Integrating fine-scale topography and stand structure to explain herb-layer diversity in forest ecosystems

Authors

• CARLA-MARIA APARASCHIVE, Department of Forestry, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, RomaniaFollow
• PAUL SESTRAS, Department of Land Measurements and Exact SciencesUniversity of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, Romania ; Academy of Romanian Scientists, Bucharest, RomaniaFollow
• ALINA M. TRUTA, Department of Forestry, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, RomaniaFollow
• IRINA M. MORAR, Department of Forestry, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, Romania 3Academy of Romanian Scientists, Bucharest, RomaniaFollow
• CATALINA DAN, Department of Horticulture and Landscape, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, RomaniaFollow
• MONICA BOSCAIU, Mediterranean Agroforestry Institute, Polytechnic University of Valencia, Valencia, SpainFollow
• FLORIN IORAS, Department of Research and Enterprise, Buckinghamshire New University, High Wycombe, United KingdomFollow
• ADRIANA F. SESTRAS, Department of Forestry, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Cluj-Napoca, RomaniaFollow

Abstract

Herb-layer diversity in temperate forests emerges from the interaction between stand structure and fine-scale environmental variation. We studied eight mixed beech–hornbeam and oak–hornbeam plots distributed along a short altitudinal gradient (170–310 m) and contrasting slope aspects in East Europe. For each plot, we measured tree diameter, height and crown-base height, and derived stand structural indices (tree density, basal area, Gini coefficients for DBH diameter at breast height and total height, and median crown base height). Herb-layer communities were characterized using standard diversity indices and Ellenberg indicator values. We then used Jaccard similarity to explore tree–herb cooccurrence and Spearman correlations to relate stand structure to herb-layer diversity. Stands differed markedly in structure along the combined elevation–aspect gradient. Basal area peaked at middle elevation on the north-facing slope and at high elevation on the south-facing slope, whereas size inequality and crown-base height showed contrasting patterns among plots, reflecting a mosaic of dense, structurally heterogeneous stands and more open, even-sized canopies. Herb-layer richness and evenness increased with higher median crown-base height and lower size inequality, but declined with increasing basal area and stem density. Ellenberg values confirmed that open mixed stands supported more light-demanding herbs, while dense, beech-dominated stands were characterized by a few shade specialists. Tree–herb cooccurrence patterns were generally weak, indicating mostly generalist herbs with a few consistent associations. Overall, our results show that simple stand structural indices, combined with fine-scale topography, can effectively predict herb-layer diversity and provide useful indicators for biodiversity-oriented forest management.

Author ORCID Identifier

CARLA-MARIA APARASCHIVE: 0009-0008-4040-4989

PAUL SESTRAS: 0000-0002-8554-0924

ALINA TRUTA: 0000-0002-3126-9761

IRINA MORAR: 0000-0002-8441-3667

CATALINA DAN: 0000-0002-3545-602X

MONICA BOSCAIU: 0000-0002-9691-4223

FLORIN IORAS: 0000-0002-7697-3381

ADRIANA SESTRAS: 0000-0001-5768-4296

DOI

10.55730/1300-011X.3496

Keywords

Altitudinal gradient, slope aspect, ground vegetation, beech, microsite, indicator plant species

First Page

680

Last Page

698

Publisher

The Scientific and Technological Research Council of Türkiye (TÜBİTAK)

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

APARASCHIVE, C, SESTRAS, P, TRUTA, A. M, MORAR, I. M, DAN, C, BOSCAIU, M, IORAS, F, & SESTRAS, A. F (2026). Integrating fine-scale topography and stand structure to explain herb-layer diversity in forest ecosystems. Turkish Journal of Agriculture and Forestry 50 (5): 680-698. https://doi.org/10.55730/1300-011X.3496