Many impact-based studies rely on quantitative data alone to gain site information and impact measurements with little explanation of how management drivers and stakeholder motivations can affect management decisions. Here we have used a combination of qualitative and quantitative data in order to gather a more complete picture on how a complex wildlife management situation can result in different impacts on protected woodland habitats. As well as assessing habitat impact through vegetation surveys we have used semi-structured interviews to successfully gain information from landowners regarding site characteristics but also to elicit their attitudes regarding deer impact and management. Interview-based approaches have been criticised for possible variation in the delivery of the questions influencing responses, as well as possible discrepancies between what people report and what they actually feel or do. However, we considered interviews to be the most effective way to obtain detailed information from our sample of landowners as personal interviews tend to elicit attitudes and perceptions more accurately than posted questionnaires, telephone surveys or electronic surveys. In addition, while this analysis may be specific to the landowners in this sample, it is highly likely that similar attitudes exist amongst landowners and land managers of sites with comparable habitat and deer species composition in other areas.
The current awareness among landowners of the detrimental ecological impacts of deer was reflected in the qualitative results, since all but one of the landowners who were actively managing deer perceived these impacts as a problem, regardless of whether financial or ecological reasons were their main drivers for management. Moreover, the interviews showed that landowners are continually reminded of these impacts through communications with organisations such as the Deer Initiative, Natural England and the Forestry Commission, as well as in conversations with their neighbours and through personal observations. Therefore, ecological motivations for management are strong, but our results showed that management measures conducted at single sites to reduce ecological impact are limited in their effectiveness in terms of variables such as species richness. In contrast with ecological motivations, financial motivations for management showed no significant associations with any of the ecological response variables. This contrast between the importance of ecological and financial motivations suggests that landowners primarily acting on these different motivations may exhibit differences with respect to the type of deer management they pursue. Most significantly, the existence of collaborative deer management was correlated positively and significantly with bluebell abundance in the mixed modelling. However, bluebell populations in the area may also be reacting to a range of other environmental factors other than deer grazing. Nationally in the UK, bluebells are in decline due to loss of habitat, especially woodlands and hedgerows, picking and uprooting, tipping of garden waste and hybridisation with Spanish bluebells.
The RDA biplot represented 66% of the explained variation in ecological impact and was therefore a reasonable representation of the fitted data obtained in the multivariate analysis. Any unexplained variation could reflect the complexity of the relationships, and their mixed environmental and social nature. It may be that an increased sample size in terms of the number of different individual woodlands would have resulted in increased explanatory power of the model. However, this increase is unlikely to have been significant since our sample did account for 17 of the 54 of all SSSI woodlands in unfavourable condition in the county of Suffolk.
Management was clearly well-established on sites which were being managed for primarily conservation purposes. However, our results suggest that the ecological benefits derived from this site-specific management were limited. Whilst there was some indication that seedling density was increased as a result of such management, other measures of ecological impact such as species richness, foliage density and bluebell abundance were all negatively associated with ecological motivations for management and the site-specific management approach. However, this could indicate that sites were being managed with ecological motivations in mind because they were lacking in these ecological indicators and yet had not yet recovered in terms of these variables, despite the management. Sites which were being managed for primarily economic motivations showed relatively greater conservation benefits, such as increased foliage density and a higher abundance of bluebells, even though these were not the primary objective of management and despite higher deer activity indices. These results suggest that the on-site management is currently relatively ineffective in terms of managing for conservation objectives such as increasing species richness, and may
go some way to explaining the large number of woodlands managed for conservation purposes which are still in unfavourable condition due to deer grazing or browsing. Although collaborative management in our study area was primarily associated with economic motivations, the evidence suggests that a greater adoption of this landscape-scale approach to deer management may also bring wider benefits in terms of conservation objectives.
In both the redundancy analysis and the mixed model results, we found that canopy cover correlated negatively with foliage density. Foliage density can be reduced by a combination of browsing and shade and such reductions can have detrimental impacts on bird species that depend on low vegetation within the woodland ecosystem. Our results indicated that the effect of canopy cover was significantly negative for lower height levels of foliage density, but that, where collaborative deer management was taking place, canopy cover did not have a negative association with foliage density at the 150–200 cm height level. It is likely that canopy cover is compounding the effect of browsing at the lower levels by species such as muntjac and roe deer, the latter of which has a browsing range of 0 to 150 cm above soil level. Foliage above this height will be browsed by the larger deer species present in the area, such as fallow. In conjunction with the results above, these observations provide further evidence that conservation benefits at specific sites are more likely to be achieved through management conducted collaboratively at the landscape level than through on-site actions alone.
By including social factors in our analysis, we have enhanced previously limited understanding of the deer management system taking place on sites managed for conservation. The results have important implications for future deer management and policy decisions. For the conservation sites sampled here, where landowners are managing deer for ecological reasons, their management decisions seem to be influenced by site ecology, especially in terms of the abundance of nationally important and easily identifiable plant species, as well as by information from external organisations and informal communications with their neighbours. Tradition and a desire to maintain a healthy deer herd were also considered as important motivations for managing deer by many landowners. While financial incentives to manage were not significant in any of the modelled results, many landowners stated that this was an important driver enabling them to actively manage deer. Various English woodland grant schemes in particular were mentioned on number of occasions by landowners. These grants are provided by the Forestry Commission and one of the main aims of the scheme is to increase the public benefits given by existing woodlands. Maintaining such financial aid is therefore likely to continue to be an important driver for deer management for many SSSI landowners.
While we have found that the ecological impacts of deer are widely recognised, we have found no evidence that deer management focused at the level of individual sites is currently effective for achieving the ecological management objectives of these sites. On sites where existing site-specific management is failing to control deer impacts, our results suggest that management efforts may be more effective when undertaken collaboratively at landscape level. In fact, we have shown for the first time that collaborative management of deer, irrespective of its motivations, can deliver ecological benefits. Because of the economic motivations underlying much collaborative management, this management tends to be focused on the larger deer species, although the smaller species, such as muntjac, also have the potential for impact on conservation interests. Collaborative landscape-scale deer management will therefore need to take account of these other species if conservation objectives are to be met within areas containing significant numbers of these species as part of their multi-species deer system. These results provide new evidence concerning the interaction between ecological and social factors in affecting deer impact on conservation woodlands, and highlight the importance of integrating human dimensions with ecological analysis to enhance the understanding of complex wildlife management situations in conservation.
在这里,我们使用了定性和定量数据相结合,以收集复杂的野生动物管理情况如何导致在受保护的林地栖息地不同的影响更完整的画面。以及评估通过植被调查,栖息地的影响,我们采用半结构化面试,成功获得来自有关网站的特点地主信息,而且还征求他们对鹿的影响和管理的态度。采访为基础的方法已经被批评为可能变化的影响反应的问题交付,以及与什么人举报的可能差异,以及他们真实感受到或做 。但是,我们认为面试是获得我们的地主样本的详细信息,个人访谈往往引起态度和看法比更准确地发布调查问卷,电话调查或者电子调查最有效的方法。此外,虽然这种分析可能是特定于该样品中的地主,它极有可能存在的站点之间具有可比性的栖息地和鹿种成分在其他领域的土地所有者和土地经营者类似的态度 。
鹿的不利生态影响的土地所有者之间的电流意识反映在定性结果,因为所有,但谁是积极管理的鹿认为这些影响是一个问题,地主之一,无论经济或生态的原因是否是他们的主要驱动管理。此外,访谈表明,地主通过与组织,如鹿倡议,自然英格兰和林业委员会,以及在与邻国的对话,并通过个人的观察通信不断提醒这些影响。因此,生态动机的管理能力很强,但我们的研究结果表明,在单一地点进行,以减少生态影响的管理措施是有限的在他们的变量,例如物种丰富度方面的有效性 。在生态动机相反,财务动机管理未见显著协会与任何的生态响应变量。生态和经济动机的重要性之间的这种反差表明,土地所有者,主要作用于这些不同的动机可能表现出相对于鹿管理他们所追求的类型不同 。最显著,协同鹿管理存在呈正相关,并与显著风信子丰富的混合建模。然而,风铃草种群在该地区也可以被反应的范围内比鹿放牧等其他环境因素。在全国范围内,在英国,风铃草都在下滑,由于栖息地丧失,特别是林地和灌木篱墙,采摘和连根拔起,园林废弃物和杂交引爆西班牙风信子 。
管理层显然对这些人正在为主要保护目的管理网站行之有效的 。然而,我们的研究结果表明,从本网站特定的管理产生的生态效益是有限的 。虽然有一些迹象表明,苗木密度增加为这种管理的结果,对生态影响的其他措施,如物种丰富度,枝叶密度和风信子丰均负生态动机管理和现场的具体管理办法有关。然而,这可能表明站点正在与生态动机记管理,因为它们缺乏在这些生态指标,但还没有回收这些变量而言,尽管管理 。它正在对主要经济动机管理网站显示,相对较大的保护益处,如增加枝叶密度和更高的丰风信子,尽管这些人不是管理的首要目标,尽管较高的鹿活动指数。这些结果表明,现场管理,目前管理的保护目标,如增加物种丰富度方面相对无效,并可能在一定程度上解释为保护目的而仍处于不利的条件下,由于大量的林地管理鹿放牧或浏览。虽然协同管理在我们的研究领域主要是与经济动机有关,有证据表明,更大的采用这种景观尺度的方法来管理鹿也可以在保护目标方面带来更大的好处。
在这两个冗余分析和混合模型结果,我们发现,篷盖与叶子的密度呈负相关 。叶子密度可以通过浏览和色光和这种减少的组合来减少可能对依赖于低植被林地生态系统内的鸟类物种的有害影响。我们的研究结果表明,篷盖的效果显著阴性枝叶密度较低的高度水平,但是,在协同管理鹿正在发生,篷盖没有与叶子的密度在150-200厘米高的水平呈负相关。很可能篷盖复利浏览较低级别由物种,如麂和狍,后者为0〜150厘米以上土壤层次的浏览范围内的效果 。叶子上面这个高度就会由较大鹿物种中存在的区域,如休耕浏览 。与上述结果相结合,这些意见提供进一步的证据表明,在特定地点的保护效益更可能通过在比通过现场单独行动的景观水平进行协同管理来实现 。。