Dynamics of the Woody Vegetation Along the Arkansas River in Western Kansas, 1870-01/01/1983

Prior to 1880, the Arkansas River in western Kansas averaged 400m in width, and supported almost no riparian forest. The flow regime and the consequent geomorphology of the river were hypothesized to be the most important forces that restricted the growth of woody vegetation on the banks of the river. The subsequent influx of trees into the channel during the 20th century is correlated to the onset of irrigation, as the reductions in peak discharges enabled tree seedlings to become established in the channel. Until the turn of the century, farmers used only the surface flows of the river to irrigate. Irrigation with groundwater, and the construction of John Martin Reservoir on the upper Arkansas in 1943, also affected the flow regime and shrinkage of the channel. The woody vegetation in the valley probably reached a peak in areal extent during the late 1960\u27s. Since 1970, exploitation of groundwater has dried the river through an 80 km reach, and has severely curtailed the establishment, growth, and survival of trees

A field guide to Montana fishes /

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Conservation of the Conchos Trout: a white paper on history of its discovery, report on its status, and an urgent plea for action

originally published at http://www.fishesoftexas.org. See also subsequent publication with updates as a book chapter: Hendrickson, Dean A., D.A. Neely, Richard L. Mayden, K. Anderson, J.E. Brooks, Faustino Camarena-Rosales, R. Cutter, et al. 2007. “Conservation of Mexican Native Trout and the Discovery, Status, Protection and Recovery of the Conchos Trout, the First Native Oncorhynchus of the Atlantic Drainage in Mexico.” In Studies of North American Desert Fishes in Honor of E. P. (Phil) Pister, Conservationist. Monterrey, Nuevo León, México: Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas.A broad-scale survey of potential trout habitats in upper tributaries of the Río Conchos of Chihuahua, México resulted in the re-discovery in 2005 of a long-lost native, endemic, and now endangered, undescribed trout species that we call the “Conchos Trout.” We are currently in the process of scientifically describing this rare trout, the only native Mexican trout known from an Atlantic drainage. Our extensive field efforts to date clearly indicate that this species was formerly much more widely distributed historically. Though surveys should continue, our extensive field surveys found only one small isolated and extremely vulnerable population, leaving us less than optimistic that many other, if any, additional populations will be found. Persistence of this new critically endangered endemic Conchos Trout clearly requires rapid conservation action. Our consensus expert opinion is that we cannot over-emphasize the urgency of protection for this critically endangered population of this unique trout, and so we have produced this “white paper” in hopes that it might encourage others to join us in initiating appropriate conservation programs. The potentially viable population is restricted to a short reach of a very small stream where it and another newly discovered, undescribed fish species, a sucker (and likely another unique taxon), could be relatively easily protected, studied and managed. Additionally, adjoining arroyos where the species recently occurred offer the possibility of restoring native fish populations to them following appropriate protection and habitat restoration efforts. All members of our highly qualified and diversely specialized, binational “Truchas Mexicanas” team stand prepared to join collaborators and invest personal resources in hands-on actions to help this new species persist. We recommend immediate establishment of a small reserve centered around currently occupied habitat and adjacent streams having suitable habitat, combined with education and compensation of local residents for their cooperation with reserve management. We recognize that we are largely ignorant of the local political and cultural systems via which conservation actions will have to proceed and are limited with regard to our ability to raise funds. We thus hope that readers of this white paper will add their financial and in-kind support and additional expertise to help us conserve the Conchos Trout!Texas Natural Science Cente

Conservation of Mexican native trout and the discovery, status, protection and recovery of the Conchos trout, the first native Oncorhynchus of the Atlantic drainage in Mexico

The Northwestern Sierra Madre Occidental of Mexico is a rugged mountain range covering portions of Sonora, Chihuahua, Durango and Sinaloa, and is drained by multiple Pacific Slope Rivers to the west and the Casas Grandes, Conchos, and Nazas to the east. The overall area is topographically, climatically and biotically diverse, ranging from endorheic basins (Casas Grandes) to mountainous areas elevations up to 3348 m, average mean temperatures from 10-20°C and precipitation from 250-1100 mm/yr. The region is also geological complex that, combined with these other variables, provides a great diversity of both aquatic and terrestrial habitats conducive to both biotic endemicity and diversity. The overall diversity of the region has contribiited to the recent listing of this region by Conservation International as one of six new high-priority biodiversity hotspots. Our understanding of the aquatic and terrestrial biodiversity of this region, however, is poor and in urgent need of rapid investigation by collaborative communities. The combination of an incredibly rugged landscape, drug and bandit activities and indigenous peoples that have not always been welcoming to visitors has resulted in a general paucity of roads in the region, and the lack of access has limited inventory studies. Recently, however, access to the region has changed dramatically and many of the areas are now accessible enough for logging, mining, and agriculture practices, all exerting extreme pressures in some areas on the biodiversity. In addition to human-induced changes to these diverse ecosystems, impacts of invasive aquatic species are becoming more and more apparent, and the potential for severely reducing population sizes of species or their extirpation or extinction is real. While several invasive or exotic species are identified as potentially destructive to these communities, the exotic Rainbow Trout (Oncorhynchus mykiss) that is derived from hatcheries or culture facilities within the region represents one of the most critical threats to the aquatic and semi-aquatic biodiversity. The native trout of mainland Mexico represent the southern- most salmonids, and are at imminent risk of introgression and/or replacement by feral Rainbow Trout, Oncorhynchus mykiss. Our recent survey efforts have expanded the known diversity and ranges of each of several distinct forms, which we feel represent valid species. We discuss our discovery of multiple new species from the Sierra Madre Occidental and focus on a new species of trout restricted to the upper Conchos drainage, the first native species of Oncorhynchus known to occupy the Atlantic Slope in Mexico. Many of these taxa are restricted to small areas of intact habitat in headwater areas of high-elevation streams, and are at risk from a suite of human-associated perturbations, emerging diseases, and introduced species. These fishes occupy unique habitats, and represent a diverse portion of the Mexican montane ichthyofauna. The habitats on which they depend support a wide range of other aquatic organisms, most of which are grossly understudied. The discovery of the Conchos Trout derived primarily by GARP niche modeling of a subset of localities of previously sampled undescribed native Mexican trout, provides only a snapshot of the biodiversity awaiting to be discovered in this region. The rugged landscape of the Sierra Madre Occidental simply precludes routine sampling at easily accesible locations of streams and most sampling locations require time-intensive access. In an effort to rapidly assess the biodiversity of rivers of this region we employed this method to aid in predicting the most suitable and highly probable Mexican trout niches in the region. This method offered highly efficient and powerful results that not only predicted the occurrence of a previously unknown trout in the upper Rio Conchos but also provided excellent predictions of available habitats in drainages where previously unknown trout have been discovered by the Truchas Mexicanas team in the last nine years. Multiple threats exist to the biodiversity of the northern Sierra Madre Occidental, including uncontrolled introductions of exotic and invasive species, emerging diseases such as whirling disease, Myxobolus cerebralis, infectious pancreatic necrosis (IPN), iridioviruses and pathogenic water mold, Saprolegnia ferax, land-use practices leading to habitat degradation via overgrazing, logging, deforestation and road construction, increasing human population growth, over-fishing or overharvesting of aquatic resources and global climate cliange reducing surface and ground water in the area and creating environments more conducive to the spread of invasive species, congregated and dense human populations, and emerging diseases. Immediate actions need to be developed to aid in public education as to the threats to these ecosystems, protection of areas, assessment of diversity, and sustainable development throughout the region that incorporates a likely highly successful ecotourism system for the region.Integrative Biolog