{'fraction_non_alphanumeric': 0.03841536614645858, 'fraction_numerical': 0.025210084033613446, 'mean_word_length': 5.2434456928838955, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Diversity, distributions and conservation biogeography

Diversity and Distributions (DDI) was launched in January 1998. In its seven years of existence, the journal has published numerous outstanding papers dealing with many facets of the ecology of biodiversity. All the topics suggested as key themes for the journal in my editorial in the inaugural issue (Richardson, 1998) have attracted contributions. As promised, biological invasions have been given prominence in the journal. In the past decade invasion ecology has emerged as a crucial area of study for ecologists worldwide. There are several reasons for this. Firstly, there is an urgent need to gain a predictive understanding of invasions to reduce the impacts of current invaders and prevent further invasions. Secondly, ecologists and biogeographers are increasingly seizing opportunities provided by human-mediated introductions of organisms for unravelling crucial elements of the ecology of diversity and distributions. Papers focussing on aspects of introduced species have appeared in most of the 37 issues (including three double issues) of DDI. Contributions on this theme have ranged from detailed studies of single invasive species (e.g. Jakobs et al., 2004), thorough studies of the invasive biota in particular regions (e.g. Dark, 2004), assessments of mechanisms whereby alien species impact on invaded systems (e.g.Rossiter et al., 2003), detailed modelling studies (e.g. Welk et al., 2002), to conceptual contributions (e.g. Colautti & MacIsaac, 2004;Huston, 2004). A highlight was the double thematic issue on ‘Plant Invasion Ecology’ that appeared in September 2004 (Richardson, 2004).