Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Backfill canals or trenches: freshwater marshes Three studies evaluated the effects, on vegetation, of backfilling canals or trenches in freshwater marshes. All three studies were in the USA. There was overlap in the canals used in two of the studies. VEGETATION COMMUNITY Overall extent (3 studies): Three replicated studies in freshwater marshes in the USA reported coverage of emergent marsh vegetation between 6 months and 25 years after backfilling. All three studies reported that coverage was greater on former spoil areas alongside canals than within the partly filled canal channels. Relative abundance (1 study): One replicated, paired, site comparison study in a freshwater marsh in the USA reported that in levelled former spoil areas alongside backfilled canals, the relative abundance of some key plant species differed from natural marshland. Vegetation was surveyed three years after backfilling. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2987https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2987Thu, 25 Mar 2021 21:10:33 +0000Collected Evidence: Collected Evidence: Backfill canals or trenches: brackish/salt marshes Four studies evaluated the effects, on vegetation, of backfilling canals or trenches in brackish/salt marshes. All four studies were in the USA. There was overlap in the canals used in three of the studies. All studies included some freshwater areas in some analyses, but all results are based predominantly on canals in brackish or saline marshes. VEGETATION COMMUNITY Overall extent (4 studies): One paired, site comparison study in marshes in the USA reported that emergent vegetation coverage was typically lower in backfilled canals, after four years, than in adjacent undisturbed marsh. Three other studies in marshes in the USA simply reported coverage of emergent marsh vegetation between 6 months and 25 years after backfilling canals. All four studies reported that coverage was greater on former spoil areas alongside canals than within the partly filled canal channels. Two of the studies also reported the frequency of submerged/floating vegetation after 6–60 months, and one reported coverage of upland plant species on spoil banks that had not been completely levelled after 6–11 years. Overall richness/diversity (2 studies): One replicated, site comparison study in marshes in the USA reported that former spoil areas alongside backfilled canals had greater plant species richness than nearby natural marsh, due to the presence of upland species on unlevelled areas. One other study of a backfilled canal in predominantly brackish and saline marshes in the USA simply quantified richness of submerged vegetation four years after backfilling. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2988https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2988Thu, 25 Mar 2021 21:10:50 +0000Collected Evidence: Collected Evidence: Backfill canals or trenches: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of backfilling canals or trenches in freshwater swamps. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2989https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2989Thu, 25 Mar 2021 21:10:54 +0000Collected Evidence: Collected Evidence: Backfill canals or trenches: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of backfilling canals or trenches in brackish/saline swamps. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2990https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2990Thu, 25 Mar 2021 21:11:05 +0000Collected Evidence: Collected Evidence: Plug/dam canals or trenches: freshwater marshes One study evaluated the effects, on vegetation, of plugging/damming canals or trenches in freshwater marshes. The study was in the USA. VEGETATION COMMUNITY Overall extent (1 study): One replicated, site comparison study of backfilled canals in freshwater marshes in the USA reported that emergent marsh vegetation coverage was greater within the channels of plugged than unplugged canals, after 6–60 months. However, coverage on former spoil areas did not significantly differ between plugged and unplugged canals. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2991https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2991Mon, 29 Mar 2021 12:08:23 +0100Collected Evidence: Collected Evidence: Plug/dam canals or trenches: brackish/salt marshes Two studies evaluated the effects, on vegetation, of plugging/damming canals or trenches in brackish/salt marshes. Both studies were in the USA. There was overlap in the canals used in the studies. Both studies included some freshwater areas in some analyses, but all results are based predominantly on canals in brackish or saline marshes. VEGETATION COMMUNITY VEGETATION ABUNDANCE Overall abundance (2 studies): Two replicated, site comparison studies studied emergent vegetation of backfilled canals in the USA. One study reported that plugged canals had greater coverage of emergent marsh vegetation than unplugged canals after 6–60 months. One study found that emergent vegetation coverage on former spoil heaps did not significantly differ alongside plugged and unplugged canals after 6–11 years. The first study also reported that plugged canals were more likely to contain floating/submerged vegetation than unplugged canals. VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2992https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2992Mon, 29 Mar 2021 12:08:35 +0100Collected Evidence: Collected Evidence: Plug/dam canals or trenches: freshwater swampsWe found no studies that evaluated the effects, on vegetation, of plugging/damming canals or trenches in freshwater swamps. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2993https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2993Mon, 29 Mar 2021 12:08:51 +0100Collected Evidence: Collected Evidence: Plug/dam canals or trenches: brackish/saline swampsWe found no studies that evaluated the effects, on vegetation, of plugging/damming canals or trenches in brackish/saline swamps. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2994https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2994Mon, 29 Mar 2021 12:09:11 +0100Collected Evidence: Collected Evidence: Design transportation or service corridors to maintain water flowWe found no studies that evaluated the effects, on vegetation, of designing infrastructure to maintain water flow into/out of marshes or swamps. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2995https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2995Mon, 29 Mar 2021 12:29:29 +0100Collected Evidence: Collected Evidence: Retain/create habitat linkages across service corridorsWe found no studies that evaluated the effects, on marsh/swamp vegetation, of retaining or creating habitat linkages across transportation or service corridors. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2996https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2996Mon, 29 Mar 2021 12:33:06 +0100