Categorizing Tree Growth Models

Cited by 4 publications

References 24 publications

A hybrid model for intensively managed Douglas-fir plantations in the Pacific Northwest, USA

A hybrid model for intensively managed Douglas-fir plantations in the Pacific Northwest, USA

Quality management of forest regeneration activities

Modeling Italian forests: state of the art and future challenges

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