Ant-Gardens on the giant bamboo Gigantochloa scortechinii (Poaceae) in West-Malaysia

Abstract

We report the first experimental evidence of seed collecting behavior in an ant-garden-inhabiting ant species in the Palaeotropics.Vascular epiphytes growing on the giant bamboo Gigantochloa scortechinii (Poaceae) were collected at Ulu Gombak, West Malaysia. Sixteen epiphyte species were growing in carton-nests of seven ant species. All epiphytes on bamboo were associated with ants. The most frequent ant species (Crematogaster sp.1, Myrmicinae) apparently nests only on bamboo. It was tested for its behavior towards the seeds of three epiphyte species (Dischidia nummularia (Asclepiadaceae), Aeschynanthus fecundus, Aeschynanthus albidus (Gesneriaceae)) and one non-epiphyte species (Emilia sonchifolia (Asteraceae)). Most of the offered epiphytes' seeds were carried to the nest, while the seeds of the non-epiphyte were ignored or even discarded. There were no speciesspecific differences among the epiphytes' seeds.We hypothesize that seed-collecting behavior is necessary for the establishment of ant-garden associations and for the colonization of bamboo culms by epiphytes. The smoothsurfaced and relatively short-lived bamboo culms would not host epiphytes without the mediation of the ants. We suspect that ants may also have a great influence on the distribution of epiphytes on other hosts.In this paper we describe ants as active nest builders and seed collectors that give certain epiphytes the opportunity to live in open and sun exposed habitats on bamboo. Benefits to the ants are discussed as well.

Dischidia (Apocynaceae, Asclepiadoideae) in Laos and Vietnam

“…Our observations agree with both experimental and informal observations of other Dischidia species (Kaufmann et al, 2001 and references therein; Kleijn & Van Donkelaar, 2001). A phylogenetic analysis of Dischidia (Livshultz, 2003a) shows that the occurrence of ant-associations is widespread in the genus and not limited to any single clade.…”

“…A phylogenetic analysis of Dischidia (Livshultz, 2003a) shows that the occurrence of ant-associations is widespread in the genus and not limited to any single clade. Many species of Hoya, the sister genus of Dischidia, also form ant associations (Kaufmann et al, 2001 and references therein; Kleijn & Van Donkelaar, 2001). The wide distribution of ant-associations in Dischidia and Hoya suggests that this trait could be plesiomorphic in these epiphytes.…”

Ant-gardens of tropical Asian rainforests

“…During our studies on ant-plant associations in Malaysia, we discovered a common AG symbiosis (Kaufmann et al 2001). This was the basis for an extensive investigation on ant-epiphyte associations in Peninsular Malaysia and comparative studies in Sabah, Sarawak, southern Thailand, and central Java.…”

“…In contrast, reports on similar associations in the paleotropics are scarce so far. After discovering a first common AG system on giant bamboo [Kaufmann et al (2001) 48:125-133], we started a large-scale survey for AGs in Peninsular Malaysia, Borneo, Java, and southern Thailand. A great variety of AG systems (altogether including 18 ant species and 51 plant species) was discovered and is described in the present paper.…”

The Florida Harvester Ant, Pogonomyrmex badius, Relies on Germination to Consume Large Seeds

“…Despite the apparent strategies to prevent the germination of stored seeds by harvesters, many ant species share mutualistic relationships with plants and actively promote the germination of, and plant numerous myrmecophorous seed species [9,29,30,31]. Only anecdotal accounts of granivorous ants cohabitating with germinating seeds exist, and the relationship is decidedly predatory.…”