Seasonality and density of litter and humus invertebrates in broadleaf-podocarp and hard beech forests in Orongorongo Valley, New Zealand

Abstract

Invertebrates were studied with equal sampling intensity on sites in broadleaf-podocarp and hard beech (Nothofagus truncata) forests near Wellington, New Zealand for 13 months. Of the 107 species caught (72 500 individuals), 71 (41 931) occurred in broadleaf-podocarp and 78 (30 569) in hard beech forest. Mites (75.3% of individuals), Collembola (9.6%), insect larvae (4.9%), and beetles and weevils (3.6%) were most common. In broadleaf forest numbers were higher in summer than in other seasons and in hard beech forest numbers were higher in spring than in other seasons. The seasonal changes in numbers of many invertebrate species were correlated with temperature but only few with rainfall. Invertebrate diversity was similar in the two forests studied, but the density was greater in broadleaf than in hard beech.

Keywords:

• Invertebrates
• litter fauna
• humus fauna
• seasonality
• forest communities
• broadleaf-podocarp
• Nothofagus truncata
• Orongorongo Valley