Native Aquatic Plant Establishment Efforts in a High-Herbivore, Central Texas Reservoir

Maintaining beneficial, native plant structure and diversity while reducing invasive, nuisance species dominance is an important management domain for natural resource managers. One such vegetation component in North American lakes and reservoirs is submerged aquatic vegetation—a valuable aquatic resource which serves as productive habitat for fish, aquatic macroinvertebrates, and other wildlife. Reservoirs in the southern parts of the United States have experienced varying aquatic plant dominance dynamics due to historical water resource management actions, including drawdowns and introduction of herbivorous fish for the purpose of controlling invasive aquatic vegetation. Some of these management options have also been detrimental to native submerged aquatic vegetation. This paper explores an adaptive management research effort by installing herbivore-protected, fenced-pen submerged aquatic vegetation sites in a high-herbivore reservoir to determine effectiveness of protecting habitat and serving as founder colony sources for propagule spread. Four experimental sites with three management treatments each were planted with American eelgrass. Each site utilized one un-fenced treatment and two treatments with varying mesh sizes for protective fencing-pens. Site integrity, species survival and spread, and grazing were documented. One additional site was installed and planted with other native submerged aquatic vegetation species for nominal species performance descriptions. No plants survived unprotected in the high-herbivore system and plants, in general, performed consistently better within the smaller mesh size. These test planting results were ultimately used to inform adaptive management decision making for plant installation and expansion designs for managing reservoirs invested with Hydrilla, considered one of the most serious invasive aquatic plants in the United States.

Manipulated microtopography alters plant community development in fragile farm-pastoral transition zone

The ecosystems within agro-pastoral transition zones exhibit inherent fragility and heightened susceptibility to climate variability,exacerbated by profound degradation resulting from anthropogenic activities.Subsequent vegetation degradation in these areas precipitates severe soil erosion,presenting formidable challenges for ecological restoration efforts.The utilization of microtopographic structures to mitigate soil erosion and facilitate vegetation recovery stands as a prominent strategy for vegetation restoration within agro-pastoral transition zones.Despite the acknowledgment in current restoration practices that the efficacy of microtopography-based restoration is contingent upon slope,aspect and elevation,there remains a notable absence of precise observed information on this correlation.This study,conducted in the Bashang Grassland,a typical agro-pastoral transition zone in northern China,aims to fill the information gap concerning the correspondence between microtopographic structures and restoration outcomes.Our findings revealed that microtopography has a significant impact on vegetation characteristics,with outcomes varying by location.Shaded slopes displayed higher biomass and density compared with sunny slopes and valleys.While microtopography affected community structure,it did not substantially alter species richness,highlighting the critical role of location and pit construction in successful restoration endeavors.This study provides insights for the selection,design and assessment of microtopography-based restoration in vulnerable ecosystems.