ENV334 Restoration Plan PDF

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RESTORATION OF A THREATENED BANKSIA WOODLAND SITE IN MURDOCH UNIVERSITY

Shendell Hay (32670761) & Nicholas Griffith (33548204)

Word Count: 3766

Introduction Biodiversity hotspots are identified as regions on Earth containing the richest endemic species under threat. Among these 25 global biodiversity hotspots, the South-West Australian Floristic Region (SWAFR) is listed as one of them (Hopper & Gioia, 2004). The SWAFR is significant internationally as Australia’s sole biodiversity hotspot. This region supports remarkable biodiversity within Banskia woodlands, which are the dominant vegetation of the Perth region (Brown & Gibson, 2014). Banksia woodlands in the Swan Coastal plain (a subregion of the SWAFR) are typically compromised of a prominent banksia canopy layer, with eucalyptus trees and other native species dispersed sparingly within or rising above their tree layer. A species rich understory is usually prevalent within these woodlands which include sclerophyllous shrubs, graminoids and forbs. Expanding urbanisation is the leading cause of the rapid and extensive loss of native vegetation and its fragmentation into small and isolated urban remnants (Ramalho et al, 2014). Within the Perth Swan Coastal plain it is estimated that 85.5% of these banksia woodlands had already been cleared by 1986 (Hercock, 1997). As stated by Ashwood et al (2019), “woodland restoration is underway globally to counter the negative soil quality and ecological impacts of agricultural expansion and woodland fragmentation, and restore or enhance biodiversity, ecosystem functions and services”.

The Murdoch University Banksia bushland is one of Perth’s remaining areas of fragmented banksia woodlands and is managed by Murdoch University with traditional ownership 1

recognised as belonging to the Whadiuk Noongar people. Farming and arboriculture caused disturbance within these woodlands, and what remains are small but significant areas of the original bush (Dell & Bennett, 1986). The site depicted in figure 1.0 (b) resides in the Beeliar Wetlands and is a small, fragmented site within the Murdoch University banksia woodland. This site was once abundant in native flora and fauna species, but has now been identified as being especially under threat due to fragmented segments having become overrun with invasive species and segmented by man-made dirt tracks and cleared agricultural land (Brundrett et al. 2016) . As one among many of Perth’s threatened banksia woodlands, successful restoration of this site can be utilised in the research of further application methods.

The goals for the restoration of this banksia woodland site will focus on reducing negative human impacts, reduce density of invasive species, and increase abundance and health of native species by 80%. The restoration objectives for reducing negative human impacts associated with this site location will be to diminish the occurrence of; pollution from litter, damage and erosion caused by human and vehicle traffic, and the transfer of fertilisers, chemicals, and foreign plants into the woodland from the surrounding agricultural properties. 2

The Perennial Veldt Grass (pictured in Figure 2) was identified as the principal problematic invasive species within the location, with an estimated 60% of the site being populated by this one species alone. The objectives to successfully reduce this species abundance in the site will include physical removal of the veldt grass plants and topsoil transfer. Once successful, the restoration goal of increasing abundance and biodiversity of native species will be undertaken with the objectives being to acquire seedlings of native species from nurseries, planting of the seedlings and implementing adequate care until the seedlings are well established.

These restoration goals and objectives will be undertaken over the course of a 3-year period with an approximate $90,000 budget. Scheduling the tasks required for the restoration of this site location will be inclusive of preparation tasks, planting tasks, monitoring and upkeep tasks and consider seasonal requirements such as watering schedules in summer versus winter, appropriate planting season, flowering season of invasive species. Criteria has been outlined to define what would be considered a success in terms of restoration objective completion. This provides a guideline for the project which allows for a review at the end of the 3 year period to determine the site as being successfully or unsuccessfully restored.

Plan and Implementation (34 -37) 3

34. Describe the interventions that will be implemented to attain each objective. Strategic implementation of interventions will be required to achieve successful restoration objectives at the end of the 3-year time period. The detrimental effect of human impacts to the ecosystem will need to be subdued in the first instance to prepare for the rehabilitation of the site. The close proximity of this site to agricultural land and urban development increases the occurrence of litter and chemical pollution, and physical damage in the ecosystem. As summarised in Table 1, there will be three main objectives to minimise these human impacts. Reducing rubbish pollution will be addressed by the initial physical collection and removal of all visible litter in the site. Gloves and garbage bags will be utilised to collect rubbish by hand until there is no visible litter left on site. This aims to reduce the potential of chemical release which can be absorbed by the soil and harm to native fauna. This will be monitored for the course of the project with 6-month check-ups and spot removals of rubbish. Restriction of vehicle and human access to the site will be implemented by a complete restriction on unauthorized vehicles and human entry into the site. The installation of fencing around the entire site with a locked gate entry for restorative purposes only will aim to minimise damage and disturbances to the ecosystem caused by vehicles and humans trampling native vegetation and leaving behind pollutive wastes. This is particularly effective in ensuring fragile native seedlings aren’t at risk of being compromised before they have had adequate time to grow into larger, more established plants. The fencing will be lined with green mesh which will also aid in decreasing the transfer of seeds, foreign species and pollutants into the site from bordering agricultural lands. Ensuring the gate entrance to the site remains locked at all times, and a check-up every 6 months to identify potential damage in the fence or mesh will aim to maintain the effectiveness of the fencing.

Table 1: Restoration plan goal #1: Reduce undesirable human impacts from nearby residential and agricultural lands. Objectives Reduce visible rubbish

Restrict traffic Vehicle and human

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Rationale Visibly undesirable. Potential for chemical release, animal harm, pollution. Traffic stepping on flora & fauna causing damage. Reduce rubbish input. Restrict access to the

Success Criteria Day of physical rubbish removal, rubbish is not extreme.

Monitoring Protocol 6 Monthly check of visible rubbish.

100% Restriction on unauthorized vehicle entry into the bushland and 100% restriction of

Locked gate entrance to the restoration site

Reduce nutrient & seed input from nearby agriculture lands

area to stop disturbances and rubbish. Nutrients & chemicals cause harm to residing species. Seeds of weeds reduce native land. Fine meshed fence will restrict seed input via wind after topsoil transfer.

humans into the fenced area. Fence installed within 3 months with fine mesh installed to stop seed spreading.

6 Monthly check to inspect fence damage, holes in or under.

After minimising the effects of human impacts, the reduction of invasive species with a focus on the Perennial Veldt Grass in the site will be the second goal focused on in the restoration of this banksia woodland. Initially, the intent will be to physically remove 100% of all visible weeds in the area. Gloves and shovels will be used to physically remove each plant by the roots, before placing them in large garden bags and being taken off site. The high abundance of the veldt grass in the woodland has resulted in the competition for resources with native species. As a consequence, native species have reduced health and limited area to grow resulting in a decrease in biodiversity and native species abundance. With an initial 100% reduction in visible weeds, followed with monthly inspections, the success criteria will be a reduction in all exotic species by 80% over three years. This will aim to decrease the competition for resources, and increase available soil for native species to establish and grow. With the removal of invasive species, there is potential for seeds to be left behind in the soil and grow into new weeds. A topsoil transfer will take place to reduce the reoccurrence of these weeds, and further diminish any pollutants in the soil from human impacts. Contaminated soil will be removed and replaced by a cleaner, nutrient rich substrate. The new topsoil will aid in the planting and establishment of native plant seedlings.

Table 2: Restoration plan goal #2: Reduce presence of Perennial Veldt Grass & their exotic species by 80% to create a more suitable site for long-term native species development relative to its previous state before human impact. Objectives Rationale Success Criteria Monitoring Protocol Physical removal of weeds Outcompeting native 100% Reduction of Monthly inspections – Main weed is veldt grass species causing reduced visible weeds initially. for regrowth of health and area to grow. 80% Reduction in overall weeds. exotic species by 3 years. Monthly inspections Within the fenced zone Topsoil transfer Reduce seedbank for regrowth of around trees & large abundancy, a topsoil native species, 90% of weeds. transfer will remove the topsoil to be transferred. contaminated soil and Limited regrowth of replace with a cleaner weeds. substrate ready to replant.

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The final goal for this restoration project is to increase the abundance and health of native species by 80% over the course of the three years, as summarised in Table 3. The prior removal of invasive species and topsoil transfer will provide a suitable environment for the establishment of native seedlings. A selection of seedling species will be chosen for planting to ensure a diverse range of native flora are established in the ground cover, understory, and canopy layers. Seedlings were chosen for the purpose of this restoration project as they have prior established root systems which will increase the likelihood of success in planting when compared to seeds. Established plants are easier to locate for watering and enables the strategic and specific placement of each plant. Seedlings will be planted in the winter to reduce the impacts of hot weather conditions such as harsh direct sunlight, high temperatures, low rainfall, and dry soils. Planting in winter also reduces the need for hand watering in the initial seedling stage. Increased rainfall and subdued weather conditions will increase the survival rate of the seedlings. With regular watering and maintenance, accompanied with the replacement of deceased seedlings, a successful increase in abundancy of native species by 80% is expected by the end of the 3 years. Table 3: Restoration plan goal #3: Increase native species health and abundancy by 80% after 3-years. Objectives Native species collection and nursery

Plant all native stock in Winter

Native species to have a solid root system and grow healthy.

Rationale

Success Criteria

Collect saplings of native species and cultivate ready for planting. Saplings chosen as they have a root system already. With increased rainfall and less harsh conditions Winter will be the best time to plant.

80% of planted native species to survive after 3 years.

Plants cannot simply be left by themselves once planted young, constant monitoring until matured is a must.

35. Acknowledge the role of passive restoration.

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80% of fenced area once covered in veldt grass to be replaced with native species. 80% of planted native species to survive after 3 years.

Monitoring Protocol Regular watering & maintenance. Replanting dead plants. Regular watering, maintenance.

Regular watering & maintenance. Replanting dead plants.

Once active restoration goals have been implemented, it is expected that passive restoration processes will further aid in the successful rehabilitation of this banksia woodland site. With the removal of high-density exotic species such as the veldt grass, a greater area of available soil will allow for the increased growth of existing native species, along with the successful reproduction of new native seedlings into the soil. The topsoil transfer will also increase soil quality, which in effect will increase the health of existing plants and likelihood of successful natural reproduction by these plants. Increased natural abundance by the expansion of established plants will further increase the biodiversity and ecosystem health. It can be expected with the increase in biodiversity and native species abundance in the site, native fauna will be attracted back into newly stable ecosystem – further aiding in restorative health of the site. Native fauna can assist in the transfer and depositing of seeds and pollens of endemic plant species which passively aids in increasing the population of native species. Wastes produced by fauna can also increase the nutrient richness of the soil, further aiding the health of the native plants.

36. Prepare performance standards and monitoring protocols to measure the attainment of each objective.

To achieve the maximum success possible this project must have performance standards and monitoring protocols put in place pre-restoration. When looking at performance standards, the end goal will be restoring it to a close approximation of its original condition preintroduction of exotic species. The important part is to be realistic in the fact there is potential for exotic species to survive the soil transplant and continue to re-grow. Regular monitoring will ensure not only newly planted native species health, but to inspect the overall area for exotic species to remove. Objective to reduce visible rubbish, performance standards will include 100% of visible rubbish to be removed initially as there is a low level of rubbish at the site. Furthermore monitoring protocols will include a 6-monthly day of rubbish inspection and removal to see if, or how it can get through the fence. Due to the meshed fence next to an open agricultural land, expectations of wind blowing rubbish into the fence are apparent along with other objects. 7

Restrict human and vehicle traffic, the restoration site is located in a relatively low traffic location which is helpful, there are currently gates surrounding the woodlands allowing human traffic through. Road traffic is limited to those with access with keys, unsealed roads line the site allowing only 4x4’s through the soft sand. Monitoring protocols will include inspections during initial watering phases, then moved to 6-monthly periods in conjunction with rubbish inspection. Reducing nutrient and seed input from the nearby agricultural lands will be monitored via the number of exotic species growing post-removal of physical plants and planting of new native species. When looking at performance standards, the end goal will be restoring it to a close approximation of its original condition pre-introduction of exotic species, so removal of 100% initial exotic species and 80% after 3 years.

Performance standards for the topsoil transfer will be tricky, the build up of seed banks from veldt grass is the main priority for the transfer. Monitoring at regular periods during watering days will monitor for regrowth of veldt grasses, then removal if necessary. Correlating with reducing nutrient and seed input with be for 100% initial removal of exotic species and 80% reduced at the 3-year period.

Planting the native saplings will be monitored initially via weekly watering and inspections for the first 3 months, then extended to fortnightly for the next 12 months. Once established after 15 months, monthly watering inspection days will follow for the next 12 months. Saplings will be planted in Winter to take advantage of rainfall and reduced temperature, although subject to inspections watering days can extend, or reduce if necessary.

37. Schedule the tasks needed to fulfil each objective The restoration schedule is inclusive of pre-planting, planting, and post-planting monitoring tasks throughout a 3-year period. Pre-planting tasks include the time necessary to pick up all consumables and saplings from shops plus the removal of all exotic weeds and rubbish at the restoration site. Once the site has been cleared of weeds and rubbish, the topsoil transfer can be completed while keeping current native species disruption to a minimum, residing natives 8

are mainly large trees. Once all major disruptions have been completed, the fence will be fitted along with a gate and large locks to keep the general public as much as possible (figure 6).

The actual plantation of natives will include digging a small hole per plant, placing a small amount of fertilizer at the bottom, placing the plant, mounting corflute guards, and finally watering. Post-planting maintenance will vary time-wise throughout the 3-year period, weekly watering will be undertaken for 3-months then fortnightly for 12-months then monthly for 12-months. At the end of the 3-year period an analysis will be undertaken to determine when watering and inspections will be undertaken from then on. Watering and inspection days include tasks such as: Watering, replacing dead plants, trimming dead parts and flowers to ensure energy is sent towards growth plus fence and site maintenance (figure 6).

Figure 6: Banksia Woodland restoration Gantt schedule. (176 Words)

The budget for the restoration plan includes immediate costs to plant the saplings, this includes 3360 individual tube saplings with young root structures. The site area is 9,600m2, minus 30% accounting for current native species leaving 6720m2 for planting with one plant per 2m2. The budget allows further contingency costs for replacing dying plants via regular Tube saplings are from: Muchea Farmfertilizer | https://mucheatreefarm.com.au/ monitoring if sourced necessary, alongTree with and other consumables that may be necessary Remaining budget will contribute towards any contingencies, beyond budget for maintenance and any gaps in budget. 1 https://fernland.com.au/25kg-8-9-mth-osmocote-pro-low-p-native-16-1-3-13-3-te.html (Fig. 7). A majority of the labour will be taken on by volunteers, including the initial removal 2 https://fernland.com.au/growrite-corflute-tree-guard-200mm-sides-450mm-high-green.html 3 https://www.seton.net.au/construction-mesh-shade-cloth.html#A36081 4 Volunteers include: MERGE, ENV334 and other Murdoch/Environmental volunteers. 9 5 Saxon hand trowel – Bunnings’s item number: 3361197 6 Hortex garden gloves – Bunnings’s item number: 3350173 7 Hortico 1.5L watering can – Bunning’s item number: 3110550 8 https://www.millersfencing.com.au/fencings/fencing-cost 9 Fowler, William M., Joseph B. Fontaine, Neal J. Enright, and Willa P. Veber. "Evaluating restoration potential of transferred topsoil." Applied Vegetation Science 18, no. 3 (2015): 379-390.

of all weed species and the initial planting of native saplings. Volunteer labour could also be used to further monitoring, cleaning, maintenance, and planting if required or requested. The fence costs include both the purchase and fitment of the materials for treated pine posts with steel star pick...