Recently, Riva and Fahrig revisited the SLOSS question with fresh data from Chase et al. (2019) and concluded that small patches (SP) are disproportionately important for biodiversity conservation compared to large patches (LP). They recommended that conservation priorities, canonically oriented toward LP, should shift to recognize the value of SP. We appreciate their new analysis, agree that SP have outstanding importance for maintaining diversity, and understand they do not suggest neglecting LP. However, we want to clarify two points. First, the political reality is that conservation decisions are rarely as clean cut as choosing to conserve one large patch versus several SP. Second, time lags and spatial dependencies in extinction dynamics severely complicate the interpretation that SP are better for biodiversity conservation.

Conservation biology does not happen in a void, and studies that seek to influence decision-making need to address political and institutional reality. Many countries, especially in the tropics, face recurring threats to biodiversity, including inside protected areas, and these threats are not distributed evenly across patch sizes, occurring more severely on SP (e.g., Reid et al., 2019). Even large reserves with highly restrictive human use face multiple threats including deforestation, changes in protection status, and/or area reduction. Moreover, the dismantling of environmental laws and institutions in charge of environment protection, currently happening in several countries (e.g., Vale et al., 2021), put at risk the role current reserves of any size have in protecting highly sensitive species and those that require large habitats.

Furthermore, the detection of high species richness and globally endangered species in SP, even the older ones, does not guarantee the local presence of viable populations. These patterns may result from past landscape connectivity, especially in highly dynamic landscapes (e.g., Atlantic Forest). Although fragmented for decades, landscapes may have only recently crossed extinction thresholds (Figure S2), sheltering declining populations and unpaid extinction debts (Lira et al., 2019). Furthermore, the presence of continuous/very large unprotected forest remnants (Figure S3) can act as biodiversity sources to SP. Very large habitat areas may be particularly important for maintaining sensitive and long-life cycle species in highly dynamic landscapes undergoing replacement of old growth with small, ephemeral forests (Rosa et al., 2021).

We advocate for diverse conservation portfolios that are tailored to regional ecological and political realities and include protecting and restoring SP and LP, as well as promoting landscape permeability in the agricultural matrix. In the current political environment, discussing changes to conservation priorities in reductionist terms can have dire consequences for the fate of LP, both protected and unprotected. Also, adding more SP to reserve systems could overwhelm defunded and overburdened public agencies. Alternatively, creating or reinforcing mechanisms to devolve the protection of SP to landowners would release public agencies from managing small reserves, allowing them to focus on avoiding deforestation (of both LP and SP) and managing large reserves. “Legal Reserves” (mandatory set aside areas inside landholdings) and “Private Natural Heritage Reserves” (voluntary) are examples already present in Brazilian law (Metzger et al., 2019) representing a great opportunity to protect SP, without the inherent risks of shifting conservation priorities.

最近，Riva 和 Fahrig 使用 Chase 等人的最新数据重新审视了 SLOSS 问题。( 2019) 并得出结论，与大斑块 (LP) 相比，小斑块 (SP) 对于生物多样性保护的重要性不成比例。他们建议，通常以 LP 为导向的保护优先事项应该转变为认识到 SP 的价值。我们赞赏他们的新分析，同意 SP 对于保持多样性具有突出的重要性，并且理解他们并不建议忽视 LP。但是，我们想澄清两点。首先，政治现实是，保护决策很少像选择保护一大片斑块而不是几个 SP 那样一刀切。其次，灭绝动态的时间滞后和空间依赖性使 SP 更利于生物多样性保护的解释严重复杂化。

保护生物学不会凭空发生，寻求影响决策的研究需要解决政治和制度现实。许多国家，尤其是热带国家，面临着对生物多样性的反复威胁，包括在保护区内，这些威胁在斑块大小上分布不均，在 SP 上更为严重（例如，Reid 等人，2019 年）。即使是人类使用受到高度限制的大型保护区也面临着多种威胁，包括森林砍伐、保护状态变化和/或面积减少。此外，目前在几个国家正在废除环境法律和负责环境保护的机构（例如，淡水河谷等人，2021), 危及任何规模的当前储备在保护高度敏感物种和需要大栖息地的物种方面的作用。

此外，在 SP 中检测到高物种丰富度和全球濒危物种，即使是较老的物种，也不能保证当地存在可存活的种群。这些模式可能源于过去的景观连通性，尤其是在高度动态的景观中（例如，大西洋森林）。尽管几十年来支离破碎，景观可能只是最近才跨过灭绝阈值（图 S2），庇护着不断下降的人口和未偿还的灭绝债务（Lira 等人，2019 年）). 此外，连续/非常大的未受保护的森林遗迹（图 S3）的存在可以作为 SP 的生物多样性来源。非常大的栖息地区域对于在高度动态的景观中维持敏感和长生命周期的物种可能特别重要，这些景观正在用短暂的小森林取代旧的生长（Rosa 等人，2021 年）。

我们倡导针对区域生态和政治现实量身定制的多样化保护组合，包括保护和恢复 SP 和 LP，以及促进农业矩阵中的景观渗透性。在当前的政治环境中，以还原论的方式讨论保护优先事项的变化可能会对受保护和未受保护的 LP 的命运产生可怕的后果。此外，向储备系统添加更多 SP 可能会使资金不足和负担过重的公共机构不堪重负。或者，创建或加强将 SP 的保护下放给土地所有者的机制将使公共机构免于管理小型保护区，从而使他们能够专注于避免森林砍伐（LP 和 SP）和管理大型保护区。2019 ) 代表了保护 SP 的绝佳机会，没有转移保护重点的固有风险。