Life cycle assessment is a valuable tool for evaluating the environmental performance of different products and services. According to the European Commission, forests are indispensable and the most effective strategy for climate change mitigation, although raw wood products (roundwood, pulpwood and fuelwood) are not carbon neutral as previously thought because of the human activities during forest management processes. Apart from climate change, the production of raw wood products also contribute to other environmental impact categories. Previous studies have shown that the life cycle inventory (LCI) data for raw wood products should be collected from the site-specific not from more generic sources because of the significant differences in several geography- and technology-dependent factors. However, less discussed are time-dependent factors, which should also be acknowledged especially because of the long growing time of trees. By analysis of the forest management history, the main objective of the presented study was to determine which forest management activities were performed during the growth phase of currently harvested birch (Betula spp.) roundwood in Latvia and, based on these results compile the LCI. The results of the forest management history analysis showed that for currently produced birch roundwood only logging operations should be considered in the LCI. Subsystems such as seed production, seedling production and silvicultural operations were not practiced or had only minor impact due to low mechanization level in the past. By taking into account the time-dependent factors (forest management practice, technology, legislation and composition of used chemicals), the LCI was developed and can be used in further calculations of environmental impacts for different wood-based products that are manufactured from currently harvested birch roundwood in Latvia.

生命周期评估是评估不同产品和服务的环境绩效的宝贵工具。根据欧洲委员会的说法，森林是必不可少的，也是缓解气候变化最有效的策略，尽管原木产品（原木，纸浆木和薪材）并非碳中性，因为森林管理过程中的人为活动导致了森林的碳中和。除了气候变化之外，原木产品的生产还有助于其他环境影响类别。先前的研究表明，由于某些与地理位置和技术有关的因素存在显着差异，因此应从特定地点收集原始木材产品的生命周期清单（LCI）数据，而不是从更一般的来源中收集数据。但是，与时间相关的因素很少讨论，特别是由于树木的长生时间，这一点也应得到承认。通过对森林经营历史的分析，本研究的主要目的是确定在当前收获的桦树生长阶段进行了哪些森林经营活动（拉脱维亚的桦木（Betula spp。）圆木，并根据这些结果编制了LCI。森林经营历史分析的结果表明，对于目前生产的桦木圆木，LCI中应仅考虑伐木作业。由于过去的机械化水平较低，因此尚未实施子系统，例如种子生产，幼苗生产和造林操作，或者只产生了很小的影响。通过考虑与时间有关的因素（森林管理实践，技术，法规和使用过的化学品的成分），开发了生命周期清单，可将其用于进一步计算从当前采伐的木材中提取的各种木质产品对环境的影响在拉脱维亚的桦木圆木。