No abstract

Purpose Planting strategies can be effective mechanisms to reduce diffuse pollution from agricultural catchments reaching water bodies. Plants with antimicrobial properties such as mānuka (Leptospermum scoparium) demonstrated in controlled conditions the ability to inhibit nitrification and growth of pathogens in soils. This potential in a real on-farm setting was still to be investigated. Methods In a stock-excluded riparian area, planted with mānuka on a dry stock farm, synthetic excrement patches high in urea (950 kg N ha−1 equiv.) and Escherichia coli (7.9 × 109 cfu plant-1) underneath mānuka saplings and pasture were applied. Soil was sampled at three depths over 21 days after the excrement application and analysed for total C and N, inorganic N, pH, soil moisture and E. coli. Results There was no significant difference between the pasture and mānuka for total C and N, C:N ratio, and soil moisture. E. coli was only different between both at 20–30 cm deep. NO3− - N and NH4+ - N concentrations were significantly lower under mānuka compared to pasture for the upper two soil depths (NO3− - N: 109 mg kg−1 vs 205 mg kg−1 in the topsoil). Conclusions The results of this study indicate that mānuka may inhibit urease activity and nitrification and could reduce on-farm nitrate leaching, while also highlighting that field conditions make quantifying such phenomenon more complex.

<p>Ecosystem services encompass the wide range of intrinsic and extrinsic benefits that humans derive from ecosystems and how such services contribute to community wellbeing. The delivery of effective and efficient provisioning, regulating, and cultural ecosystem services at Lake Wairarapa (a shallow, super-trophic, coastal lake in the lower North Island) has been heavily impacted through current land use. Using a pragmatic epistemology and mixed methods approach, this research sought to understand the past, present, and future delivery of ecosystem services at Lake Wairarapa through three distinct, yet complementary, studies.  Firstly, a palaeo-environmental reconstruction using five proxies was completed to build an understanding of past environmental conditions at Lake Wairarapa. Prior to human arrival, the lake was stable and resilient in response to environmental perturbations. However, alteration of the landscape following human arrival has reduced ecosystem service effectiveness, prompting a transition into an entirely new environmental state at Lake Wairarapa. This chapter highlighted the abrupt removal of mānuka and centennial shift from a forest catchment into one dominated by agriculture so a field trial was conducted to assess the ability of mānuka to reduce nitrogen leaching and E. coli contamination. Mānuka can significantly reduce the conversion of ammonium to nitrate compared to pasture, thus regulating nitrate leaching; however, the impact on E. coli counts was less conclusive. Finally, cultural services present at Lake Wairarapa and future community aspirations were assessed through seven semi-structured interviews of Wairarapa community members. Place attachment was recognised as the underlying factor that facilitated strong cultural service delivery. Social and environmental restoration was identified as the key vision for the future, underpinned by collaboration within resource management.  From this research, four recommendations were made to enhance ecosystem service delivery at Lake Wairarapa: establishment of ecologically appropriate restoration plans, facilitated collaborative management, further investigation of environmental and economic properties of mānuka, and development of community engagement programmes. This multi-disciplinary and holistic approach outlines a pathway towards a positive and inclusive future for Lake Wairarapa and its communities.</p>

<p>Ecosystem services encompass the wide range of intrinsic and extrinsic benefits that humans derive from ecosystems and how such services contribute to community wellbeing. The delivery of effective and efficient provisioning, regulating, and cultural ecosystem services at Lake Wairarapa (a shallow, super-trophic, coastal lake in the lower North Island) has been heavily impacted through current land use. Using a pragmatic epistemology and mixed methods approach, this research sought to understand the past, present, and future delivery of ecosystem services at Lake Wairarapa through three distinct, yet complementary, studies.  Firstly, a palaeo-environmental reconstruction using five proxies was completed to build an understanding of past environmental conditions at Lake Wairarapa. Prior to human arrival, the lake was stable and resilient in response to environmental perturbations. However, alteration of the landscape following human arrival has reduced ecosystem service effectiveness, prompting a transition into an entirely new environmental state at Lake Wairarapa. This chapter highlighted the abrupt removal of mānuka and centennial shift from a forest catchment into one dominated by agriculture so a field trial was conducted to assess the ability of mānuka to reduce nitrogen leaching and E. coli contamination. Mānuka can significantly reduce the conversion of ammonium to nitrate compared to pasture, thus regulating nitrate leaching; however, the impact on E. coli counts was less conclusive. Finally, cultural services present at Lake Wairarapa and future community aspirations were assessed through seven semi-structured interviews of Wairarapa community members. Place attachment was recognised as the underlying factor that facilitated strong cultural service delivery. Social and environmental restoration was identified as the key vision for the future, underpinned by collaboration within resource management.  From this research, four recommendations were made to enhance ecosystem service delivery at Lake Wairarapa: establishment of ecologically appropriate restoration plans, facilitated collaborative management, further investigation of environmental and economic properties of mānuka, and development of community engagement programmes. This multi-disciplinary and holistic approach outlines a pathway towards a positive and inclusive future for Lake Wairarapa and its communities.</p>