Sesion 4 - Gustavo Zuleta
Transcripción
Sesion 4 - Gustavo Zuleta
Jornada de Economía Regional, 1-Agosto, Buenos Aires Degradación/restauración de ecosistemas: 1- impactos ambientales mineros, 2- prioridades en Argentina Gustavo Zuleta 1,2 1 Dpto. de Ecología y Ciencias Ambientales, CEBBAD, Universidad Maimónides, Buenos Aires. Argentina. 2 Facultad de Cs. Agrarias, Universidad Nacional de Lomas de Zamora. Argentina. 1 Modelo conceptual Modelo conceptual de degradación y restauración de ecosistemas (Hobbs & Harris 2001) Módulo 1 - Marco conceptual 2 Post-disturbance regeneration thresholds in degraded and rehabilitated semiarid shrublands of the Monte Austral (Northern Patagonia, Argentina) Zuleta, G.A1,2, P. Tchilinguirian1,3,4 , M.L. Castro1, M.E. Ciancio1, A.A. Pérez1, L.G. Reichmann5 , J.Fuchs1,4,6, & C. Escartín1 1 Dept. of Ecology & Environmental Sc., CEBBAD, ISI, Maimónides University, Buenos Aires. 2 Urban Rehabilitation Lab, Faculty of Engineering, National University of Lomas de Zamora, AMBA. 3 Dept. of Geology, Faculty of Natural Sciences, Buenos Aires University, Buenos Aires. 4 National Council of Scientific & Technological Research (CONICET). 5 School of Life Sciences, Arizona State University, Tempe AZ, USA. 6 Dept. of Biological Chemistry, Faculty of Natural Sc., Buenos Aires University, Buenos Aires. 3 Today´s topics The problem: ecosystem degradation. Natural dynamics: the mound cycle. Post-disturbance dynamics: soil-plants-moundsfauna (40 years chronosequence & low-tech experiments). Ecogeomorphic model: thresholds. Rehabilitated dynamics: ¿when/how apply techniques? … ¿low-tech or high-tech? 4 The Problem: ecosystem degradation 5 Worldwide scale Major cause: global economic model of production/consumption. Global Footprint Network (2005) 6 Degradation in Argentina arid/semiarid ecosystems: ca. 140.000.000 ha (50% of the country) Not degraded Extremely degraded Oliva et al. 1995. http://www.fao.org/nr/lada 7 Estepa Patagónica Superficies Ha Total Natural Protegidos Sin uso ni protegidos Humedales Degradada (bajo usos) 1 Ganadería 2 Urbanización 3 Agricultura 4 Cuerpos de agua artificiales 5 Forestación Minería Explotación petrolera % 57.701.512 100,0 5.238.806 2.419.401 1.785.205 1.034.200 9,1 4,2 3,1 1,8 52.462.705 51.943.435 385.850 84.534 40.315 8.572 NA* NA* 90,9 90,0 0,7 0,1 0,1 0,0 NA* NA* * Factores de degradación no cuantificables Libro REA (2014) … en elaboración 8 Argentina´s biodiversity and current ecosystems conditions 9 Argentina´s biodiversity World´s 8th largest country: 2.816.544 km2. 3800-km North-South of environmental gradients. aprox. 4.750 km of marine coastline. 15 terrestrial ecoregions (>35 sub-units). As a result: ranks 10th world highest biodiversity. 385 mammals, ≈1000 birds, 6896 vascular plants .. … high number of endemisms, rare & vulnerable spp. 10 Biodiversity / biome types Subtropical forests (Yungas) Wetlands (Iberá) Temperate grasslands (Pampas) Highlands (Puna) 11 Degradation caused by land use change type km2 country% degraded% 5 grasslands 1.517.480 54 90 6 woodlands 1.010.910 36 50 2 “altitude” 214.588 8 47 2 wetlands 73.567 2 19 100 70 Total 2.816.544 “Ecosystem Restoration Needs in Argentina” (2014) … in preparation 12 Ranking by land use type Degraded (%) 2.000.000 ha Restoration & EIA regulations Cattle raising 68,8 Almost nule Agriculture 29,5 Very low Forestry 0,6 High Urbanization 0,6 Almost nule Mining 0,3 Very high Dams 0,2 Very high Land use Total 100,0 “Ecosystem Restoration Needs in Argentina” (2014) … in preparation 13 Restoration needs Espinal and Pampa´s ecotone: almost gone! … highly threatened ecosystems (Santa Fe & Córdoba) “Ecosystem Restoration Needs in Argentina” (2014) … in preparation 14 Agro-cultural landscapes Pampean grasslands: Argentina´s economic growth 15 ” is restoration feasible? social contraints: “el asadito” 16 Eat or restore? asadito!!!!! 17 RE national priorities project 18 … volviendo a Patagonia … y minería/petróleo 19 Monte (estepa arbustiva) Superficies Ha % Total 35.304.013 100,0 Natural Protegidos Sin uso ni protegidos Humedales 1.8641.865 1.390.325 333.856 117.684 5,2 3,9 1,0 0,3 33.462.148 37.798.681 1.027.951 283.434 195.193 165.888 NA* NA* NA* 94,8 90,0 2,9 0,8 0,6 0,5 NA* NA* NA* Degradada (bajo usos) 1 Ganadería 2 Agricultura 3 Forestación 4 Cuerpos de agua artificiales 5 Urbanización Minería Fuego Disposición de residuos * Factores de degradación no cuantificables Libro REA (2014) … en elaboración 20 Study area: Monte Austral Semi-arid shrub steppes (Northern Patagonia) 21 Degradation factors 1- Oil exploitation 2- Cattle raising Zuleta et al. 2012; Castro et al. 2012 22 Impactos en yacimientos mineros Gentileza Migale & del Valle 23 TESIS DE MAESTRÍA EN MANEJO AMBIENTAL Percepción social del impacto ambiental de la actividad minera en Argentina. Lic. Gabriela Marisa Migale1,2 Director: Dr. Gustavo A. Zuleta 2,3 Codirectora: MSc. Carolina del Valle 1,2 Diciembre 2013 1. URS Corporation S. A. 2. Dpto. de Ecología y Cs. Ambiente, CEBBAD, Universidad Maimónides. 3. Facultad de Ingeniería, Universidad Nacional de Lomas de Zamora (UNLZ). GRAN DINAMISMO DEL SECTOR EN TÉRMINOS MACROECONÓMICOS 25 Se analizó con mayor detalle la categoría “conflicto social” (54/426). 26 27 IDENTIFICACIÓN DE LOS GRUPOS DE INTERÉS RELACIONADOS CON LA ACTIVIDAD MINERA 28 PLANTA PROCESO 29 • PRINCIPALES IMPACTOS AMBIENTALES DE LA MINERÍA Obra /actividad Medio Físico Medio Biológico Medio Social Topografía y recursos hídricos Biodiversidad Calidad paisaje Tajo/Rajo Escombreras Dique de colas Planta de Proceso Directos Indirectos Indirectos 30 LEY NAC. N° 24.585 Fuente: Secretaría de Minería. 31 LEY 6.800 San Juan (modifica la ley 6.571) ARTICULO 4º.- El procedimiento de evaluación del Impacto Ambiental, con excepción del referido a la actividad minera, estará integrado por las siguientes etapas: 1- Manifestación del Impacto Ambiental 2- Audiencia Pública de los interesados o afectados. 3- Dictamen Técnico. 4- Declaración de Impacto Ambiental En el caso de la actividad minera, el procedimiento de evaluación será el dispuesto en el Código de Minería, Título Complementario de la Protección Ambiental para la actividad Minera, y reglamentación pertinente. COMISIÓN INTERDISCIPLINARIA DE EVALUACIÓN AMBIENTAL MINERA: evaluación de IIA: PASCUA-LAMA Decreto 1815/04 Consulta Pública (60 días) 32 Conflictos socioambientales en torno a la actividad minera metalífera. “MEGAMINERÍA” resultante del desacuerdo respecto al signo + o - de los impactos producidos por un proyecto minero. Confrontación u oposición entre los actores involucrados (Robledo & Lumerman 2009). Percepción social: intenta formar una impresión global de las otras personas u objetos. Muy resistentes al cambio, aún frente a información posterior contraria (Baron & Byrne 1994). 33 Degradation factors 1- Oil exploitation 2- Cattle raising Zuleta et al. 2012; Castro et al. 2012 34 Degradation characteristics Attribute Cattle Raising Mining regional local – (regional) Frequency permanent single events Life span permanent < 30-40 years Intensity low-selective severe, maximum Spatial scale Social perception + positive - negative 35 Vegetation, mounds and soil removal (local scale) 36 Landscape fragmentation (regional scale) Zuleta et al. (2011) 37 Overgrazing: ecological impact 58 56 54 Poa lanuginosa 9,667 52 cobertura promedio Cobertura de Poa lanuginosa 50 48 46 44 42 40 38 36 0,003 34 0 20 37 60 80 96 120 140 160 180 32 200 30 Ganadería (carga/km) inadecuado Mean ±SE ±1,96*SE adecuado manejo ganadero 23,077 Larrea divaricata 13,580 11,190 2,170 Baccharis spp 8,640 Baccharis sp. 1,830 3,803 1,500 0 20 37 60 80 96 120 140 160 180 200 Ganadería (carga/km) 1,530 Cobertura de Cobertura de Larrea divaricata 19,710 Loss of biodiversity Cover reduction (selective herbivory) Inadequate range management 0,477 0,237 20 Sade & Zuleta 2005 37 60 80 96 120 Ganadería (carga/km) 140 160 180 38 200 Degradation history: thresholds natural shrublands ↑ bare soil ↓ productivity ↓ cover of grasses active restoration Biotic threshold degraded ecosystems passive restoration Abiotic threshold bare soil 1890 grazing pressure starts XX Century 1960 XXI Century Legal Oil exploitation in our requirements study area Time 39 Natural dynamics 40 Why to study regeneration? Basic questions: 1st step in Ecological Restoration How degraded ecosystems respond to human activitities? Which are the reversibility thresholds? What trajectories prevail? Which are the key/critical species and processes? In summary, which are the driving factors? 41 The mound cycle Estimated mean time: 100‐200 years ... … depends on species & geomorphic processes. Low resilience and high resistence. Incidence of functional groups. Soriano et al. 1994 42 Mound estabilization Fertility islands High rates of sand accumulation Climax, late successional species establishment Microphytic crust formation Higher microbial activity 43 Predictive models, drivers Classic Clemensian model. State and transitions: thresholds. Regeneration in Monte Austral depends on: (1) disturbance intensity, (2) climate regime, and/or (3) geomorphological processes. 44 Clemensian model Begon et al. 2001 45 State & transitions: thresholds Hobbs & Harris 2001 Briske et al. 2006 46 Post-disturbance dynamics 1: soil recovery > 5-25 years 47 Soil indicators pH (NS) Dif. in % OM = -1.337 + 0.01783 * Time r = 0.35469 p=NS 0.6 1.0 0.6 10 years later 0.2 -0.2 -0.6 Difference in % Organic Matter 0.2 1.4 Difference in pH organic matter (NS) c Difference in pH = -0.2219 - 0.0002 * Time r = -0.0038 p=NS a 40-years chronosequence -1.0 -0.2 -0.6 -1.0 -1.4 -1.8 -2.2 -2.6 -1.4 -1.8 5 10 15 20 25 30 35 40 Time 0 5 10 15 20 25 30 35 40 45 Time 22 years later Gravel (P < 0.001) sand accumulation e Difference in % Gravel = 53.869 - 1.021 * Time r = -0.6998 p<0.001 d Difference in %Sand = -8.633 + 0.16852 * Time r = 0.48087 p<0.10 70 60 2 35-40 years later -2 -6 -10 Difference in % Gravel 6 Difference in % Sand 0 50 40 30 20 10 0 -10 -14 0 5 10 15 20 25 30 35 40 Time -18 0 5 10 15 20 Time 25 30 35 40 45 Fuchs et al. 2005 48 45 45 Ants: engineering spp Herbivorous ants: + effects, recolonization. 120 100 80 60 40 20 0 -20 Granivorous 100 % Granivorous nests % Herbivorous nests a y=28.191+0.304*x+eps b y=-4.156+1.2*x+eps 0 5 10 15 20 25 30 35 40 80 60 40 20 0 0 45 5 10 Dominant species Acromyrmex lobicornis Granivorous (seed harvester ants) Pogonomyrmex carbonarius Pheidole aberrans Omnivorous (including predators & liquid-feeders) Forelius chalibaeus Pheidole bergi % Omnivorus nests c Herbivorous (leaf-cutting ants) 20 25 30 35 40 45 Time since abandonment Time since abandonment Functional group 15 y=75.965-1.503*x+eps 120 Omnivorous 100 80 60 40 20 0 -20 0 5 10 15 20 25 30 35 40 Time since abandonment Gainza et al. 2005 49 45 Plant responses & restoration effectiveness Stage I: 0-2 years postscarification Scarification Technique: ecological similarity and successional stages (189 sites) I II Índice de Similitud de Sörensen 0.5 III pioneer spp ruderal spp 0.4 Stage II: 2-6 years 0.3 Stage III: 6-12…20-25? yr pioneer + climax spp 0.2 0.1 0.0 0 1 2 3 4 5 6 7 8 TDE (años) 9 10 11 12 13 14 Castro et al. 2011, 2012 50 Ecogeomorphologic model-1 State I pioneer species II I Abiotic Threshold (soil) bare soil 0 ruderal species 10 pioneer species I 20 Establishment of early successional species Soil / microsites recovery ↓ plant density ↓ plant morphology 30 40 50 60 Years Time since disturbance Sq: similarity Sorensen quantitative index 51 Sq Post-disturbance dynamics 2: plant facilitation 10-30 years 52 Vegetation regeneration 40-years chronosequence ¿which is the desire time or succesional stage? modelo de regresión lineal (R2 = 0,874; p< 0,001) nivel aceptable de similitud 10 years later 35 years later Reichman (2003) 53 Ecological Indicators Zuleta et al. 2003; Castro et al. 2011, 2012 54 Ecogeomorphologic model-2 I Biotic Threshold (plants) plant density plant morphology State II State III Establishment of late successional species State I pioneer species II I Abiotic Threshold (soil) bare soil 0 ruderal species 10 pioneer species I 20 Establishment of early successional species Soil / microsites recovery ↓ plant density ↓ plant morphology 30 40 50 60 Years Time since disturbance Sq: similarity Sorensen quantitative index 55 Sq Post-disturbance dynamics 3: mounds estabilization > 35-40 years 56 Mounds: all types 40-years chronosequence Types: m1: growth m2: stable m3: deflation Reichman (2003) 57 Mound restoration effectiveness Discriminant analysis - physical attributes (189 sites) degraded sites 8 years after scarification natural/reference site Ciancio et al. 2011, 2012 58 Sand offer & geomorphic unit Oferta de arena total (%) 90 C 75 B B 60 AB A 45 30 15 0 4 6 3 1 2 Macrounidad geomorfologica Ciancio et al. 2011, 2012 59 Ecogeomorphologic model-3 stable mounds sand accumulation II Abiotic Threshold (microtopography) I Biotic Threshold (plants) plant density plant morphology State II State III Establishment of late successional species State I pioneer species II I Abiotic Threshold (soil) bare soil 0 ruderal species 10 pioneer species I 20 Establishment of early successional species Soil / microsites recovery ↓ plant density ↓ plant morphology 30 40 50 60 Years Time since disturbance Sq: similarity Sorensen quantitative index 60 Sq Post-disturbance dynamics 4: wildlife permanent use > 50 years 61 Habitat wildlife recovery mostly burrowing species Fernández (2002) 62 Ecogeomorphologic model-4 Burrowing species II Biotic Threshold (habitat for wildlife) stable mounds sand accumulation II Abiotic Threshold (microtopography) I Biotic Threshold (plants) resident home-range plant density plant morphology State II State III Establishment of late successional species State I pioneer species II I Abiotic Threshold (soil) bare soil 0 ruderal species 10 pioneer species I 20 Establishment of early successional species Soil / microsites recovery ↓ plant density ↓ plant morphology 30 40 50 60 Years Time since disturbance Sq: similarity Sorensen quantitative index 63 Sq Restored dynamics - which are the desire stages? - when to rehabilitate? - how: low or high tech? 64 Restoration definitions Regeneration: natural process to return to an estable state after disturbance (natural or human). Ecosystem (active) restoration: deliberated intervention to repair the structure and/or function of an ecosystem that has been impacted by human disturbance (degraded, damaged, impacted). Passive restoration: = regeneration? 65 Tested techniques in NW Patagonia Antiherbivore protection Organic matter addition (Li Puma 2005) (Pérez et al. 2011) Planting & hidrogel (B. Leiva et al. 1990, Pérez et al. 2010) Decompactation & planting Branching (Zuleta et al. 2003) (Apcarian et al. 2002, Dalmasso 2010) 66 Mounding: 3-factors experiments Control Dense rectangule Dense circle 17 months after Li Puma et al. 2004 Low density circle 67 Ecogeomorphologic model Burrowing species II Biotic Threshold (habitat for wildlife) Low‐tech techniques plant density plant morphology 0 State II State III Establishment of late successional species State I pioneer species II I Abiotic Threshold (soil) bare soil resident home-range stable mounds sand accumulation II Abiotic Threshold (microtopography) I Biotic Threshold (plants) Sq ruderal species 10 pioneer species I 20 Establishment of early successional species Soil / microsites recovery ↓ plant density ↓ plant morphology 30 40 50 60 Years Time since disturbance Sq: similarity Sorensen quantitative index 68 Ecogeomorphologic model resident home-range Burrowing species II Biotic Threshold Sq stable mounds sand accumulation Low‐tech techniques Low‐tech techniques II Abiotic Threshold State II State III Establishment of late successional species I Biotic Threshold (plants) State I I Abiotic Threshold (soil) pioneer species II Establishment of early successional species Soil / microsites recovery pioneer species I bare soil 0 10 20 30 40 50 60 Years Time since disturbance Sq: similarity Sorensen quantitative index 69 Ecogeomorphologic model Burrowing species II Biotic Threshold Low‐tech techniques Low‐tech techniques resident home-range stable mounds II Abiotic Threshold sand accumulation State II State III Establishment of late successional species I Biotic Threshold I Abiotic Threshold (soil) Sq State I pioneer species II Establishment of early successional species Soil / microsites recovery pioneer species I bare soil 0 10 20 30 40 50 60 Years Time since disturbance Sq: similarity Sorensen quantitative index 70 Conclusions, future actions NW Patagonia shrublands regeneration: 40 years. Soil-plants-mounds dynamics is better explained by classic models (Clemensian, geomorphic). Mound re-establishment is the key component, whereas … sand accumulation is the key process. Low-tech restoration is a preferred option. 10-15 years: desired/feasible rehabilitation time. 2013: researching while restoring … or … restore under scientific designs, local-regional scales. 71 Gracias! … … grupo de investigación y fuentes de financiación 72