Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Filters

2023 - 20252

Settings

Has files: YesSubject: search.filters.subject.410405 Environmental rehabilitation and restoration

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Soil recovery after Cyclone Gabrielle : building back better : a thesis presented in partial fulfilment of the requirements for the degree of Master of Environmental Management at Massey University, New Zealand
    (Massey University, 2025) Dickson, Alexandra
    Cyclone Gabrielle, which struck New Zealand’s North Island in February 2023, caused unprecedented damage to the North Island of New Zealand; the East Coast including Hawke’s Bay, Wairoa and Gisborne were some of the worst affected areas. As a result of the destructive flood waters, a vast amount of sediment was deposited on high-value horticultural and cropping land. In the aftermath, there was limited information available to guide landowners in restoring the productive capacity of this highly productive land (HPL). This research aimed to address knowledge gaps through a combined literature review and field-based study. The initial objective was to understand the geographical and geological setting of Hawke’s Bay and consolidate prior understanding of flood sediment impacts. Baseline soil and sediment data was collected from a range of affected sites shortly after the cyclone, assessing physical, chemical, and biological characteristics. A subset of these sites was revisited twelve months later to evaluate short term changes and management outcomes. Results showed that sediment characteristics varied widely by texture and catchment, with sandy sediments presenting significant physical and fertility challenges. From 2023 to 2024 there was positive outcomes nutrient levels, linked to fertiliser application, and incorporation of sediment into antecedent soil. Soil organic matter levels were consistently low and continued to decline, and earthworm populations remained suppressed. Despite variability in management responses, some growers observed improvements in soil physical properties, particularly where early interventions such as regrassing were employed. This research highlights the importance of rapid dissemination of management advice immediately after a flood, the need for longer-term monitoring to understand medium to long-term impact and recovery, and the value of coordinated knowledge storage for future events. The findings provide practical insights for growers and policymakers and lay the groundwork for further research into the economic and ecological dimensions of flood sediment recovery in high-value vegetable and horticultural systems, on highly productive land.
  • Thumbnail Image
    Item
    Combating biodiversity decline in coastal waters with intertidal eco-engineering and Green Gravel : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biological Science at Massey University, Albany, New Zealand
    (Massey University, 2023) Lis, Ella
    Biodiversity generates a multitude of benefits for humanity, such as food provision, maintenance of clean air and water, climate regulation, and soil erosion prevention. Widespread human activities in the oceans continue to cause declines in species diversity and abundance, threatening ecosystem services and ecological stability. The persistence of biogenic habitats emerges as a critical countermeasure against biodiversity loss and the preservation of ecosystem health. This thesis examines the effects of engineered coastal structures for rockpool biodiversity and a kelp forest restoration technique termed Green Gravel. In Chapter Two, I analysed differences in the biodiversity of natural and artificial rockpools, including riprap and concrete structures. Riprap and concrete exhibited comparable taxa richness and functional group prevalence to natural substrates; however disturbances, particularly smothering, significantly reduced taxa richness in all habitats. Distinct taxa associations emerged in response to disturbance and habitat type with encrusting algae and grazers favouring riprap habitats with normal pool conditions, and surprisingly, artificial structures showed resistance to nonindigenous species. This chapter underscores the importance of microhabitat diversity in supporting species and ecosystem health on artificial structures, guiding eco-engineering strategies to optimize their ecological value while accommodating inevitable urbanization. In Chapter Three, I explore the efficacy of different Green Gravel methodologies for restoring collapsed Ecklonia radiata forests and investigate the impact of environmental conditions on gravel retention and sporophyte length. Gluing gravel to the substrate significantly improved gravel retention, and interestingly sporophyte lengths varied between attachment methods, with sporophytes on placed gravel initially being 100mm shorter than sporophytes on glued Green Gravel. Notably, these initial differences in sporophyte length between placed and glued Green Gravel disappeared by the end of the experiment indicating that placed Green Gravel experienced greater growth toward the end of the experiment. Despite having 40% lower retention than glued Green Gravel, 20% of placed Green Gravel were still present after 14-months offering significant restoration potential, especially for resource-restricted community groups. Due to the relative ease of implementation, Green Gravel offers promise as a tool for community-led active marine restoration and ameliorating some of the challenges our declining kelp forests face. Addressing these biodiversity declines requires immediate and collective endeavors to facilitate transformative changes that foster nature conservation, restoration, and sustainable resource utilization, all while striving to achieve overarching global societal objectives.