Seasonal changes in soil arthropod abundance in the dry evergreen forest of north‐east Thailand, with special reference to collembolan communities

Abstract

A soil arthropod community was studied in a dry evergreen forest over a 3-year period from May 1998 to April 2001. Population abundance, species composition, and community structure were investigated over the 3-year study period. The soil arthropods consisted of Acari (75.38%), Collembola (16.11%), and others (8.51%), and their abundances showed a clear difference between the rainy and dry seasons. Population abundance of Collembola and Acari were low during drought conditions. The humidity was the most important factor determining distribution, abundance, and survival of soil Collembola in this tropical forest. High predation and low accumulation of organic matter caused low population abundance of Collembola in the tropical habitat. The collembolan community was dominated by a few dominant species over the study period. The pattern of seasonal changes in numbers of Collembola was similar over the 3-year study period. The species composition of the collembolan community was constant and persistent throughout a 3-year study period. Thus, the collembolan community showed constancy in its species composition with seasonal variability over the 3-year study period.

Litter manipulation and the soil arthropod community in a lowland tropical rainforest

“…Relative proportions of taxa identified in this investigation were compared with those obtained by previous tropical studies (Buskirk and Buskirk, 1976;Leakey and Proctor, 1987;Atkin and Proctor, 1988;Paoletti et al, 1991;Wiwatwitaya and Takeda, 2004;Palacios-Vargas et al, 2007;De Morais et al, 2010) using NMDS based on BrayeCurtis dissimilarity.…”

“…Sub-samples for analysis of inorganic nitrogen were extracted in the field by immediately placing w10 g of soil in pre-weighed bottles containing 50 ml of 2 M KCl to minimise changes in nitrogen concentrations due to storage (Worsfold et al, 2005;Turner and Romero, 2009). Samples were centrifuged upon returning to the laboratory (<6 h) and the extracts were frozen prior to analysis for nitrate and ammonium by automated colourimetry using a Lachat Quikchem-8500 (Hach Ltd, Loveland, CO).…”

Efecto de plantaciones de pino en la artropofauna del suelo de un bosque Altoandino

“…Pese a ser mucho menor a lo reportado para diversos ecosistemas palearticos (Deharveng 1996, Fukuyama et al 1999, Wiwatwitaya & Takeda 2005, la densidad de artrópodos en el bosque altoandino fue cercana a la que se presenta en zonas inundables de la amazonía Peruana (Tapia-Coral et al 2002) y a las selvas tropicales en México (Prieto et al 1999) y Costa Rica (Heneghan et al 1999). Sin importar el sitio, la abundancia y riqueza en superficie superaron ampliamente a los horizontes orgánico y mineral.…”

“…En el bosque nativo dominó el grupo Collembola, con una representatividad del 42.4% y una abundancia similar a la de otros ecosistemas de bosque natural (Franklin et al 2001, Wiwatwitaya & Takeda 2005, mientras que la plantación de pino estuvo dominada por el grupo Acari con un 34% (Fig. 2).…”

“…En la superficie y el horizonte orgánico, el bosque altoandino mostró picos importantes de abundancia y riqueza que tienden a coincidir con los meses de febrero (primeras lluvias de año) y mayo (pico de precipitación anual); la respuesta al clima es similar a la reportada por Wiwatwitaya & Takeda (2005), quienes argumentan que las especies dominantes tienen sus picos de abundancia en las temporadas húme-das. La estacionalidad en el bosque altoandino estaría también marcada por una precipitación media (alrededor de 1 000mm) mucho menor a la que se da en otros bosques tropicales siempreverdes (superior a 3 000mm), donde la presencia de lluvias en medio del verano conlleva a un bajo contraste estacional y a una escasa variación de la biodiversidad del suelo en relación con el clima (Anu et al 2009).…”