Daniel Curdie

The number of naturalised and invasive woody plant species has increased rapidly in recent decades. Despite the increasing interest in tree and shrub invasions, little is known about the invasion ecology of most species. This paper explores the global movement of species in the genus Melaleuca (Myrtaceae; here including the genus Callistemon). We assess the global introduction history, distribution and biogeographic status of the genus. Various global species occurrence databases, citizen science (iNaturalist), and the literature were used.Seventy-two species [out of 386 Melaleuca species; 19%] have been introduced to at least 125 regions outside their native range. The main regions of global Melaleuca introductions are Southeast Asia, the southern parts of North America, south-eastern South America, southern Africa and Europe. The earliest record of a Melaleuca species outside of the native range of the genus is 1789. First records of Melaleuca species outside their native range were most commonly recorded in the 1960s, with records from all over the world. The main reasons for Melaleuca introductions were for use in the tea tree (pharmaceutical value) and ornamental horticulture industries. Melaleuca introductions, naturalizations and invasions are recent compared to many other woody plant taxa. Experiences in Florida and South Africa highlight the potential of Melaleuca species to spread rapidly and have significant ecological impacts. It is likely that the accumulating invasion debt will result in further naturalization and invasion of Melaleuca species in the future.

Fossils from tropical Asia, which are far from fully investigated, are important for understanding the evolution of plant diversity and the associated surrounding environment there. In this study, we report, as the first record in Thailand, the well-preserved leaf fossils of Calophyllum Linnaeus (Calophyllaceae) from the upper Oligocene–Lower Miocene lacustrine deposits in Li Basin, northern Thailand. The fossils were identified through detailed comparison with leaves of extant and fossil species. These leaf fossils are assigned to Calophyllum based on several key leaf characteristics such as oblanceolate or oblong in shape and parallel secondary veins, nearly perpendicular to the midvein, as well as secondary veins alternate, closely placed, craspedodromous, parallel, dense, and distinct on surface, forming marginal veins. Based on detailed morphological comparison, these fossil leaves are assigned to C. suraikholaensis Awasthi and Prasad, 1990 and Calophyllum sp. The discovery of Calophyllum indicates a montane subtropical to tropical climate in northern Thailand during the Oligocene–Miocene. Together with previous fossil records, these results suggest that this genus probably originated in India during the Paleogene, and spread from India to Indochina during the Neogene, leading to its modern distribution, which currently prefers tropical climates.

Predicting the likelihood that non-native species will be introduced into new areas remains one of conservation’s greatest challenges and, consequently, it is necessary to adopt adequate management measures to mitigate the effects of future biological invasions. At present, not much information is available on the areas in which non-native aquatic plant species could establish themselves in the Iberian Peninsula. Species distribution models were used to predict the potential invasion risk of (1) non-native aquatic plant species already established in the peninsula (32 species) and (2) those with the potential to invade the peninsula (40 species). The results revealed that the Iberian Peninsula contains a number of areas capable of hosting non-native aquatic plant species. Areas under anthropogenic pressure are at the greatest risk of invasion, and the variable most related to invasion risk is temperature. The results of this work were used to create the Invasion Risk Atlas for Alien Aquatic Plants in the Iberian Peninsula, a novel online resource that provides information about the potential distribution of non-native aquatic plant species. The atlas and this article are intended to serve as reference tools for the development of public policies, management regimes, and control strategies aimed at the prevention, mitigation, and eradication of non-native aquatic plant species.

The early Eocene (∼56‐48 million years ago) is characterised by high CO2 estimates (1200‐2500 ppmv) and elevated global temperatures (∼10 to 16°C higher than modern). However, the response of the hydrological cycle during the early Eocene is poorly constrained, especially in regions with sparse data coverage (e.g. Africa). Here we present a study of African hydroclimate during the early Eocene, as simulated by an ensemble of state‐of‐the‐art climate models in the Deep‐time Model Intercomparison Project (DeepMIP). A comparison between the DeepMIP pre‐industrial simulations and modern observations suggests that model biases are model‐ and geographically dependent, however these biases are reduced in the model ensemble mean. A comparison between the Eocene simulations and the pre‐industrial suggests that there is no obvious wetting or drying trend as the CO2 increases. The results suggest that changes to the land sea mask (relative to modern) in the models may be responsible for the simulated increases in precipitation to the north of Eocene Africa. There is an increase in precipitation over equatorial and West Africa and associated drying over northern Africa as CO2 rises. There are also important dynamical changes, with evidence that anticyclonic low‐level circulation is replaced by increased south‐westerly flow at high CO2 levels. Lastly, a model‐data comparison using newly‐compiled quantitative climate estimates from palaeobotanical proxy data suggests a marginally better fit with the reconstructions at lower levels of CO2.

During the early to middle Eocene, a mid‐to‐high latitudinal position and enhanced hydrological cycle in Australia would have contributed to a wetter and “greener” Australian continent where today arid to semi‐arid climates dominate. Here, we revisit 12 southern Australian plant megafossil sites from the early to middle Eocene to generate temperature, precipitation and seasonality paleoclimate estimates, net primary productivity (NPP) and vegetation type, based on paleobotanical proxies and compare to early Eocene global climate models. Temperature reconstructions are uniformly subtropical (mean annual, summer, and winter mean temperatures 19–21 °C, 25–27 °C and 14–16 °C, respectively), indicating that southern Australia was ∼5 °C warmer than today, despite a >20° poleward shift from its modern geographic location. Precipitation was less homogeneous than temperature, with mean annual precipitation of ∼60 cm over inland sites and >100 cm over coastal sites. Precipitation may have been seasonal with the driest month receiving 2–7× less than mean monthly precipitation. Proxy‐model comparison is favorable with an 1680 ppm CO2 concentration. However, individual proxy reconstructions can disagree with models as well as with each other. In particular, seasonality reconstructions have systemic offsets. NPP estimates were higher than modern, implying a more homogenously “green” southern Australia in the early to middle Eocene, when this part of Australia was at 48–64 °S, and larger carbon fluxes to and from the Australian biosphere. The most similar modern vegetation type is modern‐day eastern Australian subtropical forest, although distance from coast and latitude may have led to vegetation heterogeneity.

We present a composite terrestrial pollen record of latest Eocene through Oligocene (35.5–23 Ma) vegetation and climate change from the Gippsland Basin of south-eastern Australia. Climates were overwhelmingly mesothermic through this time period, with mean annual temperature (MAT) varying between 13 and 18 °C, with an average of 16 °C. We provide evidence to support a cooling trend through the Eocene–Oligocene Transition (EOT), but also identify three subsequent warming cycles through the Oligocene, leading to more seasonal climates at the termination of the Epoch. One of the warming episodes in the Early Oligocene appears to have also occurred at two other southern hemisphere sites at the Drake Passage as well as off eastern Tasmania, based on recent research. Similarities with sea surface temperature records from modern high southern latitudes which also record similar cycles of warming and cooling, are presented and discussed. Annual precipitation varied between 1200 and 1700 mm/yr, with an average of 1470 mm/yr through the sequence. Notwithstanding the extinction of Nothofagus sg. Brassospora from Australia and some now microthermic humid restricted Podocarpaceae conifer taxa, the rainforest vegetation of lowland south-eastern Australia is reconstructed to have been similar to present day Australian Evergreen Notophyll Vine Forests existing under the sub-tropical Köppen-Geiger climate class Cfa (humid subtropical) for most of the sequence. Short periods of cooler climates, such as occurred through the EOT when MAT was ~ 13 °C, may have supported vegetation similar to modern day Evergreen Microphyll Fern Forest. Of potentially greater significance, however, was a warm period in the Early to early Late Oligocene (32–26 Ma) when MAT was 17–18 °C, accompanied by small but important increases in Araucariaceae pollen. At this time, Araucarian Notophyll/Microphyll Vine Forest likely occurred regionally.

Aim: Due to the sessile nature of flowering plants, movements to new geographical areas occur mainly during seed dispersal. Frugivores tend to be efficient dispersers because animals move within the boundaries of their preferable niches, so seeds are more likely to be transported to environments tha…

The Qinghai-Tibetan Plateau (QTP) harbors abundant and diverse plant life owing to its high habitat heterogeneity. However, the distribution pattern of biodiversity hotspots and their conservation status remain unclear. Based on 148,283 high-resolution occurrence coordinates of 13,450 seed plants, w…

Evolvulus nummularius (L.) L., a member of the Convolvulaceae, is native to Mexico and South America but nowadays grows around the world in many tropical and subtropical regions. Its presence in Pakistan, where it has become naturalized, is reported here for the first time. It was first discovered i…

Carnivorous plants (CPs)—those possessing specific strategies to attract, capture and kill animal prey and obtain nutrition through the absorption of their biomass—are harbingers of anthropogenic degradation and destruction of ecosystems. CPs exhibit highly specialised and often very sensitive ecolo…