Dozens of companies including industry giants McDonald’s, Unilever, Cargill and Mars已承诺to zero deforestation supply chains in the last five years, aiming to reduce their effect on forest landscapes. The potential impact is substantial: a handful of forest commodities—oil palm, beef, soy, and pulp and paper—account formore than 70 percent在热带森林中的所有森林砍伐。但是这些公司到底是什么？如何定义森林砍伐？进度如何衡量和监测？了解这些问题的答案可以帮助应对实施零供供应承诺的挑战，并确保商品生产不会损害世界的森林。

什么是森林？什么是森林砍伐？情况很复杂。

森林有多种形式，在组成，动植物和动物区系的组成，生物物理特征和多样性以及许多其他特征上有所不同。联合国环境计划认可more than 800 definitionsof forests. The Food and Agriculture Organization developed common criteria for forests for the Global Forest Resources Assessment (FRA), noting that a forest should have a minimum area, a minimum potential tree cover and a minimum tree height (see FRA 2010). But each country is free to define the thresholds within these criteria as they wish.

There are also many ways to define the loss of a forest, or deforestation. There aretwo main methods：一个看着loss of tree coveras an indicator of deforestation and another that looks at thechange inuse土地。根据土地利用定义，即使森林被清除，直到该地区以另一种方式开发或使用的农业，它才被视为森林砍伐。

Defining deforestation gets even more complicated due to variation within these two camps. For example, when measuring deforestation by tree cover loss, what counts as a tree? The University of Maryland counts trees more than 5 meters (5.46 yards) tall, Brazil defines deforestation based on trees that are twice that height. That causes discrepancies about exactly where tree cover exists and where loss occurs.

为了使混乱增加，大多数观看上面景观的卫星仍无法区分天然森林和林木种植园。森林清除可能实际上可能是收获的种植园。如果没有更多有关种植园的数据的数据，就很难说出要清除的内容。

Zero Deforestation versus Zero Net Deforestation

Zero deforestation and zero网森林砍伐are often used interchangeably, but they refer todrastically different forest accounting practices。零森林砍伐意味着没有清除或转化森林区域，而零净森林砍伐允许只要在其他地方重新种植一个相等的区域，就可以清除或转化一个区域的森林。但是，很难就如何定义和测量森林平等面积达成共识。可以测量森林的某些方面（例如它所含的碳），但是量化其生物多样性，文化或生态系统价值要困难得多。从理论上讲，森林面积的总范围与零森林砍伐保持不变，但森林面积的质量可能有很大差异。

What Do Company Policies Say?

Although often referred to as zero deforestation policies, corporate policies often address more than just activities related to the clearing of forests. They also detail other important elements of commodity production that go beyond banning deforestation. Most commonly, these policies include:

  • 在富含碳泥的泥炭土地上没有清理
  • No use of fires for clearing
  • 没有清理High Conservation Value (HCV)areas
  • No clearance onHigh Carbon Stock (HCS)areas
  • Respect for indigenous land rights
  • 获得当地社区的免费，事先和知情同意
  • Production only on legal lands
  • 不使用强迫或奴隶劳动
  • A commitment to transparency regarding their production practices

向前进

Despite the lack of consensus on how to define and measure forests, there is a lot that can be done to implement zero deforestation commitments and improve coherence across these commitments. The IDH Traceability Working Group and the高碳股票工作组have begun this effort.

除非公司对供应链有更好的可见性，确切地知道森林商品的来源，并使供应链可追溯和透明。有了更好的信息，有关商品在哪里生产的信息，以及公司，非政府组织和政府可以更好地了解森林在哪里被清理和负责。类似的工具Global Forest Watch Commoditiescan support efforts to monitor forest activity in commodity supply chains, though companies must concurrently make maps of commodity production areas public to enable better monitoring and the successful implementation of their commitments. Transparent supply chains also help avoid redundancies in audits, on-the-ground verification and monitoring that lets all companies improve sustainability at a lower cost.