A survey was conducted among teak and melina growers across Costa Rica to assess their perceptions of problematic weed species and to document current weed management practices in forest plantations. A total of 180 farmers were selected from six provinces, yielding an 87% response rate. Results revealed that 47% of respondents had established plantations on formerly forested land, while 43% did so on previously used pastureland. Most farmers employed an integrated approach toward weed management that included manual, mechanical, and chemical methods. The most problematic species cited most frequently included coyol palm, jaraguagrass, orchid vine, raspa guacal, and arrocillo. Herbicide use was widespread, with glyphosate, metsulfuron-methyl, and paraquat being the most common active ingredients, typically applied singly, in mixtures, or sequentially. The findings reveal a heavy reliance on only three herbicides and highlight the need for targeted control of species in the Poaceae family and climbing vines. This work contributes valuable insights into weed dynamics in tropical forest plantations and emphasizes the need for region-specific and sustainable management strategies to mitigate potential productivity constraints and reduce reliance on herbicides.

Regional offsets from Northern Hemisphere radiocarbon (14C) calibration curves are widely recognized for monsoon Asia and often hinder accurate 14C dating. In this paper, we explore the possible linkage between summer monsoon intensity and 14C offsets using tree-ring δ18O and 14C data from Thailand. We developed a 297-yr floating tree-ring δ18O chronology comprising seven teak log-coffin samples from the Ban Rai rock shelter site, northwestern Thailand. The outermost ring of our chronology was estimated to date from 358–383 CE, within a 95.4% (2σ) probability range, based on a total of 10 14C measurements that were wiggle-matched against a mixed calibration curve evenly weighted from the IntCal20 and SHCal20 curves. Backward trajectory analysis showed that an intensified (weakened) summer monsoon detected in a modern tree-ring δ18O chronology was most likely to be induced by increased (decreased) air mass transport from the tropical Indian Ocean, which is an area of intense upwelling where the 14C concentration is lower than the atmospheric 14C level. However, partly because of the limited sample size and dating uncertainty, the direct linkage between the tree-ring δ18O series and 14C records obtained from our teak log-coffin samples could not be statistically verified.

We conducted an interview-based survey for the Javan warty pig Sus verrucosus, endemic to the islands of Java and Bawean in Indonesia. The species occurs in 10 isolated areas, although some additional, probably very small populations, may remain. Compared to a survey conducted in 1982, 17 of the 32 (53%) populations are extinct or have dropped to levels so low that local hunters have failed to encounter the species in recent years. This indicates a rapid population decline. We hypothesize that this loss is primarily caused by a decline in suitable habitat, especially stands of teak Tectona grandis forest or similar forest plantations, and by high hunting pressure. Competition from and hybridization with the Eurasian wild boar Sus scrofa may be further threats to S. verrucosus. Rapid action is needed to prevent extinction in the wild. We recommend effective protection of selected S. verrucosus populations, lobbying of the Government to give protected status to S. verrucosus, conducting ecological research and investigating crop damage issues, and establishment of conservation breeding programmes.