71 BURDEKIN DRY TROPICS NATURAL RESOURCE MANAGEMENT PLAN 2016-2026
BIODIVERSITY
A prickly acacia stronghold at Inkerman Station was successfully controlled thanks to collaboration between Burdekin Shire Council, NQ Dry Tropics, State Government and a dedicated landholder.
The partnership regained control of the land and improved its overall productivity by establishing a Property Pest Management Plan.
They trialled various approaches to tackle the problem, including:
• using an Ellrott blade plough and cutter bar to suit different conditions;
• carefully-timed aerial seeding; and
• fencing stock away from weeds.
from feral animals;
• soil erosion;
• sedimentation or erosion of watercourses and wetlands;
• eutrophication in wetlands; and eventually
• pollution of marine waters that support the GBR.
1. Native vegetation clearing and condition
The single most significant cause of biodiversity decline is loss of habitat, particularly through the clearing, fragmentation and degradation of native vegetation. Maintaining and improving the integrity( extent, distribution, connectivity and condition) of native vegetation at landscape and catchment scales continues to be a priority for biodiversity in our region.
The Burdekin catchment has been subjected to a significant level of clearing in some areas, while other areas are less affected and only show pockets of clearing. The Upper Burdekin retains greater than 90 per cent remnant vegetation, however coastal areas and large tracts of land in the Belyando and Suttor catchments have been cleared. Coastal areas are also extensively cleared, with the main native vegetation remnants being riparian and coastal wetlands and in non-arable hill country. With the exception of town centres, the majority of past clearing was undertaken for grazing and irrigated cropping. In total 25.5 per cent or 36,000 km 2 of the Burdekin catchment has been cleared with the Belyando and Suttor catchments having only 50 per cent and 53 per cent respectively of vegetation cover remaining( Queensland Herbarium, 2015).
The major impacts of past clearing include:
• soil erosion;
• loss of species diversity and localized extinction and changes in biodiversity composition;
• loss of ecosystem function;
• fragmentation of corridors and loss of contiguity;
• changes to water balance, particularly groundwater, with implications for dryland salinity; and
• reduced buffering capacity against other threatening processes.
2. Weeds and feral pests
The proliferation of non-native plants, and the unnatural spread of some native plants, leads to multiple impacts that affect the overall biodiversity of our region. They have dramatic effects on vegetation structure, proportional abundance of species, water flow characteristics and quality, aquatic flora and fauna, and ecosystem processes. They occur in terrestrial systems from savannas, scrubs and rainforests through to aquatic areas such as riparian zones and wetlands. Riparian zones are especially susceptible to colonisation and spread of certain weeds because water and nutrients are in greater supply in these areas.
Weeds have been introduced either historically as a food source for humans and livestock, or as gardening plants that subsequently spread into natural environments. Illegal dumping, especially of household green waste in natural areas, helps to spread weeds and diseases into rural areas, which can significantly impact on the natural ecology as well as the productivity of agricultural enterprises.
Populations of feral pigs, deer, horses and rabbits have all been listed as priority species in the our Burdekin Dry Tropics Regional Pest Management Strategy. The EPBC Act recognises impacts particularly from feral cats, pigs, foxes, tilapia and rabbits, as key threatening processes. In general, feral animals:
• outcompete native species for resources;
• reduce landscape resilience;
• disturb the ground;
• damage vegetation communities;
• destroy culturally-sensitive areas;
• spread weed seeds;
• consume small vertebrates and eggs( for instance, native frogs and lizards);
• spread disease;
• pollute and damage riparian and wetland areas; and
• impact on agriculture and other industries.
The Biosecurity Act 2014 provides the statutory direction for managing pests in Queensland. However, the resources available for managing pest plants