Print PageConservation and management of species listed under the Endangered Species Act should be informed by the best available science. Ideally research reflects risks to species and provides insight into ways to reduce such risk. Unfortunately, the disciplinary expertise of people setting priorities often strongly results in less than objective research and management priorities. One long-standing debate is the relative risk from genetic versus ecological or demographic factors, which is often confounded with the relative utility of genetic data. Some suggest genetics contribute relatively little to risk and consider genetic data superfluous. In reality, genetic and demographic risks ensue simultaneously as species decline. Yet not all who consider genetic risks to be important consider genetic data informative; others consider them superior to alternatives. Appeals for integrated conservation strategies that incorporate multiple types of data have led to unprioritized laundry lists of recommended studies and actions. We move beyond polarized positions regarding relevancy of genetic issues by assessing the published literature and 262 approved recovery plans for 642 federally listed plant taxa to determine whether taxa most at risk of extinction due to genetic factors (small or declining population size or numbers of populations or range size) receive more attention from conservation researchers and policy-makers. We then evaluate results and management applications of 108 publications on population genetic diversity in these species.
Results/Conclusions
We found that most species lack basic demographic and life-history information needed to understand genetic risk. For instance, population size and number of populations are simultaneously presented for <470 of 642 species with recovery plans. Key life-history features such as reproductive systems are also poorly understood, despite their dramatic impact on arrangement of genetic diversity and consequences of its loss. For taxa with data, recovery plans recommended genetic research for taxa with lower abundances (P<0.001), and declining population sizes (P=0.03), population numbers (P<0.001), and ranges (P<0.001). In contrast, published research focused on listed taxa with larger population sizes (P<0.001) and those that did not decline in number of populations (P=0.31) or range size (P=0.41). Therefore, agency personnel writing recovery plans better reflected the relative extinction risk of taxa with small and declining populations than did scientists. Further scientists could improve management application of population genetic studies by providing insight into ecological and evolutionary processes (particularly changes in historical processes) and better integrating neutral marker diversity with ecologically important traits or adaptation to local environmental conditions.
