@article {JRN55413, title = {Simulated distribution of Eragrostis lehmanniana (Lehmann lovegrass): Soil{\textendash}climate interactions complicate predictions}, journal = {Ecosphere}, volume = {13}, year = {2022}, month = {3/7/2022}, pages = {e3974}, abstract = {The invasive perennial grass Eragrostis lehmanniana has expanded rapidly throughout the Sonoran Desert (SD) while remaining sparse and patchily distributed in the neighboring Chihuahuan Desert (CD). As temperatures and patterns in precipitation change, identifying the drivers limiting spread in the CD is needed. Our objectives were (1) to identify the climatic and edaphic factors limiting recruitment of E. lehmanniana throughout the CD and (2) to predict the edaphic and climatic locations in the CD where this species is expected to have higher probabilities of recruitment under future climatic conditions. Recruitment was simulated at 57 locations throughout the CD with a daily, multilayer soil water model (SOILWAT) that was parameterized and tested to develop recruitment parameters for E. lehmanniana using long-term data from research stations in the SD and CD. Logistic regression was used to predict recruitment across the CD using climate and soil factors to create a map of simulated recruitment under current and alternative climate scenarios. Simulated recruitment under current climate was low for most of the CD. However, localized areas with high probabilities (>0.8) occurred along the western transition between the CD and the SD, and in the southern extent of the CD. In general, the CD climate is too cool and dry for rapid and widespread invasion. However, increases to temperature and precipitation are likely to increase recruitment success. Interactions among soil, tempera-ture, and precipitation were important to increases in recruitment of E. lehmanniana and are expected to lead to heterogeneous increases in abundance as climate continues to change. This patchy increase in abundance will result in changes in its geographic distribution that will make predictions in the future challenging.}, keywords = {Chihuahuan Desert, climate change, Geographic distribution, numerical model, recruitment, seedling establishment, Special Feature: Dynamic Deserts}, doi = {10.1002/ecs2.3974}, url = {files/bibliography/22-022.pdf}, author = {N. Dylan Burruss and Debra.C.P. Peters and Haitao Huang and Jin Yao} } @conference {50484, title = {Changes in Perennial Grass Recruitment From 1858 to Present Following Woody Plant Invasion}, booktitle = {91st Ecological Society of America Annual Meeting}, year = {2006}, month = {August 6-11, 200}, pages = {99}, address = {Memphis, TN}, abstract = {Desert ecosystems of the American Southwest have experienced dramatic changes in vegetation structure and soil properties over the past several centuries with the expansion of native woody plants. This conversion from perennial grasslands to shrublands is often difficult to reverse as a result of soil degradation and low grass seed availability. Additional recruitment processes that can limit the return of grasses are seed germination and seedling establishment, processes that are affected by both soil properties and vegetation structure. Our objective was to examine and compare the probability of recruitment of the perennial grass, Bouteloua eriopoda (black grama), in 1858 and at present using the simulation model of daily soil water dynamics. We used the model to simulate recruitment probabilities of black grama for the variation in conditions found at the Jornada Basin ARS-LTER site in southern New Mexico. Vegetation and soils maps for both time periods and historical weather data were used to parameterize the model. In general, simulated recruitment probabilities were higher in 1858 when the Jornada was dominated by grasslands compared with the present, shrub-dominated system. Because recruitment of black grama is nonlinearly related to silt content of the soil and to aboveground plant cover, these changes in recruitment probabilities were dependent on location-specific changes in soil properties and vegetation cover. Our results were used to identify the locations and conditions where recruitment of black grama is still possible; these areas can then be targeted for remediation efforts. We also identified the locations where remediation efforts of this grass species will fail without significant modifications to soil properties and vegetation cover. This approach to stratifying landscapes by recruitment potential can be used for other invasive species.}, keywords = {1858, grasslands and shrublands, modeling, perennial grass, Present, recruitment, woody plant}, author = {Debra C. Peters and Curtis H. Monger and Jeffrey E. Herrick} } @article {51142, title = {Demography of Bouteloua gracilis in a mixed prairie: analysis of genets and individuals}, journal = {Journal of Ecology}, volume = {87}, number = {2}, year = {1999}, month = {April 1, 1999}, pages = {233-243}, abstract = {

1 We analysed a data set containing the locations and sizes of individual plants from five 1-m2 permanent quadrats that had been mapped annually from 1934 to 1972. We digitized each map and used geographical information software to evaluate annual recruitment and mortality, age structure, survivorship and longevity of genets and individuals of Bouteloua gracilis.

2 Ninety-one per cent of the years between 1938 and 1972 had at least one seedling recruited. An average of 10.3 genets died annually, although the variability among years was high (CV\ =\ 70\%). The number of seedlings recruited each year was significantly correlated with the number of genets dying. Most genets died before age 10 and the average life span was 3.7 years, although some genets were much longer lived (\>\ 38 years).

3 The average number of individuals per genet was 1.3. Excluding seedlings, 56\% of the genets were represented by a single individual. The annual number of individuals in the 5\ m2 ranged from 29 to 278. Average mortality of individuals was 25.8 per year and the variability among years was high (CV\ =\ 91\%).

4 The plant community appeared to be relatively stable and openings created by mortality were recolonized by recruitment. Climatic variability did not have a large influence on demography.

}, keywords = {clonal fragmentation, grassland, mortality, plants, recruitment}, doi = {10.1046/j.1365-2745.1999.00344.x}, url = {/files/bibliography/653.pdf}, author = {J.L. Fair and W. K. Lauenroth and D.P. Coffin} }