An insight into the patterns and controls of the structure of South America n Chaco woodlands

FERRAINA, ANTONELLA; BALDI, GERMÁN; DE ABELLEYRA, DIEGO; GROSFELD, JAVIER; VERÓN, SANTIAGO R.

LAND DEGRADATION & DEVELOPMENT

JOHN WILEY & SONS LTD

Lugar: Londres; Año: 2022 p. 1 - 16

1085-3278

Logging, grazing, wood extraction, and anthropogenic fires are pervasive throughoutthe subtropical dry vegetation of South America leading to changes in woodlandsstructure and ultimately its degradation. The Chac ohaco biome encompasses thesecond-largest forest in South America and has a long history of intensive use. Wesought to characterize the structure and heterogeneity of its woodlands across biogeographicsubunits and climatic gradients, and evaluate structure controls. We quantifiedcanopy height, cover, vertical complexity, vegetation amount above 3 m and total vegetationamount over 58 woodlands within the Argentinean Chaco by means of terrestriallaser scanner. We assessed the relationship between three groups near themaximum, average and minimum values of each structural variable and precipitation,temperature and temperature of the coldest month using quantile regressions. Wefound large variability in structural attributes within each biogeographical subunit,showing woodland areas with similar structure across broad gradients of climate. Thissuggests a considerable impact of current and past land use in shaping woodland structuresacross the Chaco. Overall, structural variables were positively associated withprecipitation and temperature, albeit more strongly to the former, except for canopyheight, which showed a strong association with mean temperature of the coldestmonth. We hypothesize that land-use impact on woodland structure decreases withincreasing precipitation, as the lack of water may limit the recovery of vegetation structure.Our results contribute to a better understanding of variation in key structural variablesof Chaco woodlands in relation to climate and land use.