Timeline Analysis & Climate Impact

Visual analysis demonstrating treatment effectiveness and rainfall adaptation - Marella Station (2020-2026)

Weed Coverage Progression vs Mackay Rainfall (2020-2026)
Treatment Frequency Response to Rainfall Conditions
Species Distribution by Year
Estimated Germination Pressure vs Seed Bank Depletion
Overall Program Effectiveness
89%
Total reduction from 2020 baseline despite challenging rainfall conditions (2021-2024 above-average years). Achievement demonstrates climate-responsive management can deliver results even during record wet periods.
Rainfall Challenge Overcome
2022
Record rainfall year (26% above Queensland average) created maximum germination pressure from drought-accumulated seed bank. Adaptive management maintained program trajectory despite "perfect storm" conditions.
Climate Adaptation Success
4 Years
Sustained above-average rainfall (2021-2024) required continuous treatment adaptation. Program flexibility allowed response to wet-year germination without compromising long-term goals.
Seed Bank Depletion
5 Years
Timeline to near-control aligns with lantana seed viability (3-11 years). Despite wet conditions promoting germination, consistent follow-up depleted viable seed reserves. Evidence: declining recruitment despite continued favorable moisture.
Program Metrics & Climate Context Summary
Total Area Managed
284 hectares
Baseline Infestation (2020)
65% Lantana + Other Weeds
Current Status (2025)
11% Total Coverage (Near Control)
Total Treatments (2020-2025)
13 Applications
Climate Period
Drought (2020) → Wet Cycle (2021-2024)
Mackay Average Rainfall
~1,200-1,585mm annually
2022 Rainfall Challenge
Record High - 26% Above QLD Average
Treatment Adaptations
Rainfall-Triggered Timing Strategy

Key Findings: Climate-Responsive Weed Management

1. Rainfall Directly Influences Treatment Success: The 2020-2026 program coincided with Queensland's transition from extended drought (2013-2020) to above-average rainfall (2021-2024). This created a unique challenge: drought-accumulated lantana seeds (viable 3-11 years) germinated en masse when wet conditions returned.

2. Record 2022 Required Adaptive Response: Queensland's wettest year since 2011 (26% above average) triggered peak germination pressure. Treatment frequency increased to target rainfall-triggered cohorts. Without adaptation, seed bank recruitment could have reversed Year 1 gains.

3. Sustained Wet Period (2021-2024) Management: Four consecutive above-average years maintained higher germination rates than typical. Program design accounted for this, scheduling treatments 5-10 days post significant rainfall (35mm+) to target actively growing seedlings when herbicide uptake is optimal.

4. Seed Bank Depletion Despite Favorable Conditions: By Year 5 (2025), recruitment declined significantly despite continued adequate moisture. This evidences successful seed bank depletion through consistent interception of germination cohorts before seed production.

5. Climate Variability Planning Essential: Mackay's rainfall varies significantly year-to-year. Multi-year programs must build flexibility to respond to both dry years (slower germination, extended viability) and wet years (rapid germination, intensive follow-up needed). This case study demonstrates successful navigation of challenging wet-cycle conditions.