Plant community and bare ground trends on Fort Riley, Kansas: Implications for monitoring of a highly disturbed landscape

• Published in: Transactions of the Kansas Academy of Science 2006-09, Vol.109 (3), p.101-119
• Main Authors: Althoff, Donald P, Gipson, Philip S, Pontius, Jeffrey S, Woodford, Philip B
• Format: Article
• Language: English
• Subjects: Ecological balance; Environmental aspects; Forbs; Forts; Grasses; Invasive species; Johnsongrass; Land Condition Trend Analysis (LCTA); Military aspects; Military bases; Military training; noxious plant species; Observations; Plant communities; Plants; point intercept method; Protection and preservation; sericea lespedeza; Species; species richness; Vegetation; Woodlands
• ISSN: 0022-8443; 1938-5420
• DOI: 10.1660/0022-8443(2006)109[101:PCABGT]2.0.CO;2

The Land Condition Trend Analysis (LCTA) program was developed by the US Army and implemented on Fort Riley, Kansas, to monitor trends in plant communities so that managers could maintain quality training lands without the loss of ecological diversity. As a standard protocol, vegetation surveys using the point-intercept method were conducted from 1994–2001. Presence of bare ground, soil erosion, and military vehicle traffic were also recorded. At the community level, species richness usually fluctuated < 10% annually and declined 6% from 1994–2001. Species richness per plot increased from 1994 to 2001 by 6.5% as compared to the 1994 estimate. Annual species richness of noxious plants ranged from 18–26 species; noxious species per plot averaged 1.0–2.4 species annually with higher estimates usually observed in grassland (vs. woodland) habitats. Modest year-to-year changes were noted at the species level for the most frequently observed species based on an index of relative difference. Two noxious plant species, sericea lespedeza (Lespedeza cuneata) and Johnsongrass (Sorghum halepense), first detected during the second year of monitoring, expanded their distribution considerably on the fort. This expansion may have resulted when mechanized training facilitated transport of seed on vehicles from one training area to another. The patterns of expansion (both on a plot and on a training area basis) by these two noxious species revealed that our analysis approach may be useful for detecting early stages of infestations on this highly disturbed landscape. Bare ground conditions increased on an average of 1.5% per year, but may not be completely attributable to military training activities. Because there appears to be little year-to-year fluctuation in the diversity of the plant communities and trends for most individual plant species monitored on Fort Riley, we recommend detailed plant surveys not be conducted annually. An exception would be monitoring of noxious plant species with a method other than the point-intercept technique, which is extremely time-consuming.