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.

Predation and Risk Behaviors of Free-Roaming Owned Cats in Auckland, New Zealand via the Use of Animal-Borne Cameras

“…Other possible explanations for the absence of mammalian and avian prey include individual cat prey preferences and a short data collection period which did not cover multiple seasons. It is possible that the seasons in which data were collected may affect prey abundance and availability (44–47). In addition, it has been suggested that an infrared LED, such as that next to the KittyCam © camera lens, which allowed for recording in darkness, may influence the behavior of potential prey (37, 48).…”

“…Underestimation of invertebrate capture may be especially common, with 31 invertebrates being captured and/or killed in-situ in the current study, 12 of which were native species. The capture data in this study were collected largely during warmer months when the abundance of some prey species, including invertebrates, has been found to be highest (44, 47). This in turn may have produced results that overestimate invertebrate predation, if extrapolated throughout the rest of the year.…”

Influence of winter weather conditions on lesser short‐tailed bat(Mystacina tuberculata)activity inNothofagusforest, Fiordland

“…Food availability and climate are the two likely interacting factors which influence whether lesser short-tailed bats are active over winter. Podocarp forests are generally more diverse, have higher productivity and therefore more food than beech forests (Moeed & Meads 1984, 1985, 1987O'Donnell &Dilks 1994).…”

Responses of litter‐dwelling arthropods and house mice to beech seeding in the Orongorongo Valley, New Zealand

“…From January 1992, arthropods of the litter were sampled in hard beech and silver beech forest The study also continued the long-term measurements of hard beech seeding, mice, and moths emerging from the forest floor (Fitzgerald et al 1996) From January 1994, when Landcare Research shifted its Hutt Valley campus to Palmerston North, new staff carried out all field and laboratory work, and considerable effort was made to continue sampling in exactly the same way This was not entirely successful (see below) Species were identified by the same people throughout the study Arthropod sampling general comments Arthropods were sampled by three methods used previously in the Orongorongo Valley by Moeed & Meads emergence traps (Moeed & Meads 1987b), pitfall traps (Moeed & Meads 1985), and Tullgren extraction (Moeed & Meads 1986, 1987a Emergence traps had been operated in hard beech forest each summer from 1985/86 to 1990/91 to measure the emergence of moths from the litter (Fitzgerald et al 1996) From November 1991 they were operated continuously until May 1996 From January 1992 arthropods were also sampled in hard beech and silver beech forest by pitfall trapping and Tullgren extraction of litter Pitfall traps mainly catch animals that move on the forest floor, and the Tullgren method extracts animals that live within the litter In sampling arthropods by emergence traps and Tullgren samples, areas of the forest floor with uniform litter were selected so that results could be strictly comparable throughout the study. Areas with litter-catching plants, such as Blechnum discolor, and mosses, liverworts, or filmy ferns, were avoided, and litter adjacent to logs was not sampled.…”

“…The invertebrates of some forest habitats in the Orongorongo Valley were surveyed by A Moeed and M J Meads in the 1970s, using various methods (those relevant to the present study were Moeed & Meads 1985, 1986, 1987a, 1987b The litter-feeding Lepidoptera larvae are described by Dugdale (1996) The beetles in our samples of hard beech litter in late spring and summer, 1992-95, were reported by Khmaszewski & Kuschel (1996) House mice are present throughout the forest and ship rats (Rattus rattus) mainly in podocarp/ hardwood forest Feral cats (Fehs catus), stoats, and a few weasels {Mustela nivahs) are present The stoats, unlike those in beech forests of the South Island, usually do not increase in numbers after beech seeding (Fitzgerald & Karl 1979, Gibb & Fitzgerald 1998 Physical and climatic features of the floor of hard beech and silver beech forests were described by Moeed & Meads (1985, 1986 Litter on the forest floor comprises three mtergradmg layers The uppermost litter, or L layer, consists of recently fallen litter (leaves, flowers, pollen, twigs, branches, exfoliated bark) This rests on and grades into a zone of decaying, fungi-, yeast-, and bacteria-ridden material, the fermentation or F layer, which in turn grades into the finely comminuted humus, with roots and mycorrhizae, of the humus or H layer, resting on the mineral soil Lepidoptera larvae exploit the L and F layers, and also the litter accumulated above ground in tussocks of Microlaena avenacea, rosettes of ferns such as Blechnum discolor, and the scrambling kiekie Freycinetia baueriana (Dugdale 1996) Beech leaves fall throughout the year, but most hard beech leaves fall in October to December and silver beech leaves in January and April-May Hard beech sheds its spent male flowers mainly in October and seeds in March April, silver beech sheds male flowers later, in November December, and seeds in April (Alley et al 1998) …”