It is generally assumed that when natural habitat is converted to human-dominated cover such area is “lost” to its native species. Extinctions will ensue. The literature generally assumes that species are extirpated as natural area is reduced, following the well-known species-area relationship (SAR). However, SARs have consistently over-estimated species losses resulting from conversion of natural habitat to human-dominated land covers. We hypothesize that the overestimation occurs because these area-based models assume that converted habitat is “lost”, eliminating all species. However, in the real world, conversion of natural land cover to human-dominated cover frequently produces new land covers, different from the original habitat, but not necessarily completely inhospitable to biodiversity. We evaluated the responses of total avian richness, forest bird richness and open habitat bird richness to remaining natural area within 991 quadrats, each 100 km2, across southern Ontario. Total bird species richness does not follow SAR predictions; rather, the number of bird species peaks at roughly 50% natural land cover. The richness of forest birds does follow the usual SAR power-law as a function of forested area. In contrast, richness of birds that prefer open-habitat does not increase monotonically with either natural- or human-dominated land cover. However, we can partition human-dominated land cover into an “available human-dominated” component and “lost” habitat. Richness of open-habitat species relates to the amount of available human-dominated cover. Distinguishing three habitat types (natural, available human-dominated, and lost) permits accurate predictions of species losses in response to natural habitat conversion.

It is generally assumed that when natural habitat is converted to human-dominated cover such area is “lost” to its native species. Extinctions will ensue. The literature generally assumes that species are extirpated as natural area is reduced, following the well-known species-area relationship (SAR). However, SARs have consistently over-estimated species losses resulting from conversion of natural habitat to human-dominated land covers. We hypothesize that the overestimation occurs because these area-based models assume that converted habitat is “lost”, eliminating all species. However, in the real world, conversion of natural land cover to human-dominated cover frequently produces new land covers, different from the original habitat, but not necessarily completely inhospitable to biodiversity. We evaluated the responses of total avian richness, forest bird richness and open habitat bird richness to remaining natural area within 991 quadrats, each 100 km2, across southern Ontario. Total bird species richness does not follow SAR predictions; rather, the number of bird species peaks at roughly 50% natural land cover. The richness of forest birds does follow the usual SAR power-law as a function of forested area. In contrast, richness of birds that prefer open-habitat does not increase monotonically with either natural- or human-dominated land cover. However, we can partition human-dominated land cover into an “available human-dominated” component and “lost” habitat. Richness of open-habitat species relates to the amount of available human-dominated cover. Distinguishing three habitat types (natural, available human-dominated, and lost) permits accurate predictions of species losses in response to natural habitat conversion.

In this thesis, the impact of conservation banking on biodiversity is assessed by examining the bird species richness in U.S. counties that have implemented the policy. Conservation banking is a market-based instrument designed for developers who need to comply with the Endangered Species Act for the negative environmental impacts that their projects have made. Conservation banking aims to “protect and recover imperilled species and the ecosystems upon which they depend” (USFWS 2013, p. 1). In this thesis, a staggered difference-in-difference with differential timing by Goodman-Bacon (2018) and further developed by Callaway and Sant’Anna (2021) is used to estimate the effect of conservation banks on biodiversity. Data for biodiversity, bird species richness are collected from U.S. Geological Survey's data from the North American Breeding Bird Survey (BBS). Information on conservation banks is gathered from the Regulatory In-lieu fee and Bank Information Tracking System (RIBITS). This thesis focuses on 107 conservation banks in 53 counties in the U.S. established between 2005 and 2016. The main results from this study indicate a positive impact of the introduction of conservation banks, with an increase in biodiversity of 4,1%. Consequently, this confirms the positive effect of the policy intervention. Despite these results, it is vital to consider caution regarding this market-based instrument. Market-based instruments that commodify elements of nature into the market are a new frontier in capitalist expansion. This approach may exclude areas from the natural evolutionary selection process, leading to potential long-term ecological imbalances. Current payment structures in conservation banking can lead to misallocation of taxpayers’ money at the same time as biodiversity outcomes are not optimized. Therefore, the most fundamental recommendation for this policy is to change to outcome-based payments.