Forest dynamics: disturbances and succession part 2

Forest disturbance dynamicsDisturbances
Disturbances
Biomass Hydrology Topography Biogeochemistry
Disturbances
Forest successional patterns
Forest successional patterns
• Concepts and terminology
• Research of disturbance dynamics
of the hazard
susceptible to the hazard
Occurrence
for some elements
Photo credits: redwhortleberry.blogsport.co.uk.html
– Absent – Seldom – Infrequent – Often
– Absent – Seldom – Infrequent – Often
A S I O
Estonian forest site types
e
arid
humid
Nutrients
MÄND – Pinus sylvestris KUUSK – Picea abies SOOKASK – Betula pubescens SANGLEPP – Alnus glutinosa
Nõmmemets Loomets
Disturbance impact
of the hazard
susceptible to the hazard
Occurrence
for some elements
Fire – species susceptibility, adaptation
Serotinous species: species with an ecological adaptation to release seeds in response to an environmental trigger – usually in literature fire (pyriscence)
World: - Protaeceae - Eucalyptus - Erica - Cupressus - Pinus - Picea - Sequoiadendron
Europe: - Pinus
- Cupressus sempervirens
Surface fire
Crown fire
Tree – Species Size (height, diameter, development of crown and root system) Position (within the stand, vertically & horizontally, substrate) Age Vigour/vitality Surrounding trees and vegetation
Stand – Single tree susceptibility (above-mentioned features) Composition Development stage Position (geographical, topographical, aspect) Surrounding stands/areas
Landscape – Single tree and stand susceptibility (above-mentioned features) Land use Heterogeneity
General
What makes a tree more or less susceptible to disturbance?
Stand – Single tree susceptibility (above-mentioned features) Composition Development stage Position (geographical, topographical, aspect) Surrounding stands/areas
General
… what makes a stand more or less susceptible to disturbance?
Stand – Single tree susceptibility (above-mentioned features) Composition, canopy structure Development stage Position (geographical, topographical, aspect) Surrounding stands/areas
General
• Climate and meteorological conditions • Management • Disturbance characteristics (duration, intensity) • Disturbance history • Etc!
… and what makes a landscape more or less susceptible to disturbance?
Stand – Single tree susceptibility (above-mentioned features) Composition, canopy structure Development stage Position (geographical, topographical, aspect) Surrounding stands/areas
General features affecting disturbance impact
• Climate and meteorological conditions • Management • Disturbance characteristics (duration, intensity) • Disturbance history • Etc!
Disturbance impact
of the hazard
• Probability analysis • Risk analysis
for some elements
Homogeneously planted forests with high volume of growing stock are
sensitive to wind damage
Credits: STORMRISK project Interreg IIIB 2000-2006
Polish forest zones at risk of insect outbreaks (total - primary and secondary) (source: FRI)
Herbivores
Stages of forest successional development
Timing and magnitude of the disturbance
shade-intolerant species
shade-tolerant species
Shift in dominance late-successional species
Fig. 1. Proposed models for the relationship between disturbance severity and forest tree species composition. Note that in the cusp model, sudden change would occur for any disturbance with severity beyond the edge of the cusp, in which case, composition would jump downward or upward. The shaded part of the curve is inaccesible. http://www.ecologyandsociety.org/vol2/ iss2/art7/ Frelich & Reich 1998 – Ecology & Society
Tree recruitment (seedling and sapling banks)
Vegetatively reproducing parts
Mature and immature animals and microbes
Organic matter Fine litter
Downed trees and other coarse woody debris
Root plates (mounds) and pits from uprooted trees
Organically derived patterns Soil chemical, physical and microbial properties
Forest understory composition and distribution
Disturbance legacies
Complexity
The intermediate disturbance hypothesis. The greatest biological diversity is expected to occur at intermediate levels of disturbance (modified from Connell 1978).
DISTURBANCES FREQUENT INFREQUENT
DISTURBANCE LARGE SMALL
Ecosystem resilience
Marten 2001 – Human Ecology – Basic concepts for sustainable development - Ch. 6 - Ecological succession
→ the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and recovering relatively fast
Carrying capacity
Franklin, Shugart & Harmon 1987 – Bioscience
Interaction between disturbances
Traditional fire fighting in Estonia
Source: IFFN 2004
• Including natural processes
• Salvage logging
• Species composition
Kuuluvainen & Grenfell, 2012, Natural disturbance emulation in boreal forest ecosystem management — theories, strategies, and a comparison with conventional even-aged management
Advance regeneration
Research on disturbance dynamics
• Purpose, financers, perspective
• Pathogens and insects
• Pathogens and insects
Conference website
Forest disturbance dynamics 6. November – 11 December 2017 Seminar room 2B20 10:00 - 12:00
Lectures by topic
Lecture 1 – Introduction to the course – Herbivores: ungulates 6 November – Marek Metslaid
Lecture 2 – Wind 13 November – Jeroen Engelhart
Lecture 3 – Pathogens and insects 20 November – Tiia Drenkhan
Lecture 4 – Fire, carbon balance 27 November – Kristi Parro
Lecture 5 – Herbivores, ecosystem engineers: beavers 4 December – Petri Nummi
Lecture 6 – Interactions of disturbances, human interference, climate change, future perspectives 11 December – Kalev Jõgiste, Floor Vodde
Register before the start of the course: [email protected] or [email protected]

Documents

Forest dynamics: disturbances and succession part 2