teaching forest stand dynamics
DESCRIPTION
This presentation provides an overview of a field-based practical exercise that allows students in forestry, ecology and natural resources to develop their understanding of forest stand dynamics. The exercise involves measurement of key tree growth parameters in four even-aged, single-species plantation stands of different age but occupying sites with similar soil and environmental characteristics. The selected stands represent key stages in stand development, from establishment to rotation age for fibre production. In the field, students work in small teams to gather data from an equal number of plots within each stand. Tree parameters include top height, crown diameter, live crown ratio and diameter at breast height. In addition, information on stand density and understorey vegetation is collected. Plot size and number can be varied to suit the constraints of class size and available time, though circular plots of 100 m2 are recommended. In the classroom, data are pooled and analysis focuses on presenting tree and vegetation changes through time. The simplest way of interpreting the data is to prepare graphs and charts for each of the parameters, though more advanced statistical interpretations are possible. The project as outlined here can be modified to meet the needs of different groups, and has been successfully used in undergraduate teaching of silviculture and forest ecology, as well as in postgraduate courses in natural resources management. Download Paper at URL: http://www.researchgate.net/publication/254307252_The_development_of_even-aged_plantation_forests_an_exercise_in_forest_stand_dynamicsTRANSCRIPT
Professional Forestry Education
Fundamentals of Forest Stand Dynamics:
An approach to experiential learning for forestry students
Edward WilsonSilviculturist
Scottish School of Forestry
Inverness College UHI, Inverness, Scotland
18 July 2014
First presented: 18 07 2014This version: v1.1, 18 07 2014
RESEARCH
I N T E R N A T I O N A L
Outline
• Definition and relevance of Forest Stand Dynamics to forestry education
• Organisation and approach to a learning session/activity– Experiential
– Integrative
– Active
• Learning outcomes from completion of the session
• Questions and Discussion
Forest Stand Dynamics (1)
• What is Forest Stand Dynamics?
– The study of change in forest stand structure with time, including stand behaviour during and after disturbance (human-caused or natural)
– Oliver and Larson 1996
• What are the Foundations of the Discipline of Forest Stand Dynamics?
– Observation
– Ecology, physiology, morphology, anatomy, environmental factors
– Facilitates study of Interactions – i.e., tree-tree, species-species, tree-site
– Enables understanding of Stand Growth and Succession
• Where does Forest Stand Dynamics fit in the undergraduate forestry curriculum?
– Forest science
– Silvicultural systems
– Woodland ecology
– (Re-enforces learning in Forest mensuration and thinning control, and other modules)
Forest Stand Dynamics (2)
• Why is Forest Stand Dynamics important for foresters?
– Aids understanding of forest development and responses to natural disturbance
– Basis for understanding the interactions and responses to planned interventions
• Predicting productivity and future yield
• Predicting future structure and composition
• Controlling silvicultural costs
• Habitat and conservation values
• Enhancing landscape-scale values
– Forests are complex systems and need to be managed to be both resilient (to minimise effects of climate change, pests and diseases) and sustainable (social, economic, ecological and environmental factors)
– Principles of forest stand dynamics apply to all forest types and forest biomes.
Development stages in a natural forest
initial stage intermediate stage final stage
Strategies for Enhancing Forest Resilience
Modify thinning regimes Extended “rotations”
Diversify stand structures(i.e., CCF)
Species choice- genetics/provenance
Mixed species
Assisted migration of native species
New species introduced
Wider use of “minor” species
Diagram based on Oliver and Larsen 1996Adapted from graphic by Jens Haufe
openground
1. Stand initiation 2. Stem exclusion 3. Understorey re-initiation 4. Old growth
Intervention Options linked to Enhanced Resilience
Modify harvesting systems
Facilitating Learning in Forest Stand Dynamics
• Exercise designed to demonstrate theory through an experiential learning model
• Wilson and Leslie 2008 Journal of Biological Education 42(4): 170-176
• Selected for the Routledge special collection of 100 scientific papers to celebrate the UN International Year of Forests, 2011
• Successfully applied and tested with First Year HE forestry learner groups
• Learning activity in 2 parts (each 3 hours):
– Part 1 – Field (Site inspection and data collection)
– Part 2 - data collation, presentation, analysis and interpretation
Session 1: Site inspection and data collection (Field Based) (3 hours)
Identify 4 stands in close proximity but at different stand ages
Greystoke Forest, near Penrith, Cumbria
Stand 1 Stand 2 Stand 3 Stand 4
Stand location (OS Grid Ref.) NY 387 346 NY 388 345 NY 393 340 NY 389 342
Stand age (years) 3 12 30 45
Altitude (m) 260 260 255 265
Aspect NE NE NE NE
Topography Gentle slope Gentle slope Lower slope Upper slope
Soil type Acid brown earth Acid brown earth Acid brown earth Acid brown earth
Soil texture Loamy clay Loamy clay Loamy clay Loamy clay
Rooting depth (cm) ~ 30 ~30 ~30 ~30
Wind hazard classification 4 4 3 4
Rotation Re-stocked Re-stocked Re-stocked First
Site preparation Mounded Mounded Ploughed Turf planted
Thinning Unthinned Unthinned
Row thinning (1-in-6 rows)
at 20 yrs.Low thinning
at 28 yrs.
Unthinned
Initial density (stems/ha) 2200 2200 2000 3700
Current density (stems/ha) 2200 2100 900 1800
Summary of stand characteristics
Basic measurements
• Health and Safety, Risk Assessment completed and explained
• PPE provided
• Learners work in small groups
• Each group visits each site/stand
• Complete measurements in 100m2 or 200 m2 plots (trees and ground vegetation)
• Follow standard protocol and submit data to session facilitator
Session 2: Analysis and Interpretation (3 hours)
• Introduction (10 mins)
– Outline the learning goals, objectives and structure of the session
– Review and reflect on key aspects of session 1
• FastFacts Lecture (20 mins)
– Theory, terminology
• Explain the task (10 mins)
– Distribute handout and data sheets
– Explain steps required to complete the exercise
• Student Activity (in groups of 2-3) (90 mins)
– Summarise and collate data
– Present results in graphical format
– Create a stand profile diagram
• Review and reflect (30 mins)
– Group and class discussion
– Review of learning outcomes and reflect on application of knowledge to forestry practice
Summary results (means)
Tree and Stand Parameters
Stand 1 Stand 2 Stand 3 Stand 4Mean top height (m) 0.3 4.5 22.4 23.7Mean live crown (%) 98 97 48 39Mean DBH (cm) 0 7.1 23.2 22.0Mean crown diameter (m) 0.3 2.0 2.8 2.2Basal area (m2/ha) 0 8 38 68
Ground Vegetation (Relative Abundance – Domin Scale)
Stand 1 Stand 2 Stand 3 Stand 4
1. Grasses 8 6 2 0
2. Woody plants 4 0 0 0
3. Non-woody plants1 4 8 5 4
4. Needles/tree litter 4 4 9 10
5. Bare soil 4 0 0 01 The dominant species in this group were mosses.
0
20
40
60
80
100
0 10 20 30 40 50
Mean liv
e c
row
n (
%)
0
5
10
15
20
25
0 10 20 30 40 50
Mean top h
eig
ht (m
)
0
5
10
15
20
25
30
0 10 20 30 40 50
Stand Age (years)
Mean D
BH
(cm
)
Grand
period
a.
b.
c.
Presentation of Tree and Stand Relationships 1. Best-fit Line Graphs
a. Mean Top Height versus Stand Age
b. Mean Live Crown Ratio versus Stand Age
c. Mean DBH versus Stand Age
Presentation of Tree and Stand Relationships2. Stand Profile Diagrams
Diagram can be annotated so that key features at each development stage are identified
Activities and learning outcomes associated with completion of the exercise (1)
Activity Learning outcomesUnderstanding silvicultural relationships
Understanding the priorities in the allocation of photosynthate
Relating the processes of self-thinning and competition to even-aged stands
Recognising the stages in the development of even-aged stands
Measurement of stand parameters
Understanding fundamental tree parameters Use of mensuration equipment Basic maths (calculating heights from % and
distance, live crown percent) Ecological survey methods (quadrats and measures
of abundance) Identification of ground vegetation
Laying out plots Understanding of sampling Calculation of areas
Activities and learning outcomes associated with completion of the exercise (2)
Activity Learning outcomesRecording field data Use of forms
Recording data legibly, neatly, accuratelySummarisation of data Use of calculators, spreadsheets
Understanding of basic statistics (mean values, but more advanced analysis possible depending on the group)
Preparation of graphs Use of chart function in spreadsheets Understanding the labelling and other
requirements of graphsInterpretation of graphs Relating field experience to quantitative data
Understanding of the influences of age and stocking on stand and tree parameters
Describing the main results Scientific writing skills Referencing
Professional competencies Working in a team Critical reasoning Organising work
Professional Forestry Education
Reference
Wilson, E. R., and A. D. Leslie. 2008. The development of even-aged plantation forests: a field-based practical exercise in forest stand dynamics. Journal of Biological Education 42(4): 170-176URL: http://silviculture.org.uk/publications/ Download: http://www.researchgate.net/profile/Edward_Wilson5
First presented: 18 07 2014This version: v1.1, 18 07 2014
Contact Information
Edward Wilson
Email: [email protected]
Web: www.silviculture.org.uk
RESEARCH
I N T E R N A T I O N A L