Giant African snail (Achatina fulica (Bowdich, 1822)), an important invasive snail, was recently found in South Florida, USA. An extensive eradication effort was initiated consisting of pesticide applications, debris removal and hand collections. We studied the reproduction capacity and population dynamics of snails collected from 22 populations for two years to help evaluate the likely success of the eradication program. A total of 23,890 snails, ranging from 25–131 mm, were measured, dissected and the number of eggs in each snail counted. Gravid snails ranged from 48–128 mm. Only 5% of snails had eggs, which were found year round. As the snails increased in size, they were more likely to include reproducing individuals. However, the percentage of gravid snails peaked when snails were approximately 90 mm. Although more prevalent, small (<65 mm) adults contributed fewer eggs to the population than the larger snails. We evaluated the effect of control measures on six populations having >1000 adult snails and used data from the two largest populations to investigate how environmental factors (temperature, humidity, and rainfall) interacted with population dynamics and control measures. More snails were collected in weeks with high humidity and more gravid snails were collected when the temperature was higher. The addition of metaldehyde pesticides had the greatest impact on population dynamics by reducing snail numbers. In populations with fewer snails, their numbers were already declining before the use of metaldehyde, although the new treatment accelerated the process. As a consequence of the eradication program, egg-producing snails were no longer collected from most populations by the end of the study. The aggressive and persistent control efforts apparently lead to reduced populations of egg producing snails, eventually resulting in local extinctions of this important pest.

In pest eradication programs, traps can directly reduce pest populations; however, their application to gastropod programs remains relatively unexplored. The South Florida Giant African Snail, Liassachatina fulica (Pulmonata: Achatinidae), eradication program allowed a realistic evaluation of their utility. Field studies were conducted to determine the best bait, barrier and trap for use during the eradication program. Immature and adult snails were attracted to banana fruit and a commercially produced bait but only the commercially produced bait did not attract non-target and pest mammals. Four commercially produced traps and 4 barriers were field evaluated for snail retention efficacy. Snails escaped all traps and trap/barrier combinations but the rate of escape ranged from 10–100% after 24 hrs. Laboratory studies confirmed that snails can survive crossing a 5 cm barrier of copper tape, salt, insect stickem or antifouling paint. In the laboratory study snails did not cross copper sulfate but they crossed the barrier in the field. Adding salt to traps as a means to retain snails reduced the number of snails trapped. Laboratory studies confirmed that dry salt decreased the number of snails entering traps and snails did not enter traps when the salt was dissolved in water. Two trap types and the commercial bait were selected for a large-scale program test. For three months, trapping along with hand collection and pesticide application were conducted on 114 properties in five locations. Traps caught snails when surveys and regular pesticide applications on the same properties did not detect them. On 21 occasions snails were only found in traps, and both immature and adult snails were caught. This study showed that traps could be effectively deployed in an eradication program and they could capture snails that may have escaped other control measures.

Understanding long-term successional changes in old-growth forests affected by natural disturbance is particularly important in the context of contemporary climate changes. Quantitative descriptions of natural disturbance regimes require direct observations of tree populations over multiple decades, yet such studies are rare in the late-successional forest, particularly in the subalpine coniferous forest. Thus, we use four decades (1981–2022) monitoring of permanent plot in old-growth forest to reveal how tree species composition and structure changed. Results indicated that there was a significant decrease in the total density and basal area and standing volume, which was caused by the gradual decline of large Picea jezoensis var. komarovii. Meanwhile, Betula ermanii dominance increased over time. Analysis of spatial distribution patterns suggested that gap formation facilitated Betula ermanii adults and Picea jezoensis var. komarovii offspring naturally regenerate to coexist. Future canopy composition would mainly depend on a balance between Betula ermanii 's saplings probability of entering the canopy layer and the co-dominants’ survival there. Taken together, we concluded that the late-successional spruce-fir forest is dynamic and does not show quasi-equilibrial properties at a small scale, whereas, climax vegetation is a complex shifting mosaic that is comprised of patches in different successional stages. Natural disturbance is the main reason for maintaining the climax vegetation distribution pattern. In the absence of large catastrophic disturbances, we expect the mosaic pattern may persist for long under a certain climate regime.