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Invasive plants decrease biodiversity, modify vegetation structure, and inhibit growth and reproduction of native species. Japanese honeysuckle (Lonicera japonica Thunb.) is the most prevalent invasive vine in the forestlands of eastern Texas. Hence, we aimed to identify potential factors influencing the distribution of the species, quantify the relative importance of each factor, and test possible management strategies. We analyzed an extensive dataset collected as part of the Forest Inventory and Analysis Program of the United States Department of Agriculture (USDA) Forest Service to quantify the range expansion of Japanese honeysuckle in the forestlands of eastern Texas from 2006 to 2011. We then identified potential factors influencing the likelihood of presence of Japanese honeysuckle using boosted regression trees. Our results indicated that the presence of Japanese honeysuckle on sampled plots almost doubled during this period (from 352 to 616 plots), spreading extensively, geographically. The probability of invasion was correlated with variables representing landscape conditions, climatic conditions, forest features, disturbance factors, and forest management activities. Habitats most at risk to invasion under current conditions occurred primarily in northeastern Texas, with a few invasion hotspots in the south. Estimated probabilities of invasion were reduced most by artificial site regeneration, with habitats most at risk again occurring primarily in northeastern Texas. [ABSTRACT FROM AUTHOR]

Chinese privet (Ligustrum sinense) was the most prevalent invasive shrub in the forestlands of Eastern Texas in 2006. We analyzed extensive field data collected by the Forest Inventory and Analysis Program of the U.S. Forest Service to quantify the range expansion of Chinese privet from 2006 to 2011. Our results indicated the presence of Chinese privet on sampled plots increased during this period. Chinese privet spread extensively in the north. Results of logistic regression, which classified 73% of the field plots correctly with regard to species presence and absence, indicated probability of invasion was correlated positively with elevation, adjacency (within 300 m) to water bodies, and site productivity, and was correlated negatively with stand age, site preparation (including clearing, slash burning, chopping, disking, bedding, and other practices clearly intended to prepare a site for regeneration), artificial regeneration (which refers to planting or direct seeding that results in at least 50% of the stand being comprised of stocked trees), and distance to the nearest road. Habitats most at risk to further invasion (likelihood of invasion > 40%) under current conditions occurred primarily in Northeast Texas. Practicing site preparation and artificial regeneration reduced the estimated probabilities of further invasion. [ABSTRACT FROM AUTHOR]

Chinese tallow (Triadka sebifera [L] Small) was the most prevalent invasive tree in the forestlands of eastern Texas in 2006. We analyzed an extensive data set collected as part of the Forest Inventory and Analysis Program of the USDA Forest Service to quantify the range expansion of Chinese tallow from 2006 to 2011. Our results indicated that the presence of Chinese tallow on sampled plots doubled during this period. Chinese tallow spread extensively toward the north. Results of multiple logistic regression, which classified 71% of the field plots correctly with regard to species presence and absence, indicated that the probability of invasion was correlated positively with mean daily minimum temperature, elevation, adjacency to water bodies, and site productivity and was correlated negatively with stand age, site preparation, artificial regeneration, and distance to the nearest road. Habitats most at risk of further invasion (likelihood of invasion >20%) under current conditions occurred primarily in northeastern Texas, with a few invasion hotspots in the South. Estimated probabilities of further invasion were reduced the most by site preparation and artificial regeneration, with habitats most at risk again occurring primarily in northeastern Texas. [ABSTRACT FROM AUTHOR]

The Mexican prairie dog (Cynomys mexicanus) is an endangered species that is endemic to the northeastern Mexico states of Coahuila, Nuevo Leon, and San Luis Potosi. We provide descriptions of historical, recent, and current distributions of this species by integrating available distributional information from the literature, museum records, and new field observations. We estimate current, recent, and historical ranges as 478, 768, and 1,255 [km.sup.2], respectively, indicating the Mexican prairie dog has lost 62% of its historical natural habitat as large and medium-size colonies have been fragmented into numerous small isolated colonies. Seventy-four percent of the current geographical range is in Nuevo Leon (354.7 [km.sup.2]), 24% in Coahuila (112.5 [km.sup.2]), and 2% in San Luis Potosi (9.5 [km.sup.2]). We located 88 active and 6 inactive colonies. Active colonies are larger, less isolated, and better connected than inactive colonies. Size of active colonies is correlated with density of active burrows and an index of connectivity. Key words: Cynomys mexicanus, Mexican prairie dog, geographic distribution, habitat fragmentation, conservation status