Environmental controls of NDVI dynamics in Patagonia based on NOAA‐AVHRR satellite data

Paruelo, José M.; Aguiar, Martı́n R.; Golluscio, Rodolfo A.; León, Rolando J.C.; Pujol, Gloria

doi:10.2307/3235602

Cited by 27 publications

(13 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The same relationship between precipitation and ANPP based on field data was derived using the integral of the NDVI as an estimate of ANPP . Paruelo et al (1993) for Patagonia, and Malo and Nicholson (1990) for the Sahel also reported a linear relationship between the NDVI integral and precipitation. Paruelo et al (1997) showed a strong correlation between the NDVI-I and ANPP for the Central Grassland region of the United States.…”

Section: Discussionmentioning

confidence: 99%

Functional and Structural Convergence of Temperate Grassland and Shrubland Ecosystems

Paruelo

Jobbágy

Sala

et al. 1998

Ecological Applications

Self Cite

142

View full text Add to dashboard Cite

We analyzed the similarity of structural and functional characteristics of temperate grassland and shrubland ecosystems of North and South America. We based our analyses on correlative models that describe the climatic controls of grassland and shrubland structure and functioning at regional scales. We evaluated models that describe the regional distribution of plant functional types (C3 and C4 grasses and shrubs), soil organic carbon (SOC), and aboveground net primary production (ANPP) and its seasonality. To evaluate the predictive power of the models, we compared their estimates against observed data. We derived data sets, independent from those used to generate the models in North America, from climatically similar areas in South America. Our results support the notion that, in climatically similar regions, structural and functional attributes such as plant functional type composition, SOC, ANPP, and ANPP seasonality have similar environmental controls, independent of the evolutionary history of the regions. The study suggests the existence of an important degree of convergence at regional scales in both functional and structural attributes. It also points out differences in the regional patterns of some attributes that require further analyses.

show abstract

Section: Discussionmentioning

confidence: 99%

Functional and Structural Convergence of Temperate Grassland and Shrubland Ecosystems

Paruelo

Jobbágy

Sala

et al. 1998

Ecological Applications

Self Cite

142

View full text Add to dashboard Cite

show abstract

“…Grazing has led to a reduction in plant cover (Paruelo et al, 1993;Sala, 1988), decreased abundance of palatable species (Aguiar and Sala, 1998;Cingolani et al, 2005;Defossé et al, 1990;Soriano, 1983) and losses in the size and diversity of soil seed banks (Bertiller, 1992(Bertiller, , 1998Ghermandi, 1997;Ghermandi and Gonzalez, 2008).…”

Section: Introductionmentioning

confidence: 99%

Studying the post-fire performance of tussock grasses in Patagonia: Survival, biomass production and early competition

Gittins¹,

Ghermandi²,

Bran³

2011

Journal of Arid Environments

View full text Add to dashboard Cite

“…Due to the apparent simplicity of their structure and physiology, grasslands have been the subject of many remote sensing studies aimed at understanding vegetation reflectance properties and their significance to plant and ecosystem processes (e.g., Sellers et al 1988, Burke et al 1991, Dyer et al 1991, Turner et al 1992, Paruelo et al 1993, Lauenroth and Paruelo 1995. However, management practices typical in most grasslands (such as burning and grazing) regulate nutrient cycling, ecosystem composition, and distribution of organic matter in ways that deviate from undisturbed systems (Dyer et al 1991, Hobbs et al 1991).…”

Section: Introductionmentioning

confidence: 99%

Detecting Fire and Grazing Patterns in Tallgrass Prairie Using Spectral Mixture Analysis

Wessman

Bateson

Benning

1997

Ecological Applications

View full text Add to dashboard Cite

Global grasslands are typically under management practices (such as fire and grazing) that alter nutrient cycling, ecosystem composition, and distribution of organic matter from the unmanaged condition. We evaluated landscape‐level response to fire and grazing treatments in the Konza Tallgrass Prairie Research Natural Area, Kansas, using spectral mixture analysis of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data acquired 31 August 1990. Spectral mixture analysis derives the fractional abundances of spectrally unique components in the landscape. The reflectance spectra of these components are called endmembers. Endmember fractions values were compared against ground values of live biomass, current standing dead biomass, and litter for 12 watersheds. Analysis of variance (ANOVA) was performed on 37 watersheds with known burning and grazing histories for each of the remote sensing variables. Seven endmembers were selected from the AVIRIS data using a manual endmember selection method: nonphotosynthetic vegetation (NPV), soil, rock, shade, and three green vegetation endmembers (GV1, GV2, and GV3). Each vegetation endmember correlated differently to biomass measurements and revealed unique relationships to management treatments. From regressions, ANOVAs, and image analysis, these three endmembers were inferred to represent canopy vertical structure or leaf area index (LAI), greenness, and fractional cover of grass, respectively. There was a stronger relationship between the sum of GV1 and GV3 fractions and live grass biomass values than there was with the (unsummed) individual fractions. In an ANOVA, the sum separated both burn and grazing treatments as well as the treatment interaction. The NPV fraction was strongly correlated with ground measurements of litter and standing dead biomass, and significantly separated burn treatments. The soil fraction differentiated grazing treatments, and analysis of the soil fraction image revealed a spatial coherence of grazing patterns along drainages. Similar analyses were perfomed on the Normalized Difference Vegetation Index (NDVI), a commonly used two‐band index computed from red and near‐infrared reflectance. NDVI, shown in previous studies to estimate the fraction of photosynthetically active radiation absorbed by green vegetation (FPAR), was a poor indicator of canopy biomass, but it successfully separated fire treatments. Broad‐scale assessment of the state and structure of managed grassland systems requires the identification of several indicator variables. Spectral mixture analysis, unlike NDVI, not only separated treatments but also allowed for the identification of five remotely sensible factors affected by the management treatments, namely, vertical structure, percentage cover or patchiness, greenness, and distribution of soil and litter.

show abstract

Environmental controls of NDVI dynamics in Patagonia based on NOAA‐AVHRR satellite data

Cited by 27 publications

References 18 publications

Functional and Structural Convergence of Temperate Grassland and Shrubland Ecosystems

Functional and Structural Convergence of Temperate Grassland and Shrubland Ecosystems

Studying the post-fire performance of tussock grasses in Patagonia: Survival, biomass production and early competition

Detecting Fire and Grazing Patterns in Tallgrass Prairie Using Spectral Mixture Analysis

Contact Info

Product

Resources

About