Combining data from field surveys and archaeological records to predict the distribution of culturally important trees

Abstract

Aim: Indigenous communities involved in conservation planning require spatial datasets depicting the distribution of culturally important species. However, accessing datasets on the location of these species can be challenging, particularly when the current distribution no longer reflects areas with the full range of suitable growing conditions because of past logging. We test whether using occurrence data from community-based field surveys and archaeological records in species distribution models can help predict the distribution of monumental western redcedar trees (Thuja plicata)-large, high-quality trees suitable for cultural purposes such as carving dug-out canoes, totem poles and traditional houses. This species is critically important to indigenous people of the Pacific Northwest of North America, but trees suitable for traditional carving and building are diminishing in abundance due to logging.Location: Our analysis covers the spatial extent of the traditional territory of the Heiltsuk First Nation, which encompasses a portion of the Great Bear Rainforest in British Columbia, Canada. Methods:We built and compared species distribution models using the machine learning program, Maxent, based on occurrence data from field surveys and archaeological records of culturally modified trees.Results: Our findings highlight similarities and differences between the predictions from these species distribution models. When validating these models against occurrences from an independent dataset, the archaeological record model performs better than the field survey model. These findings may arise because the independent dataset was collected on an unlogged island-an environment that aligns more closely with the historic forest conditions revealed by the archaeological records than the current distribution revealed by the field surveys. Main conclusions:We demonstrate and discuss the utility of using archaeological data in species distribution modelling and conservation planning when the target species is associated with shifting environmental baselines, data limitations and an important cultural resource. ACK N OWLED G EM ENTSWe are extremely grateful to all the staff at the Heiltsuk Integrated Resource Management Department for guiding this project, providing logistical support and supplying datasets, especially Laurie

Using Traditional Ecological Knowledge to Understand the Diversity and Abundance of Culturally Important Trees

“…Indigenous people in this region, similar to many cultural groups in the Pacific Northwest of North America, use this species extensively for cultural practices related to clothing, transportation, housing, and spirituality-these myriad uses have led to redcedar being described as "the tree of life" (Garibaldi and Turner 2004;Stewart 1995;Zahn et al 2018). Western redcedar is a common species in some coastal ecosystems (Green and Klinka 1994), but the largest growth forms that are suitable for carving dugout canoes, totem poles, large ceremonial masks, and traditional buildings are rare (Benner et al 2019;Sutherland et al 2016; Figure 1). This scarcity stems from industrial forestry practices that target these trees' highly valued timber (Green 2007), as well as the unique environmental conditions, including many centuries of growth (Daniels 2003), required for trees to develop the large sizes and other morphological characteristics suitable for carving large logs.…”

Biocultural indicators to support locally led environmental management and monitoring

“…Prior to European colonization, which brought smallpox epidemics and deliberate cultural genocide resulting in rapid depopulation, there were hundreds of villages and camps, seasonal and permanent, scattered along the coastline in the region (Cannon 2002). There is a rich diversity of language groups, with distinct cultural practices and lineages, composed of different clans (Beck 2000). Indigenous laws, hereditary leadership, and the potlatch system governed how, where, and by whom resources were used and stewarded (Trosper 2002, Brown andBrown 2009).…”

“…Cultural uses of western redcedar trees require specific morphological characteristics, which are associated with different stand structures. For example, stands of trees that contain characteristics such as a large diameter, straight grain, and sound bole may be considered "monumental trees" that are suitable for cultural practices such as canoe building, totem carving, or mask carving (Council of the Haida Nation 2013, British Columbia Ministry of Forests, Lands, and Natural Resource Operations 2016, Sutherland et al 2016, Benner et al 2019). Because of the structural complexity in stands containing monumental cedar, these stands also provide valuable habitat for many other species, as well as gene and carbon stores (DellaSalla et al 2011, Lertzman and Mackinnon 2014, Sutherland et al 2016.…”

“…Because of the structural complexity in stands containing monumental cedar, these stands also provide valuable habitat for many other species, as well as gene and carbon stores (DellaSalla et al 2011, Lertzman and Mackinnon 2014, Sutherland et al 2016. In some cases, these stands may also contain culturally modified trees that provide archaeological evidence of historic occupation and land use in addition to a direct connection between community members alive today and their ancestors (Cuerrier et al 2015, Earnshaw 2017, Benner et al 2019. These characteristics of western redcedar make for an indicator that exemplifies the pairing of content (habitat and valuable materials) and context (cultural ties to place).…”

“…In systems where management impacts have the potential to affect nonrenewable values, such as cultural heritage, there is a need for indicators that can be assessed rapidly and accurately to inform EM (United Nations Educational, Scientific, and Cultural Organization 2003, Cuerrier et al 2015, Sterling et al 2017a. For example, a long history of commercial logging in coastal British Columbia that has targeted high-quality cedar has precipitated a decline of both monumental cedar and culturally modified trees (Guujaaw 1999, Turner et al 2009, British Columbia Ministry of Natural Resource Operations and Ministry of Forests, Mines and Lands 2011, Earnshaw 2017, Benner et al 2019.…”