An ecosystem services perspective of Lake Wairarapa: Insights from the past, present, and toward the future

Abstract

<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>

Understanding Causes of Water Quality Decline in an Aotearoa New Zealand Ecosanctuary through Paleoenvironmental Analysis

“…The rapid deterioration of water quality observed at Rotokare aligns with trends across Aotearoa, where many lakes have quickly changed trophic status, characterised by increased phytoplankton biomass, increased turbidity, and alternations in ecosystem structure (see Gregersen et al, 2022;Halford, 2019;Parrish, 2020;Short et al, 2022). However, as mentioned previously, the timeframe between known human (particularly European) arrival at Rotokare and degradation of water quality is uncommonly prolonged.…”

“…Studies examining the long-term history of lake ecosystems and water quality in Aotearoa describe previously stable lake systems prior to human arrival, (e.g., Lake Nganoke (Parrish, 2020) and Lake Wairarapa (Halford, 2019)), low phytoplankton populations (e.g., Lake…”

“…European arrival, generally identified at ~1850 CE (see Halford, 2019;Parrish, 2020;Short et al, 2022). The persistence of a stable ecosystem at Rotokare following human, particularly European, arrival to the region is atypical and distinguishes it from other catchments in Aotearoa.…”