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Ekologi dan Analisis SDA TKW 128
PERTEMUAN 2 Konsep Dasar Landscape Ekologi SUPRAJAKA Fakultas Teknik Universitas Indonusa Esa Unggul
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(from Bissonnette 1997)
Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan? 1) Broad-scale ecosystem processes can be slow and/or infrequent.
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Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan? 1) Broad-scale ecosystem processes can be slow and/or infrequent. 2) To improve our understanding of ecosystem stability and resilience – natural variability.
Ecological Stability and Resilience
Stabilitas dan Ketahanan Ekosistem
Ecosystems: closed vs. open deterministic vs. stochastic homogeneous vs. heterogeneous
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Variabilitas Alam • Understanding and maintaining dynamic ecosystems. • Spatial and temporal variation in ecological conditions, that are relatively unaffected by people, within a period of time and over a geographical area (Landres et al. 1999). • Assumptions: 1) Disturbance is an natural part of any ecosystem, 2) Ecosystems are resilient to disturbance, 3) Maintaining ecosystem types maintains ecosystem integrity, over broad spatial scales.
Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan? 1) Broad-scale ecosystem processes can be slow and/or infrequent. 2) To improve our understanding of ecosystem stability and resilience – natural variability. 3) To improve our predictions of future ecosystem states.
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Complex Systems Theory
Ecological systems are complex and often dependent on initial conditions. •
Sistem ekologi yang kompleks dan sering bergantung pada kondisi awal
Legacies – structures that affect ecosystem functioning long after disturbance event. •
Warisan - struktur yang mempengaruhi fungsi ekosistem lama setelah terjadi gangguan.
Message from a Mountain -- Franklin and MacMahon (2000) Ecosystem Recovery
Extant Theory Predicted
Actually Occurred
• Slow • Uniform encroachment by hardy species • Ecological Succession
• Rapid • Via diverse pathways: largely nucleation • Largely due to legacies
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Biotic Legacies – jenis, jumlah, atau pola organisme dan struktur biotik yang bertahan dari ekosistem pra-gangguan. Biotic Legacies of Mt. St. Helens: • rhizomes, roots, seeds, and spores below ground • rimpang, akar, biji, dan spora di bawah tanah • tree saplings and shrubs • anakan pohon dan semak-semak • invertebrates and amphibians in ponds • Invertebrata dan amfibi di kolam • snags and downed logs • Snags dan log jatuh
Biotic Legacies – jenis, jumlah, atau pola organisme dan struktur biotik yang bertahan dari ekosistem pra-gangguan. ABiotic Legacies of Mt. St. Helens: • ash deposition • mud slides and erosion channels
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Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan? 1) Broad-scale ecosystem processes can be slow and/or infrequent. 2) To improve our understanding of ecosystem stability and resilience – natural variability. 3) To improve our predictions of future ecosystem states. 4) To provide background for natural resources management decisions.
Ecological Restoration •
Requires defensible baselines.
•
Baselines are used to: 1)
assess the need for restorative treatments, and
2)
to evaluate their success.
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Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan? 1) Broad-scale ecosystem processes can be slow and/or infrequent. 2) To improve our understanding of ecosystem stability and resilience – natural variability. 3) To improve our predictions of future ecosystem states. 4) To provide background for natural resources management decisions. 5) General interested in where we have been
Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan?
•The Environmental Record • Lake Sediments, Bogs, Forest Hollows • Tree Cores • Packrat middens • Field evidence
• The Written Record • Land Surveys, Wills, Tax Rolls • Aerial Photos, Maps, Landscape Photos • Laws, Diaries, Artwork
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Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan? Lake Sediments, Bogs, Forest Hollows
Palynology – species, not communities, migrate (Davis 1981)
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Why study historical landscapes? Mengapa Mempelajari Sejarah Bentanglahan? • Tree Cores
Land Surveys – some uses and insightsB • Determining the ecological niche of tree species (Whitney 1982) • Determine fire regime in even-aged systems (Radeloff et al. 1999) • Baseline in documenting land cover change (White and Mladenoff 1996) • Baseline for ecological restoration (Parker 1997)
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Presettlement (1860s) – Public Land Surveys Process: Broad-scale human disturbance
Post-settlement (1930s) – Wisconsin Land Economic Inventory
Process: Forest succession
Current (1989) – Color infrared Aerial photos
All Data Sources have Strengths and Limitations!!! • Environmental Record • Pollen of some species over/under represented due to differences in dispersal or preservation. • Extreme events can erase a previously recorded event. • Written Record • Bias or self-interest of observer. • Knowledge of the observer. • Context of the statement.
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Multi-data Source •
Moore, et al. (1999) use historical data to determine reference conditions in Southwestern Ponderosa Pine Forests: Fire regime
Dendrochronology
Vegetation composition
Pollen Data
Vegetation structure
Dendrochronology, Historical records & photos Pack rats
Beberapa hal penting yang telah kita pelajari sejarah bentanglahan Ekosistem TIDAK statis, deterministik, homogen, atau ditutup. Spesies, bukan komunitas, bermigrasi latitudinally dan elevationally dengan perubahan iklim. Warisan biotik dan abiotik dari gangguan dapat memiliki efek berkepanjangan pada komposisi ekosistem, fungsi, dan struktur. Penggunaan lahan manusia dapat memiliki besar dan terus-menerus mempengaruhi pada pola vegetasi dan kualitas sungai. Merekonstruksi rezim gangguan. Dan masih banyak lagi ....
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Climatologists Ecologists
Historians
Historical Ecology Landscape Architects
Managers Geographers
TERIMAKASIH.....................
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