Changes in land cover resulting from the introduction of non‐native pine modifies litter traits of temperate forests in Patagonia

BLACKHALL, MELISA; FRANZESE, JORGELINA; RODRIGUEZ, JOHANNA; RAFFAELE, ESTELA; SOTO, ALEJANDRA Y.

JOURNAL OF VEGETATION SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020 vol. 31 p. 223 - 233

1100-9233

Aims: Changes in land cover resulting from the introduction of non-native pine plantationsand subsequent pine invasion is increasingly affecting forest areas in theSouthern Hemisphere, and having negative impacts on diverse ecosystem components.We studied the abundance, biophysical attributes, and flammability of litter intemperate forests modified by the introduction of the non-native Pinus radiata, andlater by its post-fire invasion from adjacent sites. We also evaluated the short-termeffects on litter of mechanical removal of P. radiata from post-fire invasion sites.Location: North-western Patagonia, Argentina.Methods: We measured abundance, depth, moisture content and determined speciescomposition of litter samples collected at native forest, plantation, and post-fire invasionand removal sites. We also performed flammability tests on leaf litter samples ofthe dominant species from each habitat type. In all cases, litter traits from the modifiedhabitats were compared with those obtained from native forest (reference system).Results: Moisture content and litter species composition were notably affected bythe alteration of habitat. A decrease in species richness and changes in the identityand abundance of the dominant species were the most remarkable shifts recorded inthe modified habitats. While pine needles were mainly associated with parametersindicative of high leaf litter flammability, the opposite was found for leaves of thedominant native trees. The removal of invasive pines from early post-fire invasion didnot reveal any biophysical changes in litter that would indicate a tendency towardsthe conditions found in native forest litter.Conclusions: Pine needles as a novel element in litter found in pine-dominated habitatshave a prominent impact on litter traits associated with alterations in key ecosystemproperties in comparison with the reference system. For a short-term recoveryof burned, invaded areas, additional ecological practices other than the removal ofinvasive trees should be conducted to successfully drive successional changes towardsconditions similar to those found in native vegetation.