Landscape scale effects of primary productivity on forest bird species occurrence and abundance in Argentina

Download Olah et al_2025_Argentina_DHIs_scalograms_bird occurence_abundance

Context Approaches estimating landscape effects
on biodiversity frequently focus on a single extent,
finding one ‘optimal’ extent, or use narrow extents.
However, species perceive the environment in different
ways, select habitat hierarchically, and respond to
multiple selection pressures at extents that best predict
each pressure.
Objective We aimed to assess multi-scale relationships
between primary productivity and species
occurrences and abundances.
Methods We used a multi-scale approach, called
‘scalograms’, to assess landscape level effects of primary
productivity, in the form of Dynamic Habitat
Indices (DHIs) on the occurrences and abundances of
100 Argentinian forest bird species. We used average
DHI values within multiple extents (3 × 3 to 101 ×
101 pixels; 30 m resolution), and 11 ‘scalogram’ metrics
as environmental inputs in occurrence and abundance
models.
Results Average cumulative DHI values in extents
81 × 81 to 101 × 101 pixels (5.9 – 9.2 km2)
and maximum
cumulative DHI across extents were in the top
three predictors of species occurrences (included in
models for 41% and 18% of species, respectively).
Average cumulative DHI values in various extents
contributed ~ 1.6 times more predictive power to
occurrence models than expected. For species abundances,
average DHI values and scalogram measures
were in the top three predictors for < 2% of species and contributed less model predictive power than expected, regardless of DHI type (cumulative, minimum, variation). Conclusions Argentinian forest bird occurrences, but not abundances, respond to high levels of primary productivity at multiple, broad extents rather than a single ‘optimal’ extent. Factors other than primary productivity appear to be more important for predicting abundance.